Difference in response to drought stress among Tibet wild barley genotypes

Abstract

Wild barley germplasms are a treasure trove of useful genes and provide rich sources of genetic variation for crop improvement. We carried out a hydroponic and pot evaluation of diverse germplasms in response to drought stress using 47 Tibet annual wild barley genotypes. Our results from the hydroponic experiment showed that SPAD (soilplant analyses development analyses, based on chlorophyll meter readings), plant height, and biomass of shoot/root were significantly reduced in plants exposed to drought stress (exposure of plant roots to air for 6 h daily for a period of 7 days) compared with control plants. There were significant differences among the 47 wild barley genotypes in terms of the reduction in these growth parameters, with variation coefficients and diversity indexes ranging from 23.2 to 49.1% and 1.46 to 1.62, respectively, suggesting a rich genetic diversity among the tested accessions. Genotypes XZ5 and XZ150 showed the least reduction, indicating their high tolerance to drought stress, while genotypes XZ54 and XZ147 showed the greatest reduction, and drought stress symptoms appeared rapidly and severely in these latter genotypes. The trends in the different responses of these genotypes to drought stress were fairly consistent in both the hydroponic and the two pot selection experiments, with XZ5 and XZ150 screened as drought-resistant genotypes and XZ54, XZ147 as drought-sensitive ones. Significant genotypic differences in leaf soluble sugar content and water use efficiency in response to drought stress were also observed in pot experiment two, with the droughttolerant genotype XZ5 showing a markedly higher recovery and the two drought-sensitive genotypes XZ54 and XZ147 showing a markedly lower recovery than the control plants.

QTL for Water Use Related Traits in Juvenile Barley

“…Limited biomass production under drought stress was detected in a lot of studies in barley in field experiments [41], greenhouse experiments [13,45] and hydroponics [14], and was also observed in different developmental stages [46]. In our studies, a significant effect of the treatments and genotypes and also significant interactions of genotypes and treatments were detected (Table 2), which are due to the large variability of the 156 genotypes analysed, and makes this set highly suitable for GWAS.…”

“…The actual amount of absorbed water, i.e., total leaf water (LW), can be measured by comparing fresh weight (FW) and dry weight (DW) of above ground biomass at a defined time point [13,14]. Other parameters are the leaf water content (WC), which is estimated in relation to dry weight, or the relative water content (RWC), based on the full turgid weight of leaves [15].…”

Variation in β-amylase activity and thermostability in Tibetan annual wild and cultivated barley genotypes

“…Recently, it was shown that wild barley contained special germplasm with high tolerance to abiotic stresses, such as salinity and drought (Zhao et al, 2010;Wu et al, 2011). The current study showed that Tibetan wild barleys have wide genetic variation in BAA and BAT.…”

Functional Genomics of Drought Tolerance in Crops: Engineering Transcriptional Regulators and Pathways

“…Wild relatives of major crops could be a starting point [70], although they have not been used extensively in conventional breeding. Drought tolerance has been identified in wild emmer (Triticum dicoccoides) [71], certain barley genotypes from Tibet [72], wild Oryza spp. and accessions of cultivated rice [73], and pearl millet (Pennisetum glaucum) [74].…”