Cytokinin (CTK) is a large category of plant growth regulators. Naturally synthesized ones include kinetin (KT), zeatin (ZT), and dihydrozeatin (DHZ), all of which are purines. Based on the study of the structure and function of natural cytokinins, artificially synthesized ones include purine-type 6-benzylaminopurine (6-BA); phenylurea-type chlorfenuron (CPPU) and thidiazuron (defoliant).
Functions of cytokinins
1. Promote cell division and cell or callus growth;
2. Promote seed germination and root, stem and leaf growth;
3. Break apical growth to promote lateral bud growth and induce female traits;
4. Promote flower bud differentiation, promote flowering, prevent flower drop, increase fruit setting rate and fruit growth;
5. Inhibit chlorophyll decomposition, promote enzyme activity, keep green and delay plant aging, that is, prevent leaf aging, extend vegetable storage time, prevent fruit tree fruit drop, increase single fruit weight and quality, etc.;
6. Increase stress resistance, with disease resistance, insect resistance, drought resistance, high temperature resistance, salt and alkali resistance, etc.
Toxicity
Kinetin and zeatin are non-toxic, 6-benzylaminopurine, thidiazuron, chlorfenapyr are all low-toxic pesticides.
Kinetin (KT)
Kinetin (KT), also known as 6-furfurylaminopurine, is isolated from herring sperm cells and is the first discovered natural cytokinin.
Functions:
1. Promote cell division, accelerate protein synthesis and cell growth;
2. Preservative effect, delay the degradation of chloroplasts and proteins, thereby extending the storage time of fruits, vegetables and other crops;
3. Promote tissue differentiation, that is, strengthen the growth and proliferation of buds and the formation of roots;
4. Improve seed germination rate. Appropriate concentration can make seeds germinate in advance, and high concentration will inhibit seeds;
5. Enhance stress resistance, by increasing the activity of antioxidant enzymes, so that it has functions such as drought resistance, cold resistance, salt damage resistance, waterlogging resistance, and cadmium stress resistance;
6. It can improve the healing or survival rate of plants during cutting and grafting propagation.
Zeitin (ZT)
Zeitin (ZT), also known as hydroxyene adenine, is a natural purine cytokinin obtained by splitting from immature corn seeds.
Functions:
1. Stimulate plant cell division;
2. Promote chlorophyll formation, keep green and delay the aging of plant organs such as leaves;
3. Accelerate plant metabolism and protein synthesis, continuously accumulate sugar or organic matter in the plant, promote early maturity and increase yield of crops;
4. Improve plant disease resistance.
It is safe for plants, the environment and humans, and is insoluble in water and moves slowly in the plant body.
6-Benzylaminopurine (6-BA)
6-Benzylaminopurine (6-BA) is an artificially synthesized purine cytokinin, which is more active than kinetin but weaker than zeatin.
Functions:
1. Break the apical dominance, thereby promoting the growth of lateral buds and accelerating branching;
2. Preserve flowers and fruits, increase the number of female flowers, and thus increase the fruit setting rate and yield;
3. Preserve freshness, slow down the decomposition rate of chlorophyll, delay the aging of leaves and increase the storage time of fruits, vegetables and other crops;
4. Promote seed germination, break seed dormancy and accelerate seed germination;
5. Promote flower bud differentiation and flowering, which can promote the growth of lateral buds and increase the flowering rate;
6. Promote the enlargement and fattening of crop cells, which can increase the number and weight of single fruits;
7. It can increase the survival rate of grafted seedlings or plants;
There are more than 20 types of single-dose dosage forms, including suspension, soluble powder, soluble solution, etc.
Thidiazuron (TDZ)
Thidiazuron (TDZ) is a phenylurea cytokinin.
Function:
1. Used as a defoliant, it accelerates the natural formation of separation tissue between petioles and stems to achieve the effect of defoliation;
2. Promotes cell division and induces callus tissue, which can promote fruit expansion and early maturity. Its activity is much stronger than other cytokinins;
3. Promotes photosynthesis, improves crop yield and quality, and delays plant aging;
4. Has stress resistance.
Single-dose formulations include more than 60 types such as soluble concentrates, wettable powders, water-dispersible granules, suspensions, and dispersible oil suspensions.
Forchlorfenuron(CPPU)
Forchlorfenuron (CPPU) is a phenylurea cytokinin.
Function:
1. Promote cell division and expand cell volume;
2. Promote organ formation and protein synthesis
3. Break the dominance of apical buds and promote the growth of lateral buds;
4. Promote seed germination and break seed dormancy;
5. Promote fruit setting rate, increase single fruit weight and quality, and make the fruit swell;
6. Has stress resistance;
7. Anti-aging effect.
There are more than 10 single-dose dosage forms, including soluble solution, soluble powder, wettable powder, etc.
