Seed propagation

　　1. Seed collection, selection and storage

　　When the seeds are mature, they should be collected in time. Select mother plants that are typical, excellent in traits, lush, free of pests and diseases, and in their prime to collect seeds. When harvesting different types of flower seeds, you must understand their maturity characteristics and harvest them in time. For example, the seeds of Salvia affine are dark brown, the seeds of Dianthus chinensis are black, the fruit skin of Viburnum tianmuensis is red, and the seeds of Peony stanzania are black. Some species, such as Impatiens, Butterfly Flower, Delphinium, Petunia, Weigela, and Lilac, have fruits that are easy to crack, so they need to be harvested in time before they crack to avoid the seeds from scattering. Some seeds mature one after another, such as Lycium barbarum, Buddaria japonica, Salvia affine, etc., which need to be observed at any time and harvested in time.

　　After the seeds are harvested, they should be classified and numbered to prevent the varieties from being mixed. For some varieties, the peels should be washed in time, the seeds should be taken out and dried. Some should be threshed, impurities should be removed, dried, and then carefully selected, leaving the seeds with full grains and discarding the shrunken, broken and moldy seeds. Finally, the seeds should be placed in special seed bags or envelopes for storage. Generally, flower seeds are suitable for dry storage. Under dry, sealed and low-temperature conditions, their vitality can be maintained for a long time. Usually, the seed bags are stored in a refrigerator at 3-5℃, and the survival life of the seeds can be doubled. After the seeds of peony, peony, white magnolia, magnolia, and Michelia are harvested, the sand storage layering method should be adopted, that is, a layer of sand and a layer of seeds are arranged at intervals, and the sand soil should be kept moist so that the seeds can pass the after-ripening period and be stored in the sand until sowing in the next spring. The seeds of water lilies and jade lotus must be stored in water after harvest.

　　2. Lifespan of flower seeds

　　Understanding the lifespan of flower seeds is of great significance in the cultivation of flowers and the use, storage, collection and exchange of flower seeds. The environmental conditions that affect the lifespan of seeds are mainly humidity, temperature and gas. Generally, flower seeds can maintain their lifespan for a long time if they are fully dried and sealed in a bottle. Studies have shown that fully dried seeds can withstand extremely low temperatures as well as extremely high temperatures. Low temperatures can inhibit the respiration of seeds and extend their lifespan. Oxygen can promote the respiration of seeds, so excluding oxygen can extend the lifespan of seeds. There are physiological factors that affect the lifespan of seeds. One is the change in the properties of the seed coat, and the other is the decline in protoplasm vitality. Usually when fully dried, the seeds will be completely dried.

The lifespan of seeds collected after maturity is longer than that of seeds collected before they are fully mature. See the table for the lifespan of seeds of major flowers.

　　3. Pre-sowing treatment of flower seeds

　　Flower seeds must be treated before sowing. The purpose is to eliminate the pathogens they carry, to promote germination and growth, and to break dormancy and make them germinate early. There are roughly the following methods:

　　①Seed disinfection

　　You can soak it in 0.1% mercuric chloride or 0.3% copper sulfate solution, or 1% formalin solution for 5 minutes, then take it out and rinse it with sterile water before sowing.

　　②Soak seeds in cold or warm water

　　Seeds that are generally easier to germinate can be soaked in cold or warm water (35-40℃) before sowing. After the seed coat becomes soft, they can be taken out and sown.

　　③ File the seed coat

　　The seed coats of lotus, canna, oleander and poinciana are relatively hard and difficult to absorb water. You can use a file to grind or scratch the seed coat and then soak it in warm water for 24 hours. The seeds will absorb water and expand, which can accelerate their germination.

　　④Acid and alkali treatment

　　That is, the method of using acid, alkali and other agents to corrode the seed coat to promote germination. Treat the seeds with concentrated sulfuric acid for a few minutes to a few hours, and then rinse off the agent with clean water.

　　⑤ Chemical treatment

　　The seeds of morning glory and lathyrus can be soaked in 10-250 mg/L gibberellin solution before sowing, which can replace the effect of low temperature and promote their germination.

　　⑥Ultrasonic treatment

　　Ultrasonic treatment of Siberian iris and night-falling money can not only promote early germination of seeds and improve germination rate, but also accelerate the growth of seedlings.

　　⑦ Freezing or low temperature stratification method

　　It has a significant effect in promoting germination of flower seeds that require low temperature and humid conditions to complete their dormancy period, such as iris, Stachys, German gentian, delphinium, and primrose.

　　4. Sowing of flower seeds

　　The sowing period of open-field flowers is mainly in spring and autumn. Annual grass flowers have weak cold resistance, so they are usually sown after the late frost in spring. Open-field biennial flowers are cold-resistant flowers, and are generally sown in the cool autumn after the hot summer. Open-field biennial flowers are cold-resistant flowers, and are generally sown in the cool autumn after the hot summer. Due to the severe cold winter in the north, most types of biennial flowers need to overwinter in cold beds. The sowing period of perennial flowers varies depending on their cold resistance. Cold-resistant perennial flowers can be sown in spring, summer or autumn because of their strong cold resistance. Generally speaking, it is better to sow them as soon as the seeds are mature. The seeds of peony, iris, delphinium, etc. require low temperature and warmth to complete dormancy, and must be sown in autumn.

　　There are three main ways to sow flowers:

　　① Broadcasting method

　　The seeds are evenly spread on the soil surface. Because the amount of seeds sown is large, the number of seedlings produced is also large, and overcrowding can easily cause leggy growth and the occurrence of diseases and insect pests. This method is often used when sowing in pots.

　　②Drill sowing method

　　Seeds are sown in rows, with a certain distance between rows. Since there is a large space between rows and sufficient sunlight, the seedlings grow strong. However, in a certain area, the number of seedlings is not as large as that of broadcast sowing. This method is mostly used for sowing in shallow boxes and hotbeds. It can also be used when there are many varieties and the quantity of each variety is small.

　　③On-demand method

　　Also known as the hole sowing method, it is to sow seeds in holes according to a certain row and plant spacing. Generally, 2-4 seeds are sown in each hole. After germination, one healthy plant is left, and the rest can be moved to other places or removed. This method provides the most sufficient sunlight and air circulation, and the seedlings grow the strongest. This method can be divided into square, rectangular and triangular according to the row and plant spacing.

