How many kinds of cytokinin plant growth regulators are applied into the vegetable planting in China?
Cytokinin plant growth regulator is a class of plant hormones to promote the cell division. Among such substance, furfurylaminopurine (kinetin) is the first to be found. Later, natural and synthetic compounds of the same physiological activity with the furfurylaminopurine are known as cytokinins. More than 10 kinds of cytokinins can not only promote the cell division and expansion, but also induce bud differentiation and delay leaf senescence, etc., such as 6-benzylaminopurine, furfurylaminopurine, KT-30, 5406 cytokinins, Tongwei 1st, isopentenyl adenine, zeatin, etc. Among them, the 6-benzyladenine with stronger activity is the most commonly used in the vegetable planting in China.
a. 6-BA is a cytokinin, also known as 6-benzyl adenine, 6-benzyl aminopurine, 6-(benzylamino) purine, BA, BAP, etc. It is a synthetic purine derivative, which can dissolve in alkaline or acidic solution. Besides, it can not only delay plant senescence and prolong shelf life and freshness, but also improve the germination rate and promote female flower growth and bear fruit for some vegetables. Cytokinin products are generally 95% of powder.
b. Furfurylaminopurine (cytokinin) is also known as kinetin and so on, with kinetin as the common name in English and KT for short, 6-furylmethyl adenine and 6-furfuryl adenine for chemical name. KT-30 is a new plant growth regulator with its activity similar to the BA. It can not only promote the cell division and break the dormancy, but also prevent plant cell senescence and fruit abscission and lift the apical dominance, etc. Besides, this hormone can promote to bear fruit during the period of the pollination for early-maturing watermelons. This product is white or light yellow crystalline powder with stable properties; it is insoluble in water, but slightly soluble in ethanol, butanol, acetone, ether and other organic solvents. In the course of preparation, it first dissolves in a small amount of alcohol or acid, diluted with water to the desired concentration until completely dissolved.
c. 5406 cytokinin is microbial agent from 5406 bacterial manure (actinomycetes). There are two categories: one is bacterial powder containing live spores, which are white granular powder with a borneol fragrance; the other is the 5406 cytokinin, which is white powder containing no live spores with cytokinin as the main component. The cytokinin is basically non-toxic for human and livestock. And it can not only stimulate vegetable growth and improve disease resistance and cold resistance, but also prevent premature senescence and protect flowers and fruits, etc. The main formulations are 5406 bacterial powder and 5406 cytokinin.
d. Tongwei 1st is a new cytokinin antibiotic. Its products contain a lot of cytokinins, zeatins, amino acids and antibiotics. Applied to crops, it can not only promote the cell division more quickly and strengthen the photosynthesis for plants, but also accumulate dry matter more and faster and enhance cold resistance and disease resistance of crops as well as improve product quality.
e. Isopentenyl adenine, also known as plant cytokinin, with zeatin plant hormone and isopentenyl adenine as the active ingredient, is made by the microbial fermentation. Wettable powder is beige in appearance; it can not only stimulate the cell division and promote the formation of chlorophyll, but also enhance the resistance, etc.