Breeding strategy for improvement of rice maintainer lines through composite population for short term diversity

Abstract

Hybrids commercially grown in the country gives 15-20% yield advantage over the best inbred varieties. There is a need to increase the magnitude of heterosis level to 20-30% besides improving grain quality and other desirable traits like plant type, number of productive tillers, flowering duration, desirable plant height, grain type, yield, maintenance ability, disease and insect pest resistance etc. In present study we developed base composite populations suitable to local conditions using original gene pool obtained from International Rice Research Institute (IRRI) by adding 10 component lines for above mentioned different traits. More than 950 productive segregants selections were made and stabilized through pedigree method for desirable traits. The developed lines are superior for different traits. This indicates population improvement strategy is bringing the superior allele into one line in short period of time from different genotypes. This method is very useful to increase diversity in hybrid rice parental lines within known time