Physiological characterization of Turkish bread wheat genotypes for resistance to late drought stress

Authors : Ali ÖZTÜRK, Murat AYDIN

Pages : 414-440

View : 13 | Download : 7

Publication Date : 2017-12-01

Article Type : Research Paper

Abstract :A number of physiological traits have been proposed as selection criteria for late drought resistance and grain yield improvement in wheat. To characterize them in terms of late drought resistance, 64 bread wheat genotypes were evaluated for canopy temperature difference insert ignore into journalissuearticles values(CTD);, leaf senescence rate insert ignore into journalissuearticles values(LSR);, SPAD chlorophyll value, initial fluorescence insert ignore into journalissuearticles values(Fo);, maximum fluorescence insert ignore into journalissuearticles values(Fm);, variable fluorescence insert ignore into journalissuearticles values(Fv);, maximum quantum efficiency of PSII insert ignore into journalissuearticles values(Fv/Fm);, leaf ash content, and grain ash content in two field experiments conducted in irrigated and late drought conditions during the 2011-12 and 2012-13 seasons in Erzurum, Turkey. The experiments were conducted in an 8 x 8 lattice design with two replicates. Significant variation was observed among the genotypes for all the traits. Late drought decreased the grain yield, CTD, SPAD, Fm, Fv, Fv/Fm, and leaf ash content but increased LSR and grain ash content. The drought sensitivity of the genotypes was determined by a ranking method based on 25 traits measured in the late drought conditions. According to the rank-sum insert ignore into journalissuearticles values(RS); values of the genotypes, four genotypes were defined as resistant, 15 genotypes as medium resistant, 34 genotypes as medium sensitive, and 11 genotypes as sensitive. Resistant genotypes M?fitbey and Dağdaş 94 produced the highest grain yields in late drought conditions and appeared to be promising parents for the breeding of resistant cultivars. RS was negatively correlated with CTD, SPAD, Fm, Fv, and Fv/Fm, while it was positively correlated with LSR. For screening late drought-resistant genotypes, 15 days post anthesis insert ignore into journalissuearticles values(15DPA); is the optimum time for Fv, CTD, and SPAD measurements. The stepwise multiple linear regression analysis indicated that the Fv15DPA, Fv25DPA, CTD15DPA, and SPAD15DPA could explain 75.2% of the total variation in RS. Therefore, the Fv15DPA, Fv25DPA, CTD15DPA, and SPAD15DPA traits can be used as selection criteria as a combination for the classifying of wheat genotypes in terms of late drought resistance.
Keywords : Ash content, canopy temperature, chlorophyll, chlorophyll fluorescence, leaf senescence, ranking method