Response of Cultivated and Wild Barley Germplasm to Drought Stress at Different Developmental Stages

Abstract

Little is known about response of root‐related traits of barley (Hordeum vulgare L. subsp. vulgare; hereafter, Hvu) and its wild relative H. vulgare L. subsp. spontaneum (K. Koch) Thell. (hereafter, Hsp) to drought stress. Three separate experiments were conducted to assess these traits at germination, vegetative, and reproductive stages. Drought stress significantly reduced germination percentage and rate, primary root number, and shoot and root length of seedlings. Using pot experiment, drought stress reduced shoot dry weight (SDW) and root dry weight (RDW) at vegetative stage but the ratio of RDW/SDW (RSR) increased under this condition. At reproductive stage, SDW, plant height, number of fertile tiller, and relative water content decreased under drought stress, but root length, root volume, RDW, and RSR increased as the intensity of drought increased. For most of the traits the genotype × moisture environment interaction was significant. The effect of drought stress on genotypes was highly dependent to developmental stages and the intensity of water limitation. The wild barley genotypes had more drought tolerance than the cultivated ones. The results of vegetative and reproductive stages poorly matched with the ones from seed germination stage. Two wild barley genotypes from Iran were tolerant to drought stress at both vegetative and reproductive stages and may be used for genetic studies and possible breeding of barley for root‐related traits.

Potential of Iranian wild barley (Hordeum vulgare ssp. spontaneum) in breeding for drought tolerance

“…However, by all of these methods, most of the drought tolerant genotypes were from the WB group. Similar results have been reported in previous studies of root-related traits (Barati et al 2015), which most of genotypes with vigorous root system (higher root dry weight, depth and area) were from the wild barley accessions. In the other study on wild barley species, the genotypes from H. murinum and H. marinum had more yield stability on drought stressed environment compared to the cultivated one (Barati et al 2018).…”

“…Therefore, a much fuller exploitation of these genetic resources by breeding for economically important agronomic traits is warranted. Barati et al (2015) also evaluated the root characteristics of a cultivated and WB germplasm, mostly originated from Iran, and identified genotypes with high drought tolerance at each developmental stage based on root-related traits. In a recent study, Barati et al (2018) evaluated agro-morphological and yield-related traits associated with drought tolerance in 80 barley genotypes belonging to 15 wild species and identified wild barley genotypes with favorable characteristics and high drought tolerance.…”

Genome-Wide Association Mapping in the Global Diversity Set Reveals New QTL Controlling Root System and Related Shoot Variation in Barley

“…For this, we focused primarily the root trait variation, to find major genetic players contributing to different root systems in barley and secondly to dissect the putative genetic interplay of root and shoot traits. It has been reported that the root architecture takes major role in plant adaptation to drought (Chloupek et al, 2010; Wasson et al, 2012; Barati et al, 2015). Although, numerous GWAS studies have been made on barley diversity analysis by Nandha and Singh (2014) and Russell et al (2014), but genetic dissection of root traits remained fragmented due to difficulty for its phenotypic evaluations.…”

Soil Water Effect on Root Activity, Root Weight Density, and Grain Yield in Winter Wheat

“…Table 1 shows the significant effect of growth stage, soil water content, and soil layer on wheat root weight density in these experiments ( P < 0.01). Similarly, Barati et al (2015) revealed that the effect of drought stress on genotypes was highly dependent on developmental stage and the intensity of water limitations. Moreover, Guan et al (2015) investigated the root weight density of wheat at tillering, flowering and ripening, revealing a maximum value at flowering.…”