Studies on Pollen-Pistil Interaction in Intergeneric And Interspecific Crosses of Oilseed Brassicas And Related Genera
Pollen-pistil interaction was studied in interspecific, interploidal and intergeneric crosses of oilseed Brassicas and related genera. A significant reduction in pollen germination on the stigma was observed in the crosses, Brassica juncea × Brassica carinata, Brassica juncea × Eruca sativa and Brassica nigra × Brassica juncea, as compared to the respective self-pollination events. In the case of hybridization event, Brassica juncea × Brassica tournefortii, only 57% pollens could germinate and pollen tubes entered slowly in the stylar region and reached up to the ovary within 12 HAP (hours after pollination). However, in the cross Brassica juncea × Brassica carinata, it took 3 HAP for the pollen tubes to reach the ovary. Abnormal growth in pollen tubes was observed in interspecific and intergeneric crosses. In Brassica napus × Brassica carinata cross, crossability barriers at the level of pollen-pistil interaction were of low intensity as evident by high pollen germination at par to self-pollination. No evidence for inhibition in pollen germination was observed in the crosses Brassica juncea × Lepidium sativum and Brassica juncea × Brassica tournefortii. A significant difference was observed in the elongation of pollen tubes in different crosses. Numerous callose plugs were also observed in the interspecific and intergeneric crosses.