Physio-Molecular approach towards developing rice variety for dual resistance (Drought and Submergence) under rainfed lowland ecosystem

Abstract

Crop in Rainfed lowland ecosystem often suffers both drought and/or submergence (either initial or last phase of life cycle) sometime in same life cycle depending upon prevalent weather in their region. Rice is more prone to this leading very poor or no yield. In the present study, one of promising IRRI rice lines NDR 9830102 was evaluated for drought and submergence. Swarna sub 1 and Jalmagna was taken as positive control for submergence and Nagina 22 as positive control for drought. Swarna and Mahsuri were also evaluated in both conditions. For drought observation were recorded on leaf rolling, relative water content and proline content while for submergence observation were recorded plant height, shoot elongation, survival% and carbohydrate content. Experimental results after desubmergence revealed that the NDR 9830102, Jalmagna had maximum shoot elongation followed by Swarna, Mahsuri while Swarna sub 1 had minimum shoot elongation. Swarna, Mahsuri, NDR 9830102 had minimum survival% and carbohydrate accumulation while Swarna sub 1 and Jalmagna had maximum survival%, carbohydrate accumulation. Under drought condition accumulation of proline were recorded maximum in Nagina 22 followed by NDR 9830102, Swarna and Swarna sub 1. Genetic diversity analysis by SDS-PAGE reveals that the genotype Swarna, Swarna sub 1 and NDR 98102 showed remarkable variation among each other. Seeing the promising dual tolerance in NDR 9830102, crosses were made between Swarna sub1 x NDR 9830102 and their F1 was tested through RAPD marker (OPA 11).