Chemical Hybridizing Agents (CHA) – A tool for hybrid seed production – A review
The failure of a plant to produce functional gametes is known as sterility. Sterility induced by application of certain chemicals like, auxins and antiauxins (NM, TIBA, 2, 4–0, MH, etc.), halogenated aliphatic acid (FW-450, dalapon, etc.), gibberellic acid (GA3), etheophon, DPX-3718, arsenicals (MSMA, DAA, ZMA, etc.), RH-531, RH-532 etc. These chemicals are called gametocides since they lead to pollen abortion and there by cause male sterility, some times it results in female sterility also. So the term chemical hybridizing agents (CHA) are used since after the entire primary objective is to produce a hybrid. A number of CHAs have been reported to cause male sterility for production of hybrids. Therefore, no need to developed maintainer or restorer lines and save time, labor and money. In the present review, different aspects of CHA viz., characteristic, mode of action, stage of treatment, application doses, etc. for different CHAs and also for different crop wise.