Induction of cytomixis affects microsporogenesis in Sesamum indicum L. (Pedaliaceae)

Cytomixis was recorded during microsporogenesis in sesame (Sesamum indicum L.), a member of the family Pedaliaceae. The phenomenon of cytomixis was observed at various stages of meiosis in 0.5% sodium azide (SA) treated populations of Sesamum indicum L. Cytomixis was observed to occur through various methods, i.e. by forming cytoplasmic channels and direct fusion of pollen mother cells (PMCs), the former was more frequent than the latter. The migration of nuclear content involved all the chromatin/chromosomes or part of it from donor to recipient cell/cells. Some completely empty meiocytes were also observed. Stickiness, precocious movement, laggards, unorientation and micronuclei were observed in almost all the sets treated with various doses of SA. Increase in the doses of SA had a positive effect on the percentage of PMCs showing cytomixis and chromosomal abnormalities. The impact of cytomixis on meiotic behaviour, reduced pollen viability and heterogeneous sized pollen grains were observed.