Orchids and Plant growth regulators

Carry forward the national orchid culture and spread the knowledge of orchids

What is a plant growth regulator, Lanyou may not quite understand, but when it comes to hormones, Lanyou will be clear. in the past, like everyone else, I have little knowledge of hormones. I often hear Lanyou say that this is a hormone seedling, that is a bud driven by hormones, and so on, but when asked what hormones are used, the interests of hormones to orchids are also at a loss, thus producing a sense of mystery to hormones. Recently, I often consult botanists, so I have some understanding of hormones, so let's talk about the knowledge of plant growth regulators (hormones) objectively, so that Lanyou can have a certain understanding of hormone orchids.

Strictly speaking, plant growth regulators do not belong to fertilizers, should belong to a kind of pesticides, but have something to do with fertilizers. The process of plant growth and development is subject to external environmental conditions. Such as water, sunlight, plant materials, temperature and other effects and the control of internal genetic factors, while the regulation and control of plant growth activities are some metabolites, that is, plant hormones. Plant hormones are endogenous active substances produced by plants, which can be transferred from synthetic organs and such tissues to other organs or tissues. At present, there are five main types of plant hormones: auxin, gibberellin, cytokinin, abscisic acid and ethylene. In addition, scientists have also found some other plant hormones such as brassinolide, salicylic acid, jasmonic acid and so on.

There are five types of functions of plant hormones:

I. the physiological function of auxin

Promote growth, but inhibit growth at high concentration

Promote the formation of adventitious roots of cuttings, for example, the main component of hairy root element is gallic acid.

It can regulate the transport of nutrients and induce seedless fruits.

Other physiological functions such as inducing apical dominance, promoting pineapple flowering, inducing female flower differentiation and so on.

Second, the physiological function of gibberellin

1. Promote the elongation and growth of stem.

2. Induce flowering

3. Break dormancy

4. Promote male flower differentiation, GA treatment makes monoecious plants have more male flowers.

5. Inducing parthenocarpy and so on.

III. Physiological functions of cytokinins

1. Promote cell division, mainly play a role in cytoplasmic division.

2. Promote bud differentiation.

3. Promote cell expansion

4. promote the development of lateral buds and eliminate apical dominance.

5. Delaying the aging of organs, which can be used to deal with fruits and flowers to keep them fresh and green, and to prevent fruit falling.

6. Breaking the dormancy of seeds can break the dormancy of seeds that need light instead of light.

IV. Physiological effects of abscisic acid

1. Promote dormancy

2. Promote stomatal closure

3. Inhibit growth, and the inhibitory effect is reversible.

4. Promote shedding

5. To increase stress resistance, ABA is called stress hormone.

V. physiological function of ethylene

The main results are as follows: 1. Change the growth habit and cause the plant to show unique triple reaction and upward growth.

2. Promote maturity, known as ripening hormone

3. Promote shedding, which is the main hormone to control leaf shedding.

4. promote flowering and female flower differentiation.

5. induce the formation of adventitious roots of cuttings, break the dormancy of seeds and buds, and induce the secretion of secondary substances.

Since the discovery of plant hormones, people have wanted to use them in agricultural production. However, the content of natural hormones in plants is very small, so scientists use other methods such as microbial fermentation to concentrate and extract, or chemical methods to mimic the chemical structure of plant hormones. This kind of artificially synthesized and artificially extracted physiologically active substances are called plant growth regulators.

Now let me briefly introduce the types of plant growth regulators on the market:

I. auxin auxins:

1. Indoleacetic acid is mainly used to promote rooting. Promote cell growth and cell differentiation.

2. 2Jing 4D, which has the effect of auxin, promoting at low concentration and inhibiting at high concentration.

3. Naphthylacetic acid mainly promotes cell growth and rooting.

4. Love to harvest, which is the sodium salt of nitrophenol compounds, which is beneficial to plant growth and development. Rooting, flowering and fruiting can obviously promote. If used too high, it can inhibit the growth of plant buds.

II. Gibberellins

Gibberellin, also known as 920, mainly promotes cell growth, breaks dormancy and promotes early flowering.

3. Cytokinins:

1. 6-benzylaminopurine, or 6-BA, has high cytokinin activity. It is often used in tissue culture. It has the advantage of breaking the top and promoting the growth of lateral buds.

