Selection Indices and Genetic Advance in Bread Wheat (Triticum aestivum L.)

Abstract

Twenty-five wheat (Triticum aestivum L.) genotypes were evaluated over two seasons in a 5x5 partially balanced lattice design. Data on five characters, namely number of fertile tillers/plant, number of spikelets/spike, number of grains/spike, 1000-grain weight and grain yield/plant were obtained. Then, different selection indices were constructed using different combinations of these characters. The smallest genetic advance (1.37 t/ha) and the lowest relative efficiency (40.92%) were recorded for the selection index based on number of fertile tillers/plant, number of spikelets/spike and number of grains/spike. Number of grains/spike,1000-grain weight and grain yield/plant showed the largest genetic advance (5.68/t/ha) and the highest relative efficiency (169.73%). The efficiency of a selection index was increased when either 1000-grain weight or number of grains/spike was added to, or replaced, another character in that index. Therefore, it could be concluded that number of grains/spike and1000-grain weight can be considered as reliable characters in selection for grain yield improvement.