ASSESSMENT OF SALINITY TOLERANCE BREAD WHEAT GENOTYPES: USING STRESS TOLERANCE INDICES

摘要

In the context, two field experiments were conducted at the Sakha Agriculture Research Station Farm in consecutive two years (2015-16 and 2016-17) under the normal and salinity stress conditions to find out the genotypes those are tolerance to salinity stress. Treatments were 24 bread wheat genotypes grown under the normal and salinity stress conditions. Among the genotypes 'Misr 2' vice versa in most conditions were recorded the maximum values of grain, straw and biological yields in both seasons. Results showed large values of broad sense heritability (h_b~2) were coupled with high values of genetic advance as a percent of mean (GA ) at 10 selection intensity for grain filling rate, spikes/m~2 and biological yield in both normal and salinity stress conditions. Already, the tested wheat genotypes exhibited different responses for stress (salinity) tolerance indices (STI). Near perfect and positive correlation coefficients (r=l) were found between three pairs of indices (STI and GMP), (YI and YS), (CVI and SSI) indicating that the two STI of each pair are identical for scatting genotypes for saline tolerance and they could be interchangeably used as a substitute for each other. The cluster analysis classified the tested genotypes into five main groups (clusters), where each group contained the genotypes that showed similar yield potential its components. The fifth cluster contained two promising genotypes namely 'lines 16' and 'Misr 2' that were characterized by high grain yield in each of the normal and salt soils, and also recorded the highest values of number of days to heading and maturity, plant height and spikes/m~2. Accordingly, Phenological variation as well as stress tolerance indices of these two wheat cultivars were found the favourable both under normal and salinity stress. Therefore, these two genotypes may be recommended to cultivate under the saline condition of Egypt and also may be used in the future breeding program to develop salinity tolerant wheat cultivars.