Efficient production technology of test-tube plantlets of Phalaenopsis

Phalaenopsis is a kind of orchid with high ornamental value, which is known as "queen of orchid". Its plant type is very peculiar, it is a single-stem aerial orchid, and its roots like to expose above the plant material or protrude the basin bottom to absorb water and nutrients from the air. The pedicel is drawn from the axil of the leaf, curved and curved. There are nodes on the stem, and the flowers bloom on the upper node, one after another. There are many colors, such as scarlet, pure white, lilac, goose yellow and azure blue, some varieties are two-color or tricolor, and have stripes or spots, colorful. Each stem can bloom 7 to 12 flowers, with a maximum of 70 flowers. However, because its plants rarely develop lateral branches, it is difficult to carry out conventional asexual reproduction, so it is difficult to meet the growing needs of Phalaenopsis enthusiasts. After years of research and practice, a set of technical processes for rapid propagation and efficient production of Phalaenopsis have been established. and in Phalaenopsis excellent large flower variety "Jubaohong Rose"Huolong" and small safflower variety "Mantianhong" test-tube plantlet production has been successful, gradually forming a scale of annual production of hundreds of thousands of seedlings of various specifications and 100,000 flowering plants.

1. The technical process of mother plant selection → primary generation to induce → cluster bud differentiation → subculture proliferation → strong seedlings rooting → exercise seedlings → out of the bottle transplanting.

(2) initiation and induction (1) selection of mother plant. Since tens of thousands of tissue culture seedlings come from the same explant, the selection of mother plants should be particularly careful and follow three basic principles: 1. The whole population showed the typical characters of the variety. two。 The population grew and developed well and there was no common infection of specific diseases, such as East Asian orchid mosaic virus and toothed orchid rosette virus. The phenomenon of co-infection of these two viruses is very common, and the mother strain should be tested for the virus first. 3. A strong single plant with excellent characters was selected as the mother plant in the population that met the above conditions. (2) primary induction. The lower dormant bud of the flowering pedicel was selected as the material, the pedicel that cut off the upper inflorescence was cut into 5 × 7 cm stem segments, rinsed with tap water for 1 hour, then soaked in 75% alcohol on the ultra-clean worktable for 1 minute. After rinsing with sterile water, soak in 0.1% mercury solution for about 10 minutes, then rinse with aseptic water for 3 times, peel the bracts of dormant buds on the sterile inoculation plate. Soak in 0.05% mercuric solution for 4 minutes and rinse with sterile water for another 3 times. The treated pedicel was cut into 3-4 cm stem segments, each with a lateral bud, and the induction medium was inserted downward into the base, and then it was cultured in the culture room with light intensity of 2000 lux, light time of 12 hours per day and culture temperature of 25 ℃. The lateral buds began to sprout after 10 days, and the induction rate could reach 90%. After 30 days, the lateral buds could grow into seedlings. In the process of induction of pedicel dormant buds, a few dormant buds germinated and grew into delicate stem stems similar to pedicel lateral branches. when they grew to 3 cm and had 2 or 3 buds, they were cut off from the pedicel and re-segmented, with one bud in each segment, and the base was re-placed into the induction medium to continue to induce seedlings.

Third, differentiation and proliferation of pedicel lateral buds induced seedlings, the seedlings were cut off from the pedicels and inoculated in the differentiation medium. Then it was cultured in the culture room with light intensity of 2500 ~ 3000 lux, light time of 10 hours per day, and culture temperature of 25 ℃. After subculture every 45-50 days and 2-3 times, the clustered buds could be differentiated. The differentiated tufted buds were carefully isolated, inoculated in the proliferation medium, and then cultured in the culture room with light intensity of 3000 lux, light time of 10 hours per day and culture temperature of 25 ℃. It was subcultured every 50 days, and the multiplication multiple was more than 3 times. With the increase of subculture times, high concentration of 6-BA will increase the multiple of proliferation, but it will also cause seedling variation. After 10 generations of proliferation or after the mutants began to appear, only a lower concentration of 6-BA can be used to promote the growth of clustered buds and eliminate the mutants in time. The proliferation and growth of clustered buds had a certain population effect. When clustered buds were cut into only 1-2 buds, the proliferation of clustered buds decreased greatly, and most of them did not proliferate after a subculture cycle, but the seedlings grew a little. When the tufted buds were cut into 3-5 buds, the proliferation of clustered buds was more normal. When cutting clump buds, the cluster buds can only be separated gently, and can not be cut around the cluster buds, otherwise the medium will be browned quickly due to too many cutting wounds, which is not conducive to the growth and differentiation of cluster buds, and even cause the death of cluster buds. Cross-cutting of some larger tufted buds (bud height more than 1.5 cm, uniaxial stem diameter more than 0.5 cm) can greatly increase the multiplication ratio. After cross-cutting, a new round of cluster buds will grow on the base of cluster buds, and the multiplication multiple can be increased by 5 times. Because the uniaxial stem of Phalaenopsis is short, it is necessary to accurately grasp the cutting position when cutting, otherwise the bud will be cut to death or the multiplication multiple will not be achieved because the terminal bud has not been cut off.

4. Rooting and refining seedlings when the buds grow to 1.5cm high and have 2 leaves, they are transferred to the rooting medium and cultured in the culture room with light intensity of 3000 lux, light time of 12 hours per day, and culture temperature of 25 ℃ ~ 28 ℃. Rooting begins after 20 days. After rooting, the quality and survival rate of seedlings in culture flask could be significantly improved when the seedlings were cultured under the condition of light intensity 8000 ~ 10000 lux and light time 12 hours a day for about 20 days. When the seedling is as high as 4 cm and the number of leaves is 3-5, it can be planted in a bottle.