Callase enzyme activity in thermo sensitive genetic male sterility (TGMS) lines of diploid cotton (Gossypium. arboreum L).

Seven TGMS lines under investigation, showed similar results in their fertile anthers at premeiosis stage showing less activity of enzyme callase. At microspore stage the enzyme activity was high, while at all other times there was no callase activity. TGMS sterile anthers displayed higher activity at premeiosis stage, high activity at tetrad stage but poor activity at microspore stage. During tetrad stage, TGMS sterile anthers had high callase activity, for early release of poorly developed microspores, as compared to that in fertile anthers. At tetrad releasing microspores stage, during which fertile anthers had strong callase enzyme activity, led to microspores being released normally and were developed normal pollen grains as compared to sterile anthers.