Genetic divergence and selection parameters in basmati rice

Abstract

The research project 'Genetic divergence and selection parameters in Basmati rice was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'97. The major objectives of the study were to study the genetic divergence among advanced breeding lines of Basmati rice evolved at various rice research centres in India and to select high yielding quality Basmati rice genotypes adopted to Kerala ecosystem. The study, about components of heritable variation revealed that the range of variation is high for height of plant at harvest, total number of tillers, numbers of panicle bearing tillers, number of panicles/ m2 , number of spikelets/panicle, pubescence, awnness, num- ber of grains/panicle, aroma, overall acceptability, amylose content, kernel elongation after cooking, elongation ratio and yield. Heritability studies revealed that pH of raw grain, LIB ratio, kernel breadth and taste showed the maximum broad sense heritability among the qualitative characters; number of days to panicle initiation also had high heritability among the quantitative characters. Cluster analysis revealed that there was no parallelism between geographical distribu- tion and genetic diversity. The 38 genotypes were grouped into seven clusters. Correlation studies revealed that the principal yield determining components in Basmati rice are number of days to panicle initiation, number of days to 50% flowering, height of plant at harvest, number of panicle bearing tillers, number of paniclesl/m2 ,1000 grain weight, aroma, kernel length before and after cooking, alkali value and awnness. While selecting genotypes for higher yield potential, emphasis should be given for compara- tively long vegetative period, short period from panicle initiation to 50 percent flower- ing and dwarf plant type.

A selection model was formulated consisting of the characters namely. Yield/ha, num- ber of days to panicle initiation, height of plant at harvest, number of panicles/m2 , alkali value and elongation ratio. Basmati culture 385 and UPR-BS-92-4 are identified as superior genotypes among the entries studied.