Volume 6, Issue 6, December Issue - 2018, Pages:947-958
Authors: Dibosh Bordoloi, Debojit Sarma
Abstract: Ten selected rice genotypes adapted to rainfed lowland ecosystem of Assam was evaluated for their ability to germinate and grow underwater (anoxic condition) in comparison to the aerobic condition. Anaerobic germination was allowed 10 cm water depth in pots partially filled with soils inside the net house, while Petri dishes lined with filter papers were used for aerobic germination. A general trend in reduction of germination and seedling traits were observed for all the genotypes. Three of the tolerant genotypes namely Badal, Swarna Sub 1 and Solpuna showed germination enhancement under anaerobic condition, the highest significant increase (24.3%) being registered for Badal, a cultivar adapted to semi-deep water (42-75 cm) situation indigenous to Assam followed by Swarna Sub 1 (11.6%) and Solpuna (2.1%). Both Badal and Swarna Sub 1 are tolerant to submergence at vegetative stage. Solpuna, another local cultivar adapted to the lowland ecosystem with no known submergence tolerance recorded the highest shoot length under the anoxic condition which was significantly superior to its aerobic performance. The reduction in root length was the minimum for Solpuna followed by Swarna Sub 1 and Manohar Sali. The landrace Solpuna exhibited statistically at par performance with respect to seedling length and seedling vigour index under both the environments. Seedling vigour index proved to be a reliable character for desirable improvement in rice anaerobic germination and growth. Cluster analysis grouped Solpuna separately which might be due to its unique performance under anaerobic condition. Solpuna proved its superiority over the other nine genotypes in its ability to germinate and grow under anoxic condition. The present study further indicated that AG tolerance might be independent of the submergence tolerance at the vegetative stage conferred by SUB 1A gene or gene (s) with similar effects.