　　When sowing, the seedbed should be rich in humus, light and fertile soil or sandy loam, with sufficient sunlight, air circulation and good drainage. When preparing the land, the soil should be appropriately moist, and fully decomposed and finely crushed compost or manure should be applied as base fertilizer. When sowing, it is best to apply a moderate amount of superphosphate, which is conducive to the healthy growth of the root system. After the bed soil is leveled, it should be compacted because the soil is too loose. When sowing, large seeds can be sown one by one, and fine seeds can be mixed with fine sand before sowing. The thickness of the soil covering after sowing depends on the size of the seeds. Generally, large seeds are sown about 3 times the height of the seeds; small seeds are so covered that the seeds cannot be seen; the soil covering small seeds is best sieved with a sieve with a pore size of 0.3 cm.

After sowing, cover the bed with straw and spray water with a fine-hole watering can. Keep the soil moist.

　　5. Management after sowing flower seeds

　　After the seedlings emerge from the soil, the temperature, humidity and light must be properly controlled, which is the key to whether the seedlings can grow healthily. Poor air circulation, high temperature and humidity will make the seedlings grow thin and weak, and susceptible to damping-off. Control the water content and increase the light. For box sowing and pot sowing, the glass or plastic film should be opened gradually, first opening a gap, and then gradually removed to reduce the temperature and speed up air circulation. The seedlings of shade-loving flowers should also be exposed to light in the morning and evening, and shaded during the hot sun at noon. In short, the humidity should not be too high, the temperature should not be too high, the light should not be too weak, and pay attention to gradual training, and avoid sudden cold or heat, dryness or wetness.

　　Because the seeds are sown too densely during sowing (especially broadcasting), when the seedlings unfold their true leaves, the seedlings will crowd each other, competing for light and fertilizer, causing diseases, and need to be thinned out in time. All diseased seedlings and leggy seedlings that grow poorly should be removed as soon as they are found. Thinning needs to be done multiple times. The first time, follow a reasonable density, leave seedlings at equal distances, remove the overcrowded plants, and then combine it with transplanting. If the thinned seedlings are relatively strong and have 2-3 true leaves, they can be transplanted to the garden and pots for cultivation. The spacing between rows and plants for each thinning should be such that the true leaves are not connected. Be careful not to involve the remaining seedlings when thinning.

　　After thinning, the seedlings grow rapidly. When the true leaves are fully expanded, they should be transplanted in time. Before transplanting, keep the soil moist. When lifting the seedlings, pay attention to less root damage and keep as much mud as possible on the root system. Transplanted seedlings can be planted in gardens or pots. For transplanting in the open field, the land should be prepared in advance and light fertilizer should be applied once. For potted plants, clay pots should be selected, with one or two or three plants in each pot. When they grow up, they can be potted or divided. After planting, water thoroughly once to make the soil and seedling roots close. After transplanting, due to root injury, seedlings often wilt temporarily, and management needs to be strengthened to slow down the growth of seedlings in spring. Therefore, it is best to transplant seedlings on cloudy and windless days or in the evening. Avoid direct sunlight within a week. After the seedlings are alive, they can be managed normally.

　　meristem reproduction

　　1. Characteristics of flower division reproduction

　　Splicing is a method of using a part of a flower plant, such as a small plant, tiller or bulb sprouting from its rhizosphere, to split or cut it into several individual plants for planting. This is the simplest and most reliable method of propagation. It is easy to operate and has a high survival rate, but the reproduction rate is low and the production quantity is limited, which cannot meet the needs of large-scale cultivation.

　　According to the different biological characteristics of flower plants, division propagation can be divided into two categories: one is the plant division method, which is mostly used for flowering shrubs with strong clumping ability and perennial herbaceous flowers with strong sprouting ability; the other is the bulb division method, which is mostly used for bulbous flowers with corms and bulbs.

　　2. The period of flower division

　　The propagation of deciduous flowers should be done during the dormant period. In the south, it should be done after the leaves fall in autumn, when the air humidity is high and the soil is not frozen. Some flowers can grow some new roots before winter, and the branches are not easy to dry out in winter, which is also helpful to ease the labor tension in spring. In the north, due to the severe cold winter and dry winds, division after autumn is easy to cause the branches to freeze and dry out, affecting the survival rate. Therefore, it is best to divide the plants in the spring before the soil thaws and the plants have not yet sprouted.

　　Evergreen flowers do not have a distinct dormant period, but most of them stop growing and enter a dormant state during the growing season, whether in the south or the north. At this time, the sap flows slowly, so they are mostly divided before the vigorous growth in spring. In the north, most of them are divided before moving out of the greenhouse or immediately after leaving the room.

　　3. The process of flower division

　　The flower division method is to divide the small plants such as suckers, suckers, runners, runners and rhizomes that originate from the mother plant and plant them separately to form independent plants. Since these young plants have already developed more root systems, they are easy to survive after being divided.

　　Tillers: Most perennial flowers such as chrysanthemum, orchid, and daylily can produce many tillers at the base of the plant.

　　Runners: Most lawn plants, such as Bermuda grass, buffalo grass, and Zoysia, tend to produce runners from the mother plant, with young plants growing at each node and taking root at the bottom.

　　Runners: Plants such as Saxifraga and Chlorophytum often use runners for reproduction. Runners are thin and above-ground stems with long internodes, and young plants grow on the nodes.

　　Rhizomes: Plants such as zelan and aster have slender rhizomes (underground stems) with roots on the nodes to form young plants.

　　Sucker buds: such as aloe, tiger tail orchid, Echeveria, water tower flower, etc., their fleshy or semi-fleshy leaves are clustered on very short branches, and new roots grow out at the bottom close to the ground. When the new roots grow, they can be separated from the mother plant and planted.

　　Before dividing the flowers and trees that need to be planted, the mother plant cluster must be dug out from the field with more roots, and then the whole cluster must be split into several clusters with a sharp knife or an axe, each cluster has more roots. There are also some flowering shrubs and vines with strong sprouting ability, which often sprout many young clusters around the mother plant. When dividing the plants, it is not necessary to dig up the mother plant, but only dig up the tiller seedlings and plant them separately. Because some ramet seedlings and plants are young and have few roots, they need to be cultivated in the flower garden for one year before they can be planted.

　　The division propagation of potted flowers is mostly used for perennial grass flowers. Before division, remove the mother plant from the pot, shake off most of the soil, find out the extension direction of each tiller root system, and separate the clustered roots to minimize the damage to the root system. Then use a knife to separate the root neck connecting the tiller seedling and the mother plant, and immediately plant it in a pot. Some grass flowers such as Crinum and Agave can often breed young plants from the root neck. At this time, you can first dig the nearby pot soil, then use a knife to cut off the connection with the mother plant, and then use the young plant to take out the tiller seedling and plant it separately.

