Abstract

                                Investigation was carried out with an objective of studying the genetic architecture of biparental progenies (BIPs) of JGL 384 x Rasi cross combination of rice in terms of grain quality parameters. Intermated progenies (BIPs) showed superior mean performance than their parents, F1 , F2 and F 3 generations for hulling (76.24%), milling (72.24%), head rice recovery (67.48%), kernel length after cooking (9.78), kernel L / B ratio after cooking (3.08), linear elongation ratio (1.66), volume expansion ratio (4.94) and amylose content (22.64%). Enhanced trait mean value might be due to pooling of favorable alleles through recombination, considerable heterozygosity, accumulation of favorable alleles of low frequency and breaking up of undesirable linkages which was possible because of intermating. Combining ability analysis of NCD II revealed that cooking traits like kernel length after cooking and volume expansion ratio were governed by additive genes. Hence, for the improvement of these traits pure line selection, mass selection and or progeny selection will be suggested and selection might be effective at this level. Other grain quality traits viz., hulling percentage, milling percentage, head rice recovery, kernel length, kernel breadth, kernel L/B ratio, kernel breadth after cooking, kernel L/B ratio after cooking, linear elongation ratio, breadth wise expansion ratio, gel consistency, gelatinization temperature and amylose content were governed by dominant genes. Hence, these traits could be improved by recombination breeding by taking up selection at later generations, alternatively one or two more cycles of intermating may break the undesirable linkages among the traits of interest.

Key words : Biparental mating, NCD II, Rice grain quality