Marker Assisted Introgression of QTL (qDTY1.1) for Grain Yield under Drought at Reproductive Stage in Oryza sativa L. cv. Sita from Nagina -22

Abstract

Rice is the second major crop in the world in terms of area and production but due to change in environmental conditions, it is being affected by drought. Numerous rice varieties have been developed through conventional breeding method which takes a several years for its release and the varieties released Though this method may not be adequate to meet the future demand of growing populations. With the advancement of marker assisted breeding (MAB) along with the discovery of new QTLs, acted as a milestone in marker assisted introgression for development and release of variety. In the present research work emphasis has been given on introgression of QTL qDTY1.1 since it has been reported by researchers that it plays crucial role in drought tolerance which is located near to sd-1 gene. So, in the present investment, introgression of qDTY1.1 has been carried out from Nagina-22 in the background of local rice cultivar Sita. SSR marker RM431 was used for foreground selection while recombinant selection was carried out through RM3825 and RM12091. Background selection was performed with 49 polymorphic SSR markers. Maximum recovery obtained for BC2 F1 line was 79.59%. All positive BC2 F1 lines developed were subjected to further breeding and field trial. The results showed that Sita could be efficiently converted into a drought tolerant variety through backcross followed by selfing and selection, involving a time of two to three years. This approach demonstrates the effective use of marker assisted backcross breeding for introgression of qDTY1.1 in a molecular breeding programme.