Abstract:

Content of 4 Phytohormones, IAA, GA₃, ZR and ABA, were measured by enzyme-linked immunosorbent assay (ELISA) in anthers of cytoplasmic male sterile cotton and its maintainer, restorer and hybrid F₁ during five development stages to study the relationship between male sterility and phytohormone changes. The results showed that the differences of IAA, GA₃, ZR and ABA contents were not significant among the fertile anthers from maintainer, restorer and hybrid F₁, but very significant between fertile and sterile anthers. Fertile anthers were higher in IAA, GA₃ and ZR contents, but lower in ABA content than sterile anthers, especially at the abortion stage of pollen mother cells. According to abortion characteristics and hormone changes of sterile anther, it was suggested that IAA, GA₃ and ZR deficiency might be associated respectively with the inhibition of starch grain accumulation, expansion-restraint of pollen mother cells and tapetal cells and no tetrad formed, and that abortion and even death of pollen mother cells and tapetal cells in sterile anther might be accelerated by high ABA accumulation.

Key words: Cotton, Cytoplamic male sterility, Phytohormones