　　4. The process of flower bulb division

　　Most bulbous flowers have strong ability to divide in the underground part, and they can grow some new bulbs every year. Using them for reproduction is simple and can bloom early. The bulb division method must be treated differently because the plant organs of the bulb part are different.

　　Bulb division: For example, gladiolus, cyclamen and other bulbous plants. Gladiolus has a strong ability to divide. After flowering, when the old bulb dries up, it can divide into 1-3 large bulbs and several small bulbs. The large bulbs can bloom after being divided in the second year, and the small bulbs can bloom after 1-2 years of cultivation. The bulblets with a diameter of less than 0.5 cm can be sown in furrows and rows, which is the source of gladiolus for mass reproduction. The bulbs of cyclamen grow on the soil surface and rarely divide into small bulbs, so they are mostly propagated by sowing.

　　There are leather-scale sunflowers: such as daffodils, tulips, hyacinths and amaryllis, all of which have leather-scale bulbs. They are all autumn-planted bulbous flowers. Every year, several sub-bulbs are produced from the stem disk part of the base of the old bulb. They embrace the mother bulb, and these sub-bulbs are planted separately to cultivate large bulbs. Generally, it takes several years for them to bloom when they reach a diameter of 5-7 cm.

　　Barkless bulbs: Lilies and other plants have barkless bulbs. Each scale is quite large and loosely held together. When propagating, the scales can be peeled off and then inserted obliquely into the old potting soil. After rooting, 1-3 or more small bulbs can grow from the base of the old scales. They can be transplanted and propagated, and it will take 3-4 years for them to bloom.

　　Tuber division: For example, canna, etc., the underground part has horizontal tubers and many branches. When dividing the tubers for reproduction, each divided tuber branch must have a terminal bud in order to grow a new plant. After the division, no matter the size of the tuber, it can bloom in the same year.

　　Divide the root tubers: For example, dahlias have underground tubers, and their leaf buds are all attached to the root neck close to the surface, so each part must be divided with the root neck. When propagating, the whole tuber should be planted in the soil for germination, and then the foot buds should be taken for cutting propagation.

　　Divide the rhizomes: The underground parts of plants such as Calla Lily and Aspidistra are rhizomes. Most of them are perennial evergreen plants. The nodes of the rhizomes can form lateral buds, which can then grow new leaf clusters. You can cut the underground rhizomes of the leaf clusters, divide one plant into several plants, and plant them in pots together with the root system.

　　5. Management of flower division propagation

　　For woody flowers of the clump and sprout type, some decomposed fertilizer can be applied to the hole when transplanting. Usually, after watering the pots for division propagation, they should be placed in the shade or greenhouse for a period of time. If wilting occurs, water should be sprayed on the leaves and the surrounding area to increase the humidity. In Beijing, it is advisable to cut the stems or prune them short before winter and bury them in the soil to protect them from the cold during the winter. If transplanting before germination in spring, only appropriate pruning is required to allow normal germination and branching, but it is best to cut off all the flower buds to prevent flowering, so that the plants can resume growth as soon as possible.

　　For some perennial herbaceous flowers, bulbs, rhizomes, and root-stem flowers, a proper amount of basal fertilizer can be applied to the bottom of the hole when transplanting. The basal fertilizer should contain more phosphorus and potassium fertilizers. Water thoroughly and loosen the soil in time after planting to keep the soil appropriately moist. For the varieties transplanted in autumn, do not water too much. Increase the number of watering in the spring of the following year and apply thin liquid fertilizer.

　　Layering propagation

　　1. Characteristics of layering propagation and the appropriate period for its implementation

　　Layering propagation is to pile soil at the base of branches close to the ground or press the lower part of the base into the soil. For higher branches, high pressure method is used, that is, to surround the pressed part of the branch with moist soil or moss to provide environmental conditions for rooting. After rooting, it is cut off and planted to become an independent new plant. Layering propagation has a high survival rate and can be used for species that are difficult to propagate by other methods. It can also maintain the excellent characteristics of the original variety; the disadvantage is that the position is fixed and cannot be moved, and it is not easy to propagate in large quantities in a short period of time. Among flowers, this method is rarely used for one- or two-year-old herbaceous flowers, and only some flowers and trees use it.

　　Because layering is a method of propagation that does not separate the mother plant, the period for layering is relatively long. It can be carried out throughout the growing season, but it is mostly carried out in late April after the temperature warms up and stabilizes. It can be continued until July-August, so that there is sufficient time to form a complete root system before winter, so the seedlings grow quickly. Under the conditions of a medium or high temperature greenhouse, some potted flowers and trees can also be propagated by layering in winter.

　　2. The process of ordinary layering

　　Bend the branches at the bottom of the mother plant and press them into the soil to a depth of about 10-20 cm. If the pressed branches are elastic and difficult to hold down, you can use a thick lead wire to hook them and insert them into the soil, or add stones to the soil to hold them down. The branches pressed into the soil need to be cut or girdled with a knife. The branches should be exposed to the soil and exposed to light and dew. After the new roots grow well, they can be cut off and planted elsewhere.

　　The common layering method can be divided into three methods:

　　① Single branch layering method

　　Most woody flowers or some species of perennial herbaceous flowers can be propagated by this method. When layering, use one or two year old branches close to the ground as layering materials, bend the branches and press them into the soil.

　　②Continuous layering method

　　It is mostly used for shrubs and flowers. First dig a long longitudinal groove on one side of the mother plant, then slightly cut the nodes of the branches close to the ground, and then bury them shallowly in the soil groove, with the tips of the branches exposed to the ground. After a period of time, the nodes buried in the soil can sprout new roots, and soon the axillary buds on the nodes will also sprout and push out of the soil surface. When the newly sprouted seedlings mature, use a sharp knife to penetrate the soil layer to cut off the internodes of each section. After more than half a year of cultivation, the seedlings can be transplanted.

　　③Wave layering method

　　For some flowers and trees with long branches that are easy to bend, such as wisteria, trumpet creeper, honeysuckle, etc., you can bend the long branches and pull them to the ground, and make cuts on multiple nodes, with the cuts at least 30 cm apart. Then fix the cut parts and bury them in the soil. After they take root and branch out, cut them off from the mother plant and plant them separately.

　　3. The process of soil layering

　　The soil layering method is also called the pile layering method. It is suitable for clumping flowers and trees with many root tillers, such as pomegranate, campanula, rose, crabapple, magnolia, hydrangea, gardenia, azalea, peony, pearl bush, etc. Make a wound at the base of the branch, then pile up the soil, and transplant them separately after they take root.

