Gene action and combining ability analysis of morpho- physiological attributes in spring wheat

Wheat (Triticum aestivum L.) is the most precious staple food and is highly regarded in the world as king of cereals. The present experiment was conducted to determine the gene action and combining ability analysis involving six high yielding lines of wheat (Triticum aestivum L.) viz., 9859, 9860, 9861, 9862, 9863 and 9864 and three testers Aas-11, Galaxy-13 and Punjab-11 which were crossed in line x tester mating design in the experimental area of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad. The parental genotypes and their F1 hybrids were examined in randomized complete block design (RCBD), with three replications under normal conditions in the season 2015-16. The data were collected for various economic plant attributes viz., plant height, flag leaf area, stomata size, stomata frequency, spike length, spikelets per spike, number of grains per spike, 1000-grain weight and grain yield per plant. The data were analyzed statistically and combining ability studies were done using line x tester analysis to find the relationship between different morpho-physiological traits of wheat. Highly significant differences were shown among the lines and testers for most of the traits. For flag leaf area, stomata size, stomata frequency, spike length, and grain yield per plant genotype 9859 proved to be good general combiner among the female parent, while the other female parent 9864 illustrated positive general combining ability for traits like plant height, number of grains per spike and 1000-grain weight. Among testers (males) Galaxy-13 exhibited positive general combining ability for the studied traits. Among the crosses, the hybrid 9864 x Galaxy-13 was the best specific combiner for most of the yield contributing traits. The GCA to SCA ratio suggested that Non-additive gene action was involved in the inheritance of most of the traits like flag leaf area, stomata size, stomata frequency, spike length, number of grains per spike, 1000-grain weight and grain yield/plant. In this case hybrid breeding may be suggested and it will be more useful. Additive gene action was involved in the inheritance of plant height and number of spikelets per spike, therefore selection will be useful in early segregating generation of above mentioned traits. The superior genotypes and crosses can be combined ·to develop new promising and improved wheat varieties for obtaining high yield.