MSc

The research project entitled “Identification of restorers for hybrid rice technology through molecular marker aided selection” was carried out in the department of Plant Breeding and Genetics ,College of Agriculture,Vellayani during the year 20010-11.
The major objectives of this study was to Compare the morphological characters of the genotypes with the known restorers and to study the allelic status of the Kerala varieties with respect to SSR markers linked to Rf loci. This study also intended to assess the possibility for using Marker Assisted Selection for screening for restorers. The study was under taken in 19 rice varieties released by KAU and two restorers used in hybrid rice technology in Tamil Nadu Agricultural University.
Biometrical analysis showed the varieties Aiswarya,Neeraja,Ptb2,Ptb13,Varsha,Swarna Prabha and Kanchana are having characters similar to the fertility characters of the known restorers . All the SSR markers selected in the study showed amplification in all the genotypes .The SSR markers, RM258, RM228, RM6100, RM6344 and RM171 showed polymorphism in the profile. SSR marker RM228 mapped on chromosome 10 and linked to Rf4 gene produced three alleles at the loci between 100-200 bp. SSR marker RM 258 mapped on chromosome 10 and linked to Rf -4 ,Rf 5 and Rf (u1)genes produced three alleles but only one of them was present in both the known restorers. SSR marker RM6100 mapped on chromosome 10 and linked to Rf4 gene produced three alleles.SSR marker RM171 on chromosome 10 linked to Rf 4 gene produced two alleles between 100-200bp. SSR marker RM6344 located on chromosome 7 and linked to Rf 4 locus produced three alleles between 100-200bp
Among the five SSR markers tested in this study RM171 and RM 6100 showed a comparatively better performance in screening restorers. The dendrogram constructed with data from the amplification profile of different primer pairs show that the varieties Varsha and Neeraja with close similarity with Co48 and CB87R with respect to Rf locus. The dendrogram based on the fertility traits also clustered Varsha and Neeraja along with Co48 and CB87R. Ptb-10 and Aiswarya are on par with each other both were reported as maintainers. Members of these two clusters can be used to develop maintainers and restorers respectively.
Most of the restorers so far reported are white kernelled and a probable linkage between white kernel colour and Rf loci was reported in this study also Neeraja which showed tight linkage with Co 48 the known restorer is a white kernelled variety. However Manupriya and Varsha which also showed close similarity with the known restorers are red kernelled varieties. Keralites are very specific in the quality of rice they consume. A red kernelled bold grain with non stickiness after cooking is preferred mostly. The red varieties Varsha and Manupriya can be tested for their restoring ability and can be used for the development of restorers with specific quality requirements of Kerala and there by superior hybrid which can break the yield plateau of the high yielding varieties can be released