2. Kinetin, 6-furan methyladenine, promotes cell division and tissue differentiation and delays the degradation of protein and chlorophyll.

4. Plant growth retardation and inhibition:

1. B9, also known as Bijiu, mainly inhibits the transport of auxin and gibberellin biosynthesis in plants, slows the vegetative growth of plants, and makes the leaves green, small and thick.

2. Triadimefon, a low-toxic fungicide, can thicken the leaves, reduce the leaf area and delay the growth of the basin.

3. Abscisic acid promotes plant senescence and inhibits the physiological processes regulated by plant hormones (auxin, gibberellin and cytokinin).

Of course, there are many more, so I won't point them out here!

With regard to the application of plant growth regulators, it is more or less useful in Lanyou, everything has its advantages and disadvantages, sprouting more and growing rapidly after use. However, the resistance of orchids decreased rapidly, and the seedlings were easy to fall or the new seedlings were weak. Now the orchids on the market are dedicated to sprouting and rooting, more or less contain certain plant growth regulators, but most of Lanyou do not know it. Orchids cultivated naturally have good resistance to stress, and the ability to resist diseases and insect pests is better than that of plant growth regulators. In addition, the concentration of plant growth agents is not easy to grasp, because the dosage of plant growth regulators is very small, and some are 1/1000000, which are generally not easy to grasp, and if the concentration is high, it is easy to have the opposite effect, such as high gibberellin concentration, it is easy to make orchid new buds grow crazy, and the consequence is lodging. When the leaves become thinner, it is easy to fall seedlings. In the case of high concentration of 4D, it is necessary to inhibit growth, or even kill plants, and so on. Therefore, orchids should be cultivated with little or no plant growth regulators.

(the hormone used for the dwarfing of orchids has been used for a long time (B9), which can be combined with the potted soil when it needs watering. Spraying 0.2% Bijiu solution every 7 to 10 days until the leaves are wet on both sides can effectively control the plant height, grow sturdy, and the flowers are large and colorful.)

Attached: list of uses of plant growth regulators

Plant growth regulators have a variety of uses, it can be said that from seed germination, rooting, long leaves to flowering and fruiting, and then the formation of seeds, as well as postharvest fruits and vegetables preservation, seed storage can be regulated by growth regulators. The various uses and the names of applicable growth regulators are listed below.

Name of plant growth regulator suitable for use

Prolong dormancy of storage organs, such as anthocyanin, sodium naphthalene acetate, methyl naphthalene acetate.

Breaking dormancy promotes the germination of gibberellin, kinetin, thiourea, chloroethanol and hydrogen peroxide.

Promote the growth of stems and leaves gibberellin, 6-benzylaminopurine, brassinolide, triacontanol.

Promote rooting of indolebutyric acid, naphthalene acetic acid, 2mai 4murD, Bijiu, paclobutrazol, ethephon, 6-benzylaminopurine.

Inhibit the growth of stem and leaf buds by paclobutrazol, Youconazole, dwarf, Bijiu, Pixar, triiodobenzoic acid, chlorophyllin, powder.

Promote flower bud formation of ethephon, Bijiu, 6-benzylaminopurine, naphthoacetic acid, 2meme4murD, dwarf.

Inhibit the formation of gibberellin from flower buds and regulate phosphine.

Naphthalene acetic acid, carbaryl, ethephon, gibberellin, indole ester, 6-benzylaminopurine.

Bao Hua Bao Guo 2pm 4murD, Naphthylacetic acid, Fangluosu, Gibberellin, Dwarf, Bijiu, 6-benzylaminopurine.

Prolong the florescence of paclobutrazol, dwarf, ethephon, than for a long time.

Induction of female flower ethephon, naphthalene acetic acid, indole acetic acid, dwarfin.

Induction of gibberellin in male flower

Cut flowers fresh-keeping aminoxyethyl vinyl glycine, aminooxyacetic acid, silver nitrate, silver thiosulfate.

Form seedless fruit gibberellin, 2mai 4rel D, Fangluo, naphthalene acetic acid, 6-benzylaminopurine.

Promote fruit ripening ethephon, longer than.

Delaying fruit ripening 2ju 4murD, gibberellin, Bijiu, kinetin, naphthalene acetic acid, 6-benzylaminopurine.

Anti-aging 6-benzylaminopurine, gibberellin, 2meme4murD, kinetin.

