Phalaenopsis is a orchid orchid phalaenopsis flower, mainly distributed in tropical areas, only a very small number of species can be distributed in the subtropical region of western China, so far 46 species have been found. Phalaenopsis is a single stem type aerial orchid, with succulent leaves, shortened stems, aerial roots and infinite racemes, like high temperature environment. Phalaenopsis orchids are arranged neatly, beautifully, with a large number of flowers, a long flowering period, and a wide variety of colors. They can be supplied throughout the year and are loved by domestic and foreign consumers. They are called "after orchids." Phalaenopsis can be used both as a potted plant and a cut flower. It is a popular potted orchid that accounts for about 30% of the total sales of potted orchids in the world. Taiwan is the main production and export place of the world Phalaenopsis. In recent years, under the investment and drive of Taiwanese businessmen, the development of the orchids in the Chinese mainland has also been very rapid, and the planting area has increased rapidly. This year, a new wave of planting booms has started, and there has been a serious shortage of seedlings. It can be predicted that for a long time to come, the Phalaenopsis is still the main species in China. Phalaenopsis flowering time, flowering quality, flowering duration, and storage and transportation resistance are important factors affecting its commodity value, and are also issues of great concern in production and research. In this paper, combining with the flowering physiology of Phalaenopsis, the main points of flowering management are introduced. Influencing Factors of Flowering of Phalaenopsis Infant: Juvenile is the stage of early plant growth during which no treatment can induce flowering. Phalaenopsis also requires vegetative growth over a period of time before it can accept environmental stimuli and pull stems to bloom. Whether or not Phalaenopsis has passed through the juvenile period is highly positively related to the leaf area. The larger the leaf area, the higher the sapling rate and the better the flowering quality. In general, Phalaenopsis seedlings grow 15 to 17 months after the bottle is grown, and when the leaf area reaches 300 to 500 square centimeters, they enter the mature stage, and they can induce low temperatures and stems to blossom. Environmental factors: including temperature, light and moisture, and temperature and light are the main environmental factors that regulate the stem and flowering of Phalaenopsis. temperature. By regulating the temperature of the Phalaenopsis cultivation environment, flowering can be promoted or suppressed, and various production and market demands can be satisfied.
Phalaenopsis vegetative growth temperature is 25 ~ 30 °C. Appropriate increase in temperature can promote vegetative growth (including increased leaf area and leaf number and leaf shape changes). Phalaenopsis is not tolerant of low temperatures. If it encounters low temperatures during cultivation, it will lead to yellowing of the leaves, affecting growth and development, and severe death of the whole plant. Phalaenopsis flowers are very sensitive to low temperatures, and they can cause slight chilling when placed at 12°C for 3 days. Putting them at 10°C for 7 days will shorten vase life. There is a mutual inhibition between vegetative growth and reproductive growth of Phalaenopsis. If it has been cultivated under high temperature, the plants cannot pull stems. It is necessary to induce flower bud differentiation and flowering after a period of low temperature induction. Phalaenopsis enters reproductive growth when the night temperature is lower than 20°C. At this time, the content of starch in the leaves decreases and the sucrose content increases, providing nutrients for the stems. The suitable reproductive growth temperature of most Phalaenopsis is 25/20°C (day/night), and the duration of low temperature treatment is closely related to the formation of pedicels and flower buds. Low temperature treatment time, the proportion of nutritional buds increased, the number of flowers decreased. However, if the temperature is too low, the pedicel development and flower bud differentiation will be slow, and the flowers will be smaller and the malformed flower rate will increase. After the florets are visible, raise the temperature to 30/25°C (day/night) to facilitate flowering.