　　Because the pressed branches do not need to be bent and buried in the soil, the soil-covering propagation is more suitable for species whose branches are not easy to bend. It is carried out in the peak growth season in early summer. The lower part of the branches is ring-cut 20-30 cm from the ground, and then the base is piled up in a trowel-like shape to cover the lower half of the entire plant cluster. The soil pile should be kept moist. After a period of time, the hidden buds in the wound after ring cutting will regenerate and grow new roots. In the early spring of the following year, the soil pile is dug up again, and the new roots are cut one by one from the bottom. After the seedlings are separated, they are moved to the nursery and cultivated for another year, or directly used for planting.

　　4. The process of high branch layering

　　High branch layering is also called aerial layering. It is mostly used for plants that are relatively upright, have hard branches that are not easy to bend, and are not easy to sprout. This method is also often used for some flowers and trees that are not easy to root by cuttings. A considerable number of them are precious flowers and trees, such as white orchid, camellia, bougainvillea, dracaena, magnolia, cordyline, croton, osmanthus, plum, Milan, Michelia, and Indian rubber tree. Most of the branches of high branch layering should not exceed 1/3 of the mother plant branches, and the highest should not exceed 1/2, otherwise it will affect the normal growth and development of the mother plant.

　　For high-pressure branches, choose healthy branches. Use a sharp knife to cut twice about 5 cm above the branch, deep into the cambium, remove the bark between the two cuts, and the ring cutting is completed. The width of the ring cutting is 1-2 cm. The cortex must be removed after ring cutting, otherwise the ring cutting area is often filled with callus tissue and will not take root. After ring cutting, use leaf mold, dry moss, etc. to wrap the ring stripping area into a mud ball. In order to prevent rain erosion, bamboo tubes or flower pots should be covered on the outside. Plastic film is often used now, which makes it easy to obtain materials and simple to operate. Generally, it is wrapped with mud balls after ring cutting, and some are wrapped with mud balls after callus tissue grows. Keep the mud balls moist, and they will take root in about 2-3 months. When there are more roots, you can cut it with mud balls, remove the wrapping, and plant it in a flower pot with mud balls for maintenance.

　　5. Management after flower layering

　　The time to cut off the layering strips from the mother plant after rooting can be determined according to their growth speed. Some species such as plum blossoms and wintersweets grow slowly and need to be cut off in the next year; while some species such as roses and honeysuckle grow quickly and can be cut off in the same year. When transplanting, bring as much soil as possible to protect the new roots.

　　During layering, since the plant does not separate from the mother plant, the water and nutrient supply is not a big problem. However, after separation, there will inevitably be a process of transformation, adaptation, and independence. Therefore, after separation, it should be placed in a shaded environment first, and avoid exposure to the sun, and then gradually increase the light. For newly separated plants, some branches and leaves should also be cut off to reduce transpiration, maintain water balance, and facilitate survival. Pay attention to water supply after transplanting. When the air is dry, pay attention to spraying water on the leaves and indoor watering, and pay attention to keeping the soil moist. Apply fertilizer appropriately to ensure growth needs.

　　Cutting propagation

　　1. Selection of cutting propagation period

　　The most suitable period for cutting propagation depends on the type, variety, climate management method of the flowers. It is usually divided into two categories: soft branch cuttings during the growth period and hard branch cuttings during the dormant period. Because it is easy to obtain materials, has a large number of reproductions, quickly matures, blooms early, and can maintain the excellent characteristics of the original variety, it is widely used in production.

　　Cuttings during the growing season: It is to use semi-hard branches or tender branches of some woody and herbaceous flowers as cuttings for cuttings. Most woody flowers generally have semi-hard branch cuttings after the first growth of new branches of the year ends, or about one month after flowering, about May-June. Herbaceous flowers have a strong adaptability to cutting propagation, and most of them can be cut in spring, summer, autumn and other seasons.

　　Dormant cuttings: For some deciduous woody flowers, hard branch cuttings should be taken when the plant branches have the most nutrients accumulated, which should be done from November to February or March of the following year after entering dormancy in autumn and winter or before germination in spring. If cuttings are taken in a greenhouse to accelerate propagation, the cuttings should be placed in a low temperature of about 5°C for 20-30 days before cutting, which will help them germinate through physiological dormancy. If dormancy is not broken, the cuttings will take root but will also germinate easily.

　　Greenhouse flowers can maintain their growth all year round under the conditions of greenhouse growth, so both herbaceous and woody flowers can be propagated by cuttings at any time in the four seasons. However, in terms of their growth habits, spring is the best, followed by autumn, summer and winter. Of course, as long as all conditions and measures are met, ideal results can be achieved.

　　2. Cutting propagation method

　　The method of cutting propagation depends on the different cutting materials, which can generally be divided into several categories such as branch cuttings, leaf cuttings, bud cuttings and root cuttings.

　　① Branch cutting

　　The branches of flower plants are used as cuttings. Usually, according to the age of the branches, there are two types of cuttings: softwood cuttings and hardwood cuttings:

　　Softwood cuttings: also known as soft branch cuttings and green branch cuttings. Due to its strong vitality, as long as the conditions are right, it can quickly take root and sprout and grow into a new plant. Generally, strong and nearly mature branches are cut, with or without stem tips. 2-3 nodes are a cutting, about 10 cm long. Cut off the lower 1/3 of the leaves of the cuttings, and keep the upper leaves. If the leaves are too large, you can also cut off 1/4-2/3 of each leaf. The incision at the bottom of the cutting should be close to the lower part of the node, and the incision needs to be flattened with a sharp knife to facilitate wound healing and rooting. Chrysanthemum, carnation, begonia, and red safflower can all be used for softwood cuttings.

　　Hardwood cuttings: Use mature and lignified stems or branches as cuttings for cuttings. Select mature, short and sturdy one-year-old branches, cut into cuttings about 10 cm long and about 3-4 nodes. It is usually done during the dormant period from leaf fall to budding next year. Autumn cuttings are more common in the south; spring cuttings are more common in the north; winter cuttings are best in tropical and subtropical areas of South China; Rosaceae and other vines that are easy to root can also be cut in the rainy season. Various species of kiwano, cordyline, monstera, hand tree, golden plate, croton, rubber tree, etc. are propagated by hardwood cuttings.

　　② Leaf cuttings

　　It is to use the leaves of flowers as cutting materials to propagate plants. It is often used for some perennial herbaceous flowers, especially some species with thick leaves and strong petioles and veins, and adventitious teeth and adventitious roots are easy to occur on the leaves. It can also be propagated by 4 different cutting methods.

　　Flat laying method: For example, for begonias, first cut off the petiole, then lay the leaves flat on the sand, fix them with iron or bamboo needles, and make their bottom close to the sand surface. Young plants will grow from the leaf veins or the base of the leaves.