Increase the content of amino acids paclobutrazol, paracetamol, indole ester.

Increase protein content of paracetamol, simazine, atrazine, naphthylacetic acid.

Increase sugar content, increase glyphosate, regulate phosphine, Pixar.

Promote fruit coloring for a long time, indole ester, paclobutrazol.

Increase the fat content of naphthalene acetic acid, penicillin, orthopedics.

Improve resistance to abscisic acid, paclobutrazol, Bijiu, dwarf.

The issue of hormones is a sensitive topic, generally Lanyou talk about the color change, welcome to exchange, the aim is to let Lanyou recognize and identify hormone vaccines.

The effect of growth hormone on promoting Bud and Bud of Orchid

In the various growth and development processes of orchid germination, growth and flowering, good results can be obtained by using plant growth hormone to treat different parts of orchid plants. In particular, it plays a special role in the preservation, continuation and development of some rare or endangered species, and also plays an extraordinary role in speeding up breeding, enhancing species exchanges with the outside world, and improving economic benefits.

Break dormancy and stimulate the germination of latent buds of pseudobulb (Reed head). The old false bulbs that remained year by year were separated from the plant, and the connected 2-3 bulbs were taken into a group, then the remaining old leaves were cleaned and washed to dry, but the latent bud eyes should not be injured in the whole process. The step of hormone treatment is to drip the latent bud eye with 0.05% (500PPm) gibberellin (GA3), and then treat the residual root cap and the base of the pseudobulb with 0.1% (1000PPm) indolebutyric acid (IBA). After treatment, it was implanted into the pot according to the conventional cultivation methods according to different varieties. The trial showed that the number of sprouting plants of orchid plant was significantly higher than that of the control.

Promote multiple plants and grow fast. At present, the main way to improve the reproduction coefficient of rare and excellent varieties is through ramet. Only a few new plants of Dacong orchid can produce new seedlings in the previous year, but there are no or few new seedlings in the old plants for many years, and the propagation of individual plants will affect the growth potential, and the new plants become smaller, even lead to the death of the mother plant. Through the treatment and regulation of plant growth substances, new plants can be induced and growth can be promoted. The practice is to remove the orchid bushes from the basin, rinse the soil between the remaining roots and plants, and dry them until the fleshy roots become soft or brittle; separate them one by one with a sharp knife, then soak them in 0.08% (800PPm) carbendazim solution for a while; still slightly dry, dip cotton into 0.01% (100ppm) 6-benzyladenine and coat the pseudobulbs; then soak from the root cap to the root with 0.1% (1000ppm) indolebutyric acid. The application practice shows that the combination of the three treatments can reduce the death of pseudobulbs, increase the number of plants and improve the growth potential.

Promote budding and flowering. The flower bud differentiation of orchids is not only restricted by cultivation management (including light hours, carbon-nitrogen nutrition ratio of plant life cycle, ramet degree, fertilizer and water status, etc.), but also plays an important role in the regulation of variety characteristics and exogenous hormones.

Taking Cymbidium as an example, under normal conditions, the growth of orchid plants has gradually matured by the end of July and the beginning of August. Spraying 0.03% (300ppm) paclobutrazol (PP333) on orchid leaves at this time could promote pseudobulb expansion and provide material basis for flower bud differentiation in August and September. Cover the basin when spraying leaves with paclobutrazol, let alone irrigate the soil directly. From the actual use, the orchid leaves sprayed with paclobutrazol only thickened and darkened, and it had no effect on controlling the leaf length; but if the liquid was sprayed to the soil, the flower stem was obviously shorter than the normal, thus losing the appreciation value of the orchid.

When using plant growth hormone, we must pay attention to the following two points:

The use of plant growth hormone should be carried out in the growing season and the physiological development stage of the action site, so as to facilitate the transport and metabolism of substances. The temperature during treatment is not lower than 15 ℃.

Plant growth hormone can only regulate the growth and development of plants, and can not replace management and fertilizer. Only by applying plant growth substances in fine management conditions and reasonable fertilization measures can we get twice the result with half the effort.

It is suggested that for those bad, ready to throw away the good flower false bulbs, rootless grass, etc., you can try, maybe there can be a big surprise, as for the strong grass, don't ask for trouble.

Orchids, you are a good teacher on the way to raise orchids.