Pleiotropic Effects of .GAMMA.-Irradiation on In vitro Pollen Germination and Fertility in Soybean

Abstract

Pollen germination and tube growth are the necessary events for fertilization and seed formation. The objective of the present investigation was to study and compare in vitro germination characteristics of pollens from γ-ray irradiated seeds. Considerable differences in pollen viability and tube length alongwith increasing doses of gamma-ray have been observed in the study. Similarly, pollen germination percentage also decreased significantly with the increased doses of γ-ray. The study revealed that at the 400 Gy and 500 Gy doses most of the pollen grains, though viable did not germinate. The pollen morphology and pollen tubes were also found affected at higher doses viz. 300, 400 and 500 Gy, while, an enhancement of tube length has been observed at 100 Gy dose but it was statistically insignificant. It appears that at 400 Gy dose pollen grains start losing their property of tube formation. Normal seed percentage and pod formation also registered a decrease alongwith increase in dose of gamma ray. This feature can be exploited in breeding programmes for raising male-sterile lines in soybean since it is a highly self-pollinated crop and male-sterile lines can prove to be of much use in this case.