Introgression of yellow stem borer (Scirpophaga incertulus) resistance genes into cultivated rice (Oryza sp.) from wild species

Abstract

Wild rice germplasm has been screened against yellow stem borer (Scirpophaga incertulas L.) and O. brachyantha, O. officinalis, O. ridleyi and Porteresia coarctata were found to be resistant/tolerant. It is essential to introgress these resistance genes from wild species to cultivated rice for the development of rice varieties with in-built resistance against yellow stem borer. The BC1F1 inter-specific hybrid of O. sativa cv ‘Savitri’/O.brachyantha was backcrossed with recurrent parent ‘Savitri’ employing embryo rescue technique. The morphological characters of the embryo rescued plants were studied and they were observed to be phenotypically different types, namely grassy, bushy, erect, dwarf, sterile and pseudonormal etc. The morphology of the chromosome variants was observed to be different due to addition of different chromosome numbers. The cytological analysis of the variants was done to identify the different chromosome variants for the development of monosomic alien addition lines to introgress yellow stem borer resistance genes to cultivated rice.