　　Direct insertion method: This method is used for cuttings of species such as Gloxinia, Tiger Piranha, Northern Violet, Chrysanthemum, Gesneria, etc. The petiole is directly inserted into the sand. After a period of time, fibrous roots will appear at the base wound and underground rhizomes will grow, and the terminal buds will grow into new plants.

　　Petiole insertion: Soak the leaves and petioles of the rubber tree in water. New roots will grow from the wound at the base of the petiole. Then make a cut at the connection between the leaves and petiole and plant in sandy soil. After about 3 months, new seedlings will grow from the root zone.

　　Scale cuttings: If you peel lily scales for cuttings, after the bulbs are harvested, dry them for a few days, then peel off the scales and insert them in the bed. After about 6-8 weeks, small bulbs will grow from the base of the scales.

　　③ Bud cuttings

　　In order to save propagation materials and obtain more plants in a short period of time, this method can be used. This is to take advantage of the strong regeneration ability of axillary buds of some flowers. Chrysanthemums, geraniums, hydrangeas, etc. can all be used for bud grafting.

　　④ Root cutting

　　Suitable for species that easily produce new shoots from the roots, such as peony and trumpet creeper. You can select thick roots, cut them into 5-10 cm sections, and insert them all into the bed. For perennial flowers with small fleshy roots such as spathiphyllum and perennial phlox, you can cut the roots into 2-5 cm sections, spread them on the sand surface of a shallow box or large flower pot, and then cover them with 1 cm of sand or fine loose soil, and keep them moist.

　　3. Operation of cutting propagation

　　The equipment for cutting propagation can be selected according to the scale and requirements. When propagating in large quantities, it is advisable to carry out the propagation in a greenhouse so as to adjust the room temperature and facilitate the survival of the cuttings. The cutting bed is generally about 70-80 cm high, about 100 cm wide, and about 20-30 cm deep. It faces the glass window or plastic film, and drainage holes must be set at the bottom of the bed. The cutting box is a more ideal cutting equipment. There are many types. Generally, there is a glass cover to maintain air humidity and an automatic temperature controller. The open-air cutting bed is the most widely used. It is advisable to choose sandy and well-drained soil, preferably semi-shaded. For small-scale propagation, shallow pots, shallow boxes or ordinary flower pots are used.

　　The cutting medium requires ventilation, easy to keep moist and good drainage. Commonly used are river sand, peat, vermiculite, perlite, etc. River sand is the most widely used, and coarse quartz sand without organic matter is the best. It has good ventilation and drainage, but weak water retention. Peat has strong water retention and can remain moist for a long time. Its equal mixture with river sand is the most ideal for cuttings of most flowers. Vermiculite has a strong ability to retain water and nutrients. Perlite has more pores than vermiculite, so its water retention is relatively poor. Other cutting media include sphagnum moss, humus, clay, charcoal powder, brick chips, coal slag, coconut fiber, etc.

　　When propagating by cuttings, you must first select the cuttings. No matter which method is used for cuttings, you must choose a part with vigorous growth and no diseases and insect pests, which is conducive to rooting, survival, and cultivating excellent seedlings. When cutting branches, cut the selected branches into cuttings that are 10-15 cm long and have 3-4 nodes. The lower end should be cut flat near the node, because the meristem in this part is active and easy to root. The upper end should be cut into a 45-50 degree slope 1 cm above the top bud to prevent water accumulation on the top and cause rot. For cuttings during the growing season, especially leaf cuttings, cuttings should be cut before cutting. For roses, hibiscus, trumpet creepers, etc., cuttings can be made in a closed plastic shed, or the cuttings can be tied into bundles and buried in the soil or used.

Wet sand is buried in the flower pot, placed in a place of 0-5℃ (if the amount is small, it can also be wrapped with plastic film and placed in a refrigerator at 5℃), and then cut in the early spring of the next year. For herbaceous flower cuttings such as hydrangeas that contain more water, dip the bottom of the cuttings in some plant ash before cutting to prevent rot after cutting. For some varieties such as lilac and roses that are difficult to root, dip the bottom of the cuttings in rooting agents before cutting, which has a significant effect on promoting rooting.

　　4. Management during cutting propagation

　　In order to promote the rooting of the cuttings as soon as possible after cuttings, it is necessary to strengthen the management of the cuttings after cuttings, which mainly involves maintaining suitable temperature, humidity, light and air conditions in the cutting bed.

　　Temperature conditions play an important role in rooting of cuttings. The suitable rooting temperature for most soft-branch cuttings of flowers is 20-25℃; the suitable temperature for semi-hard-branch and hard-branch cuttings is 22-28℃; the suitable temperature for leaf cuttings and bud cuttings varies according to the species, and the suitable temperature is within the range of 20-28℃. If the cuttings have a device to increase the bottom temperature, it is beneficial for hard-branch cuttings in early spring. If the temperature of the cutting bed is lower than 20℃, the cuttings are not easy to root; if it is higher than 28℃, the cuttings will easily wilt and affect rooting. For this reason, we should try to maintain a suitable temperature, especially in summer to prevent high temperature damage, open the cover, and spray the leaves to cool down.

　　Temperature is also an important condition for the survival of cuttings. The substrate is required to continuously provide sufficient moisture to keep the branches and leaves fresh, to facilitate the formation of callus tissue of the cuttings, and finally to produce the root system. Generally, 50%-60% of soil moisture is appropriate. Too much moisture often causes the cuttings to rot. In order to avoid excessive evaporation of the cuttings and leaves, the cutting bed is required to maintain a high air humidity, usually 80%-90% relative humidity. For this purpose, leaf spraying and adjusting the covering should be used in time to control it.

　　Light is also an important condition for the rooting and survival of cuttings. The terminal buds and leaves of the cuttings can only photosynthesize under sunlight and produce auxins to promote rooting. However, since they have been separated from the mother plant, they should be properly shaded. Generally, 70% of the shade is appropriate. After rooting, the light can be gradually increased to facilitate growth.

　　Oxygen is also necessary for rooting of cuttings. Therefore, in addition to a loose matrix, attention should also be paid to ventilation of the cutting bed.

　　5. The process of flower water propagation

　　The water-cutting propagation of flowers requires simple conditions and easy operation. Some flowers suitable for water-cutting propagation, such as crabapple, impatiens, oleander, rose, camellia, azalea, hibiscus, gardenia, trumpet creeper, white orchid, magnolia, pomegranate, carnation, lucky bamboo, dahlia, etc., can use water as the substrate, soak the cuttings, and propagate by rooting.

