Genetic behavior of morpho-physiological traits in different generations of wheat under normal and water deficit environments

Abstract

The present study was designed by keeping in view the future scenario of increasing demand of wheat and decreasing resources especially irrigation water which is the most important of all the inputs. Hundred wheat accession were screened for relative water content and relative water loss of excised leaf. Based on the screening results two crosses and their generations P1, P2, F1, F2, BC1 and BC2 were developed among the contrasting parents for each of these traits. Further research was carried out to un-reveal the gene action of various yield and drought related traits using six wheat generations in field conditions under normal irrigation and water stress conditions. The relative water loss of excised leaf appeared as a better screening parameter for drought tolerance because the generations developed on the basis of this parameter performed better under drought for almost all the morpho-physiological traits. Conventional biometrical breeding methods were used to un-reveal the inheritance of chlorophyll ‘a’, chlorophyll ‘b’, leaf carotenoids, leaf water potential, leaf osmotic potential, leaf turgor potential at vegetative stage and plant height, number of tillers, flag leaf area, flag leaf weight, number of spikelets per spike, grain weight per spike, grain filling period, canopy temperature and grain yield per plant at maturity. Almost all the traits showed additive and non-additive (epistatic and dominant) nature of gene control except canopy temperature, leaf weight and turgor potential which were controlled by simple additive gene action which was further supported by high heritability. Overall less epistatic effects were observed in physiological traits as compared to yield and yield component traits which indicated that these traits can be manipulated comparatively easily for tailoring drought tolerant cultivars, the correlation results also supported these findings by showing their positive association with grain yield. The accession 8126 is suggested to be used in wheat breeding program to tailor drought resistance in the crop.