Morphological and physiological traits of triticale as affected by drought stress

Dan Yang1, Shuyun Zhang1, Xinhui Tian1, and Wenhua Du1*
Triticale (×Triticosecale Wittm.) is a major forage crop of arid and semiarid areas in China with yields much constrained by drought stress. Genetic improvement could benefit from a better understanding of drought effects on plant morphology and physiology. In this study, the morphophysiological traits of four triticale genotypes (line C31, varieties ‘Gannong No.1’, ‘Gannong No.2’, and ‘Shida No.1’) were determined on days 7, 14, 21, 35, 49, and 63 for treatments of the normal irrigation and drought stress, respectively. Rainfall of the drought stress treatments was controlled during the study using an anti-rain shed. Our findings suggest that drought stress had significant effects on all morphophysiological traits except for the relative number of leaves (RL) and catalase activities (RCAT). Among four genotypes, the averaged relative plant height (RH) of ‘Gannong No.2’ (0.90) was the highest, the averaged relative number of tillers (RT) of ‘Gannong No.1’ (0.77) was the highest, the averaged relative aboveground biomass yields (RAB) (0.53), relative leaf water content (RRWC) (0.96), and peroxidase activity (RPOD) (0.92) of C31 were the highest, respectively, and the averaged RCAT (1.06) of ‘Shida No.1’ was the highest. The interaction between genotype and drought stress days was significant for all morphophysiological traits except for the RT and RL. A comprehensive evaluation revealed that C31 was the most drought-tolerant genotype under persistent drought stress. These findings may be useful for the breeding and identification of drought-tolerant germplasms in the arid and semi-arid regions.
Keywords: Comprehensive evaluation, drought tolerance, morphophysiological traits, relative values, ×Triticosecale
1Gansu Agricultural University; College of Grassland Science, Grassland Ecosystem Key Laboratory of Ministry of Education; Si-no-U.S. Research Centers for Sustainable Grassland and Livestock Management, Lanzhou, Gansu Province 730070, China.
*Corresponding author (duwh@gsau.edu.cn).