　　For water cutting propagation, semi-lignified branches should be selected for woody flowers, and mature and strong branches should be selected for herbaceous flowers. Cut the strong and sturdy branches of the current year or two years old into 6-10 cm long cuttings, leave 2-5 leaves on the upper part, and use a knife to cut the lower end of the branch into a horseshoe shape. Soak in 0.1% potassium permanganate solution for 6-24 hours before inserting. You can also use a mixture of 100 mg/L indolebutyric acid and 100 mg/L naphthaleneacetic acid to soak the base for 6-24 hours, or use 1000 mg/L indolebutyric acid to quickly soak for 3-5 seconds, then insert it into a glass bottle, change the water every 1-2 days, and place it in a culture room at 20-25℃. It will take root in about 10-30 days. When the root system is fully developed, the rooted cuttings can be taken out and potted, and then placed in a shaded place

This method is particularly suitable for herbaceous flowers, which can greatly reduce the rot phenomenon in sandy soil cuttings and increase the rooting rate.

　　Grafting

　　1. Selection and cultivation of rootstock

　　The selection of rootstock is very important in grafting propagation. The rootstock should be selected with close affinity to the scion and with strong affinity. If the relationship between the rootstock and the scion is distant or the affinity is poor, even if the graft survives, it is easy to break due to incompatibility at the interface. Therefore, the correct selection of rootstock is not only easy to heal, but also can improve the adaptability of the grafted seedlings, prolong life or bloom early. The rootstock must be selected with strong resistance, strong growth, and adaptability to the woodland environment.

　　The cultivation of rootstock seedlings usually uses the sowing method, not only because the seedlings have strong resistance to adverse external environmental conditions and long lifespan, but also because of their young age, it is impossible to change the inherent characteristics of the scion of excellent varieties. The diameter of the main branches of the seedlings used as rootstocks should be thicker than the scion and fully lignified, so most of them need to be cultivated in the nursery for more than 2 years. After sowing, the seedlings need to be transplanted or potted. The time for transplanting is in the autumn of the sowing year or the early spring of the following year. The purpose of doing this is, on the one hand, to cut off the main root of the rootstock and promote the development of its lateral roots or fibrous roots to increase the absorption area of ​​the root system; on the other hand, to increase the spacing between plants and rows, which is convenient for manual operation during grafting and for lifting the seedlings with soil balls in the future. The rootstock seedlings should also be pruned to remove the overly dense side branches for easy grafting.

　　2. Grafting operation

　　Branch grafting is a grafting method that uses branches of flowers and trees as scions. It is usually done during the dormant period, and only close grafting is done during the growth period. It can be divided into the following types:

　　① Cutting method

　　It is mostly used for open-field woody flowers such as plum blossoms and peach blossoms. It is often carried out in spring when the terminal buds have just sprouted and the branch shoots have not yet grown. At this time, the sap in the branches has begun to flow, the interface is easy to heal, and the survival rate of the graft is high. It is better to choose one-year-old branches as scions. The scion is 5-7 cm long, with 2-3 buds left on each section, and the lower end is cut into an inclined surface. The rootstock is cut 5 cm above the ground, and then cut longitudinally. The size of the incision is similar to that of the scion. Then align the cambium of the scion and the rootstock and tie it tightly to prevent rain from entering.

　　② Cleft grafting

　　Also known as the cut grafting method, it is mostly used for grafting thicker rootstocks or flowering trees. First, cut off the upper part of the rootstock about 10 cm above the ground, and then cut a 3-5 cm deep incision vertically in the center of the cross section of the rootstock. The scion is selected from the full bud segment, leaving 2-4 buds as a scion, about 5-10 cm long; the base is cut into a wedge shape on both sides, inserted into the incision of the rootstock, and the cambium is aligned, and then tied tightly with a film strip.

　　③Connection method

　　It is often used for some flowers and trees that are difficult to root by cuttings and difficult to survive by other grafting methods. For flowers and trees propagated by grafting, the mother plant should be planted next to the rootstock, or in the same flowerpot. The rootstock can also be hung on the scion mother tree or placed next to it. Cut off a part of the rootstock and scion, and the wound surface cambium is close to each other, and then tied with plastic film. After the grafting is alive, cut off the scion under the interface, and cut off the upper rootstock in batches to form an independent plant. Generally, the crown of the scion mother tree is required to be larger and the crown of the rootstock is smaller. It is also possible to graft 4-5 branches at a time.

　　④ Softwood grafting

　　The technique is the same as the cleft grafting method, except that the rootstock and scion are made of young branches of the current year.

　The grafting should be carried out in June and June, which is conducive to the later growth, development and maturity of the grafted seedlings and easy to overwinter. The rootstock should be selected from the strong branches grown in the current year, and the scion should be selected from the strong young branches sprouted in the current year. The grafting technology refers to the cleft grafting method.

　　⑤Root connection

　　It is a grafting method that uses roots as stock. It is commonly used for peony, rose, magnolia, trumpet creeper, hibiscus, wisteria, etc. It is mostly carried out during the dormant period in winter or early spring. Generally, the roots of 1-2 year old seedlings are used as stock, and the root thickness is 1-1.5 cm. At 4-5 cm from the thicker end of the root, a smooth and round part is selected, and a small inclined cut is made. The inclined surface is about 30 degrees with the longitudinal axis of the root, and the depth of the cut is about 1/3-1/2 of the thickness of the connected part. After the root is cut, the scion is inserted into the root so that the cambium of both sides are closely connected, and then tied with plastic film strips, and the interface is buried with wet sand.

　　3. Bud grafting operation

　　Bud grafting saves scion materials, is simple, has a high survival rate, and a long grafting time. It can check the survival status early, and can be re-grafted if it does not survive. The flowers and trees used for tooth grafting must be easy to peel off the cortex and wood. Bud grafting is mostly carried out in mid-to-late August in the north and in early September in various parts of the south. It can be divided into the following types.

　　① "T" budding

　　It is also called shield bud grafting because the rootstock is cut in a "T" shape and the bud piece is shield-shaped. This method is the most widely used. During the operation, the grafted bud is cut into a shield-shaped bud piece of about 2 cm with the bud as the center. When cutting the bud, the wood should be cut. Then choose a smooth part on the rootstock and cut it into a "T"-shaped interface, and the wood should also be cut. Then pry open the bark and insert the cut bud piece tightly. The upper part of the bud piece should be in close contact with the cut horizontal knife, and then tie it tightly with a plastic film strip. About 1 week after grafting, if the petiole falls off, it means that it has survived, and if it does not fall off, it means that it has not survived. The binding material can be removed 2-3 weeks after grafting. After survival, the buds will not sprout in the same year. The rootstock can be cut off 10 cm above the interface, and the grafted buds can be planted facing south. Pay attention to removing the rootstock's suckers in the next spring.

