Histological studies on cytoplasmic and ga-induced male sterile lines of sunflower

Microsporogenesis and pollen development in one cytoplasmic male sterile line, namely, CMS-2 and in GA-induced male sterile plants of the variety EC-68415 was studied in comparison with the male fertile plants.

In the cytoplasmic male sterile line there was degeneration of primary sporogenous cell. Disorganisation of tapetal cell was also observed. As a result, there was no meiosis taking place and anther locules remained hollow.

In the case of GA-induced male sterile plants the mechanism was almost similar to that of cytoplasmic male sterile lines. The effect of GA was noticed at premeiotic stage whereby the formation of sporogenous tissue was adversely affected.