Salinity indices and path analysis in Egyptian long-staple cotton cultivars

Abstract

Soil salinity is one of the serious abiotic stresses adversely affects crop production. The objectives of this study were to screen fifteen long-staple cotton belong to Gossypium barbadense L. for salinity tolerance, salinity indices, genotypic correlations, and path-coefficient analysis. Under normal soil the genotypes differed significantly in most traits in both years. Under saline soil the differences among genotypes re significant in one year and in the combined analysis for SCY/P, LY/P, SI, NS/B, PH, and Pressley index. The cultivars “G 90 x Aus”, G95, G 90, G 80, and G 83 showed the highest performance in SCY/P, LY/P, Lint%, NB/P and NS/B either under normal or saline soil. The reduction% caused by salinity was observed for PH (55.92%), LY/P (52.21%), SCY/P (48 75%), NB/P (32.47%), LI (5.68%), Micronaire reading (11.22%), Pressley index (6.63%) and UHM length (0.89%). Giz90 x Aus followed by Giza 90 showed the best tolerance to salinity stress. The STI, MP, GMP, HM and DI detected both of tolerant and susceptible genotypes and could be considered the best tolerant indices. The direct and indirect effects of SCY/P components varied greatly under both environments. The direct effects of the SCY/P components under normal soil were 0.504, 0.401, 0.153 and 0.147 for NB/P, LY/P, SI, and NS/B, respectively. However, under saline soil the direct effects were 0.802, 0.178, 0.128 and 0.050 for LY/P, NB/P, NS/B and SI, respectively. Therefore, under both environments, selection should be paid mainly on NB/P and LY/P.