　　② Intercalation of buds

　　When the stock and scion are not much different in thickness (at most twice as large), bud grafting is appropriate, also known as scarf grafting. No peeling is required, the operation is simple, the survival rate is high, and the growth and development are good. The cut of the bud is roughly the same as that of the stock, both of which are inverted shield shape. The lower end of the bud is embedded in the wood of the lower end of the stock, and the interface is tightly fitted. The other methods are basically the same as the shaped bud grafting.

　　③Bud tube socketing

　　Also known as tube bud grafting and bud grafting, it is easy to operate and has a high survival rate. The grafted bud is cut with a width of 1.5-2 cm with the bud as the center. Cut the branch bark with a knife on the upper and lower rings, and then cut a knife on the back of the bud longitudinally, and gently remove the bud tube. Cut the rootstock with a knife, cut it longitudinally several times, and peel the bark downwards, the length is equal to the tube bud. If the rootstock is thicker than the bud tube, leave a part of the rootstock unpeeled, then cover the bud, cover the rootstock bark, and tie the upper and lower ends of the bud tube with cotton thread. In the early stage of grafting, the interface should be protected from light, and it should be wrapped with opaque plastic tape to block light, which is conducive to callus survival. Avoid exposure to the sun in the early stage of survival, and do a good job of watering and other management. When cutting the rootstock, apply wax on the fracture to prevent rot.

　　4. Factors affecting graft survival

　　The factors affecting grafting survival are mainly the affinity between rootstock and scion, the internal conditions of rootstock and scion, the environmental conditions during grafting and the grafting technology.

　　In terms of the affinity between the rootstock and the scion, the graft survival rate is high if the rootstock and the scion are of the same species or genus in plant taxonomy, while it is difficult for different species or genera to survive, and even if they survive, they will grow poorly in the future. In flower grafting, single-petal plants of the same species are often used as rootstocks, and double-petal plants are used as scions, which takes into account the affinity between the rootstock and the scion.

　　The development and robustness of the rootstock and scion and the amount of nutrients they store and accumulate are also very important. Therefore, the rootstock and scion must be selected very strictly during grafting. Only when the rootstock and scion contain sufficient nutrients can the differentiation of the cambium be promoted, the formation of callus tissue can be promoted, and the grafting survival rate will be high. If the tissues of either the rootstock or the scion are not full and well developed, the success of the grafting will be affected.

　　The scion should be taken from the sunny side of a healthy plant. It should be one-year-old or current-year branches with full growth and short internodes. The survival rate of branches over two years old is low. The scion of evergreen species is generally grafted immediately after being harvested, and there is no need to store it. The rootstock is required to be in the vigorous growth period or after the sap begins to flow when grafted. In this way, after grafting, during the healing of the scion and the rootstock, and the growth of the scion bud, the rootstock can obtain sufficient nutrients and water supply, which is beneficial to improve the survival rate.

　　From the perspective of environmental conditions, the most suitable temperature for grafting is 20℃. Temperatures below 15℃ or above 30℃ will affect the healthy growth of callus tissue. Therefore, when the temperature is low in spring, plastic film or bagging should be used for insulation. It is necessary to maintain high humidity after grafting. Generally, flowers and trees need to maintain a temperature above 90%. To this end, strong light should be avoided to reduce leaf evaporation. Plastic tape should also be tied to the grafted area to keep it moist. Generally, dark conditions can promote wound healing.

　　5. Management after grafting

　　To promote the healing of the interface, the interface should be kept at a high relative humidity. In addition to wrapping the interface with plastic film strips to keep it moist, the interface can also be covered with fine soil, especially for dormant grafting. Plastic bags or small plastic sheds should also be placed over the grafted area to maintain relative humidity, increase soil temperature, and promote healing. The covering should be removed after the temperature rises to prevent the buds from not being able to see the light in time or from being yellow and weak due to insufficient light. Binding materials should also be removed in time to avoid affecting the normal growth of the rootstock and scion.

　　After the bud grafting is successful, the top of the rootstock can be cut off before it sprouts in the early spring of the following year. The scion buds can grow into seedlings in the same year. The binding materials can be removed in the autumn of the same year when the plants are grafted. If the interface has healed, the scion can be cut off from the mother plant from the bottom of the interface to become a new seedling; if the grafting does not survive, the rootstock and scion should be separated and grafted again next year. The new shoots that emerge after the grafting survives should be protected by a support in the first year, especially in the windy season, the support can prevent the break between the scion and the rootstock. Pay attention to the water and fertilizer management of the grafted seedlings, not too dry or too wet, it is better to keep it moist. The suckers that emerge from the rootstock should be cut off in time.

Tissue culture technology　

　　1. Application value of flower tissue culture

　　Flower tissue culture is to separate parts of flower plants, such as stems, stem segments, leaves, flowers, young embryos, etc., in sterile test tubes, and combine certain nutrition, hormones, temperature, light and other conditions to produce complete plants. Because its conditions can be strictly controlled, it grows rapidly, and a cycle is 1-2 months, so it has important application value in the production of flower plants.

　　Rapid mass propagation: It is widely used for some rare and difficult-to-propagate flowers and some flowers that need to be produced in large quantities in a short period of time. Orchids, chrysanthemums, gladiolus and other flowers use axillary buds to proliferate and obtain a large number of plants in a short period of time. African violets can be induced to produce adventitious buds through leaves, and daffodils can be induced to produce adventitious buds through ground scales to achieve the purpose of mass propagation.

　　In flower breeding: many flowers such as lily and iris can be used for distant hybridization. However, due to physiological and metabolic reasons, hybrid embryos often fail early, and thus no hybrid plants can be obtained. Embryo culture in a test tube can make them grow smoothly and obtain distant hybrids. In addition, callus mutagenesis, pollen culture and other methods can be used for flower breeding.

　　In terms of cultivating virus-free seedlings: a large number of flowers such as chrysanthemums, gladiolus, daffodils, tulips, dahlias, etc. are propagated by asexual reproduction, and viruses are passed on and accumulated from generation to generation, causing increasingly serious damage. By isolating the growth points of flower plants with a size of 0.1-0.5 mm, the seedlings obtained are basically virus-free. Therefore, this technology has been widely used in the cultivation of virus-free seedlings of flowers.

　　2. Requirements for laboratories and equipment for flower tissue culture

　　Flower tissue culture is the cultivation of flowers under artificially controlled conditions. It is a new technology for modern factory production of flowers, so it has certain requirements for laboratories and equipment.