The pedicel development of Phalaenopsis was the highest in the third and fourth leafhoppers from the parietal lobe. After flowering, it usually takes 1-2 months for vegetative growth to enter the reproductive growth to have good flowering quality. Sometimes in order to improve the flower quality of Phalaenopsis, it is necessary to suppress reproductive growth and prolong vegetative growth. In order to make the phalaenopsis do not pull the stem, it needs to be heated. In the Netherlands, greenhouses are maintained at a constant temperature of 27°C to suppress flowering. Taiwan maintains high temperatures above 27°C in the winter to suppress stemming. Light: Under sufficient light conditions, the photosynthetic efficiency of phalaenopsis plants is high, the number of leaves and leaf area will increase rapidly, and the vegetative period can be shortened. Physiological conditions during the reproductive period will affect the sapling rate, number of flowers, and flowering quality of Phalaenopsis. Under appropriate temperature, the light intensity before the stemming has a great influence on the stemming rate, and low light intensity or darkness can delay the stemming and flowering time, which is one of the technical means of inhibiting the flowering of the orchid. Illumination at the time of stemming is the key to inflorescence quality. If the pedicel develops low light during its development, not only the number of flowers will decrease but also the rate of flower failure will increase. Under normal circumstances, the light should be given for about 3 weeks before the low-temperature pre-sterilization, and the amount of light should be higher than when cultivated. The glare should be maintained during the stemming stage and the foliage can be slightly reddish. After 5 cm of pedicel was removed, the illuminance returned to the level of vegetative growth. Illumination time also affects the flowering of Phalaenopsis. Most phalaenopsis orchids had the highest sapling rate at the 12-hour day, the flowering quality was good and the flowering time was early, but the flowering quality was significantly reduced when the day length was insufficient. Moisture: Moisture can be divided into air relative humidity and root moisture supply. For the regulation of butterfly orchids, the effect of moisture is not as pronounced as temperature and light. Phalaenopsis is native to tropical and subtropical mountainous areas with relatively high relative humidity. It is a high-humidity environment with a well-ventilated and humid environment (relative humidity of 60% to 80%) which is most suitable for its growth and development. Phalaenopsis roots are afraid of soaking in water, and there are no coarse pseudobulbs to store water, and soft rot occurs when humidity is too high. However, if the humidity is insufficient, wrinkles and weakness will appear on the leaves, which will also affect the flowering period and cause the calyx to wither and wither. Nutrients: The nutrients provided by Phalaenopsis during its reproductive growth are closely related to its stemming rate and flowering quality. Phosphorus and potassium are beneficial to the occurrence and development of Phalaenopsis orchids, and the excessively high proportion of nitrogen fertilizer will have an inhibitory effect. In general, phosphorus content in Phalaenopsis leaves is 0.52% to 1.13%. Phalaenopsis if the lack of phosphorus will cause the old leaves to become reddish purple, the tip of the leaves shrink, the growth is blocked, the leaf area and the weight of the matter are reduced. Appropriate application of phosphate fertilizer will promote the extraction of phalaenopsis and increase the number of scapes. The content of potassium in the leaves of Phalaenopsis is about 0.58% to 4.86%, which will increase steadily before the stalks are cut off, and the flowering period will be slightly reduced. The lack of potassium has no significant effect on the occurrence of Phalaenopsis orchids, but potassium can promote the development of pedicels and prolong the flowering period.
In the aspect of phalaenopsis flowering, it is necessary to increase the application amount of phosphate fertilizer and reduce the amount of nitrogen fertilizer before entering the low temperature stemming. Phosphate fertilizers are still dominant during the stem-injection stage. After 5 cm of pedicel extraction, the N, P, and K ratios of fertilization should return to the level of vegetative growth. In order to achieve the purpose of suppressing stemming, the amount of fertilizer applied can be reduced so that the plants do not mature, or the proportion of nitrogen fertilizer is maintained high. Plant Growth Substances: Endogenous hormones undergo a series of changes during the reproductive growth of Phalaenopsis. When the phalaenopsis was treated with low-temperature pretreatment, the content of endogenous auxin (IAA) in the leaves peaked at 2-5 days, and the content of free cytokinin was greater than that of high temperature treatment. During the development of Phalaenopsis orchid, the content of free abscisic acid (ABA) in leaves increased, but the content of buds decreased with the extension of pedicels. The 2 to 3 cm flower-free pedicels contained activated gibberellin (GA1) and there was no presence of non-activated gibberellin (GA8). With the development of pedicel and the degree of differentiation of calyx, the total content of endogenous gibberellin increased. The content of GA1 at low temperatures is higher than at high temperatures.
