SELECTION INDEX FOR GENETIC IMPROVEMENT IN WHEAT (Triticum aestivum L.)

Abstract

An experiment was conducted at the research field of the Department of Genetics and Plant Breeding with twenty four wheat genotypes collected from Wheat Research Centre, BARI, Dinajpur. The wheat genotypes were evaluated in randomized completely blocked design with three replications to study genotypic and phenotypic co-efficient of variation, heritability, genetic advance and selection index for genetic improvement of the selected wheat genotypes. The study results revealed that moderate heritability coupled with moderate genetic advance in thousand grain weight (g), number of grain per spike, plant height (cm) and days to heading. Among characters thousand grain weight had high genotypic and phenotypic co-efficient of variation over other characters. Yield per plant alone considered 100%, expected genetic grain and relative efficiency of other functions were calculated accordingly. Yield per plot (g) with thousand grain weight (g), number of grain per spike, number of spikelet per spike, days to anthesis, number of heading per days, and plant height (cm) association would be more efficient for improvement due to the maximum expected genetic gain (425.97) with maximum relative efficiency (122.75%) as found in selection index. But considering economic viability and practical condition, selection indices for the improvement of yield, the five character association i.e. yield per plot, thousand grain weight, number of grain per spike, number of spikelet per spike and days to anthesis per days is better than others is suggested. Comparison among relative selection criteria of all the characters of the studied wheat genotypes based on the best selection index yield per plot, thousand grain weight, number of grain per spike, number of spikelet per spike and days to anthesis (five character association), with total rank value besed on selection criteria the genotype PYT-15 is the promising genotype for genetic improvement.