　　Laboratory

　　① Chemical laboratory: mainly responsible for the preparation of culture medium. It is required to have various chemical reagents, various glassware, weighing scales, etc.

　　② Washing room: Mainly used for washing glassware. It requires running water and an oven for drying after washing.

　　③ Sterilization room: mainly used for sterilizing culture medium and equipment. It must have a high pressure sterilizer, water source and power supply.

　　④ Inoculation room: It is the place for flower material separation, sterilization, inoculation and transfer. It should be airtight, clean, neat, equipped with ultraviolet light, and capable of sterilization at any time. In some cases, it can also be replaced by an inoculation box or a clean bench.

　　⑤ Cultivation room: It is the place where flower materials are cultivated and grown. It should be clean, well-insulated, with uniform room temperature, and have heat insulation and fireproof properties.

　　Equipment

　　① Balance: used to weigh drugs and hormones when preparing culture medium. Use ordinary balance for macroelements and analytical balance for trace elements and hormones.

　　② Acidity meter: used to measure the pH of the culture medium.

　　③High pressure sterilizer: used for sterilizing culture medium and instruments.

　　④ Oven: used for drying and sterilizing clean glassware.

　　⑤Distilled water production device: obtain pure water for culture.

　　⑥Refrigerator: for storing mother liquor and plant materials.

　　⑦ Inoculation box or clean workbench: the place for inoculation or transfer of plant materials.

　　⑧Air conditioner: used to control room temperature.

　　3. Requirements for culture medium for flower tissue culture

　　Culture medium is a very important matrix in flower plant tissue culture. There are many kinds of culture medium currently in use, but their main components are generally the same. The main component is water, and others include macroelements, trace elements, vitamins, growth regulators, sucrose and agar.

　　At present, the most widely used medium in flower tissue culture is MS medium. Its composition is to add 1.65g ammonium nitrate, 1.9g potassium nitrate, 0.44g calcium chloride, 0.37g magnesium sulfate, 0.17g potassium dihydrogen phosphate, 0.83mg potassium iodide, 5.2mg boric acid, 22.3mg magnesium sulfate, 3.6mg zinc sulfate, 0.25mg sodium molybdate, 0.025mg copper sulfate, 0.025mg cobalt chloride, 27.8mg iron sulfate, 30g sucrose and 7g agar when preparing 1L (1000ml) medium. Other growth regulators should be determined according to the type of flowers and the purpose of cultivation. The concentration of macroelements in MS medium is too high, so 1/2 or 1/4 of the concentration of macroelements is often used for cultivation, so that the growth effect is good.

　　Before preparing the culture medium, you need to prepare glassware such as Erlenmeyer flasks, test tubes, beakers, measuring cylinders, and pipettes, and weigh the medicines in advance. When preparing, first dissolve the agar, then add various nutrients and sucrose dissolved in water, and then use sodium hydroxide or hydrochloric acid to adjust the pH of the culture medium, generally around 5.7. Later, you can dispense it into the culture bottle and cover it. The culture medium should be sterilized by high pressure. After cooling, put it in the culture room for pre-culture for 3 days. If there is no contamination by miscellaneous bacteria, you can inoculate the flower materials.

　　4. The process of flower tissue culture

　　Flower plant tissue culture is sterile culture, which means that the cultured materials are free of bacteria. When cutting flower materials from fields or greenhouses, you should choose healthy and disease-free mother plants, and take young and tender parts with strong reproductive ability to facilitate growth.

　　Although the materials have been selected, there are always many bacteria on the outside. For this reason, surface sterilization should be performed before inoculation. Usually, rinse with tap water for more than ten minutes, and the mud should be brushed off. After rinsing, soak in 70% alcohol for 10-15 seconds for disinfection. Then rinse twice with sterile water (autoclaved distilled water), then soak in 10% bleach clarified solution for 20 minutes for disinfection, and finally rinse with sterile water 3-4 times. Materials with hair that are not easy to wet and disinfect can be added with some washing powder. The above operations should all be performed in sterile environmental conditions such as inoculation boxes or ultra-clean workbenches. For materials that have been surface sterilized, use sterile filter paper to absorb the water. Then use a scalpel to cut the required part, usually a few millimeters in size, and less than 1 mm for cultivating virus-free seedlings, and then use a dissecting needle or gun-type tweezers to inoculate the material into the culture bottle for culture. After using the tools, dip them in 95% alcohol or disinfect them with flame disinfection to avoid cross contamination caused by bacteria in the tools. When operating, you should wear work clothes and work hat, wash your hands in advance, and then wipe them with alcohol cotton.

　　5. Cultivation and transplantation of flower tissue culture materials

　　After the flower materials are inoculated, they are placed in the culture room for cultivation. The culture room is the place where flower materials are cultivated and grown, generally ranging from a few to more than ten square meters. The height is about 2 meters, the space is small, and the temperature control energy can be saved. The culture materials are placed on the culture rack for cultivation. The culture rack can be made of wood or metal, with 4-5 layers, each layer is 40-50 cm high, and the fluorescent lamp is installed on the top. The rack is about 1.2 meters long, the same as the length of a 40-watt fluorescent lamp, and 80-90 cm wide. Two fluorescent lamps can be installed on each layer, so the illumination during cultivation is about 3000 lux. The temperature of the culture room is mostly maintained at a constant temperature day and night, maintained at 25℃±2℃, and there are also day and night variable temperature cultivation. The temperature at night can be lower, which should be determined according to the growth needs of flowers. Fluorescent lamps are illuminated for 12-16 hours a day.

　　Flower test tube seedlings generally grow well and have many roots because of artificially provided superior conditions in all aspects. However, due to the lack of understanding of their characteristics, the survival rate is not high when transplanted. This is because the test tube seedlings are cultured under high humidity conditions in the bottle, and carbon sources such as sucrose are artificially provided. The flower materials are in a heterotrophic state, which can be said to be much more delicate than flowers grown in a greenhouse. And suddenly moving them from the bottle to the soil to let them live an autotrophic life often causes damage or even death due to too drastic changes. For this reason, when the flower test tube seedlings are first moved out, they should still be covered with glass bottles or film bags (with a few small holes on them), and removed after 1 week. Spraying conditions are more ideal. Shade for the first 7-10 days, and then gradually see the sun. The transplanting substrate is preferably half sand and half vermiculite, with good drainage and ventilation, and nutrient solution is poured every other day. In this way, they are gradually trained to adapt to the environment. After 2-3 weeks, the acclimated and trained seedlings can be moved to the culture soil for planting.