Application of plant growth substances has a certain regulatory effect on the reproductive growth of Phalaenopsis. In the low-temperature treatment, the appropriate use of 6-benzylaminopurine (BA), can increase the Phalaenopsis stalked rate, pedicel, flowers, and flowering quality, but the use of overdose can also cause sessile malformation, flower failure and other results. When peduncles were extracted, they were treated with GA3 and the number of flowers increased significantly. However, the poor texture of the petals often resulted in abnormal flowers and shortened flowering time. Flower malformation caused by GA3 treatment can be restored by BA treatment. Therefore, GA3 should not be used alone. It is necessary to cooperate with BA to promote the normal differentiation and development of flower buds. Jasmonic acid (JA) application before and after storage of Phalaenopsis can reduce the number of flowers withering. The application of BA and salicylic acid (SA) can increase flower diameter. Exogenous ABA significantly inhibited the stem and flowering of Phalaenopsis, and the inhibition increased with increasing concentrations. Spray dwarfing agent has the effect of increasing flower diameter and extending flowering period. In addition, ethylene has an important influence on the flowering of Phalaenopsis. Bacteria: Any fungal that can establish a symbiotic relationship with Orchidaceae plants is called blue symbiotic bacteria, or simply called blue fungus. Orchid seeds are very subtle, mature without endosperm, in the natural world need to be symbiotic with blue bacteria to sprout growth. The maturity of orchids is less dependent on orchids. However, inoculation with the appropriate bacterium can increase the siphoning rate, flowering number and flower diameter of phalaenopsis. Effects of Ethylene on the Aging of Phalaenopsis Flowers and the Effects of Inhibiting Ethylene on Flower Aging: Flower aging is caused by a series of physiological and biochemical changes. The most obvious manifestation is the withering of petals. The aging of flowers is related to ethylene. When the flower matures, the ethylene synthesis gene begins to express, and the production of ethylene increases with the age of the flower. Phalaenopsis flower aging is affected by both endogenous ethylene and external ethylene. Phalaenopsis flowers are very sensitive to ethylene, as long as the external application of 90nL / L of ethylene will promote flower withering. Phalaenopsis increases the sensitivity to ethylene after pollination, and it also leads to an increase in ethylene production, which can cause rapid flower aging.
Phalaenopsis is the most important potted orchid. In the process of sale and storage, the flowers will suffer from adversity, resulting in a decline in quality. The most serious problem is the elimination of ethylene. During the dark storage and transportation process, the self-generated ethylene of potted flowers will increase the ethylene concentration in the plants and the environment, resulting in yellowing of leaves, delayed opening of flowers, and even flowering and falling down. Effects of 1-MCP on Flowering Quality: Ethylene's regulation of physiological processes in plants can be divided into two aspects: ethylene biosynthesis and signal transduction. Therefore, inhibition of ethylene damage can also reduce biosynthesis and block signal transmission. Both are conducted. Both the ethylene synthesis inhibitor, aminooxyacetic acid (AOA) and the ethylene inhibitor, 1-methylcyclopropene (1-MCP), can reduce ethylene hazards, with 1-MCP being the most used and most effective.
1-MCP is a cycloolefin compound that competes with ethylene for binding sites on receptors, preventing ethylene from interacting with the receptors, thereby delaying ethylene-induced aging. 1-MCP not only strongly blocks the physiological effects of endogenous ethylene, but also inhibits the induction of endogenous ethylene by exogenous ethylene. It is currently the best ethylene receptor inhibitor. As long as there is a low concentration of 1-MCP protection, ethylene can slow the rapid wilting caused by Phalaenopsis flowers. Different 1-MCP treatment concentrations and time have different protective effects on Phalaenopsis flowers. To achieve absolute protection, tests are needed to determine the concentration and time required. 1-MCP can also inhibit floral aging caused by the increase of ethylene caused by pollination in Phalaenopsis.
1-MCP binds to ethylene receptors for about 7 to 12 days. During this time, ethylene can be blocked. After the protection period, the receptors can bind to ethylene or new tissue receptors are formed. Formation leads to a decrease in ethylene inhibition by 1-MCP treatment. Therefore, 1-MCP has a certain period of validity for the protection of Phalaenopsis flowers. Treated with 800nL/L1-MCP for 8h, the absolute protection period of the flowers of P.amabilis was about 6-8 days. Phalaenopsis bud elimination problems and the overcoming of Phalaenopsis growth and development often occur in the development of flower buds, water loss and death can not be flowering phenomenon, known as Lei. Most of the buds are caused by environmental changes affecting the balance of endogenous hormones in plants and maladaptation of carbohydrates, resulting in flower bud nutrients and insufficient water. The improper treatment of the environmental factors, nutrients, and plant growth substances that affect the flowering of Phalaenopsis can lead to the occurrence of Phalaenopsis buds. For example, when the phalaenopsis is cold-flowered, if the light is too weak, it will not only lead to a decrease in the number of flowers, a delay in the flowering period, but also an increase in the number of flower pods. Inappropriate time from low temperature to high temperature after phaeoid stemming will also lead to elimination. bud. In view of the causes of the buds of phalaenopsis, corresponding measures can be taken to control them, such as increasing the illuminance, inhibiting the effect of ethylene, and applying plant growth substances such as GA3 or BA.
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