Effects of Gibberellic Acid and Streptomycin on Pollen Germination and Ovule and Seed Development in Muscat Bailey A

Experiments were conducted on cv. Muscat Bailey A (Vitis vinifera x Vitis labrusca) to study the activity of SM on ovule development, pollen germination and pollen tube growth with regard to seedlessness induction. Clusters were dipped in either GA 100 ppm, SM 200 ppm or in a combination of GA + SM at different dates during pre-bloom stage. Pollen germination and pollen tube growth were severely inhibited by GA while inhibition on ovule development was less expressive. SM added to GA solutions improve seedlessness of Muscat Bailey A when applied one to two weeks before anthesis. Pollen germination and pollen tube growth were not affected when clusters were treated with SM alone. Ovule size and internal structure did not differ between SM treated clusters and the control clusters till the blooming date. Periodical sampling and analysis of ovules showed that the effect of SM on ovule development became apparent after anthesis. SM inhibited endosperm formation, resulting in production of empty seeds of variable sizes.