Screening of Worldwide Barley Collection for Drought Tolerance: The Assessment of Various Physiological Measures as the Selection Criteria

Abstract

Drought is a devastating environmental constraint affecting the agronomic production of barley. To facilitate the breeding process, abundant germplasm resources and reliable evaluation systems to identify the true drought-tolerant barley genotypes are needed. In this study, 237 cultivated and 190 wild barley genotypes, originating from 28 countries, were screened for drought tolerance under the conditions of both water deficit and polyethylene glycol (PEG)-simulated drought at seedling stage. Drought stress significantly reduced the plant growth of all barley genotypes, but no significant difference in drought-induced reduction in the performance of barley seedlings was observed under these two drought conditions. Both cultivated and wild barley subspecies displayed considerable genotypic variability in drought tolerance, which underpinned the identification of 18 genotypes contrasting in drought tolerance. A comparative analysis of drought effects on biomass, water relation, photosynthesis, and osmotic adjustment was undertaken using these contrasting barley genotypes, in order to verify the reliability of the screening and to obtain the credible traits as screening criteria of drought tolerance in barley. As expected, the selected drought-tolerant genotypes showed much less reduction in shoot biomass than drought-sensitive ones under water deficit, which was significantly positively correlated with the results of large-scale screening, confirming the reliability of the screening for drought tolerance under two drought conditions in this study. Likewise, the traits of water relation, photosynthetic activity, and osmotic adjustment differed greatly between the contrasting genotypes under water deficit stress, and they were highly correlated to the growth of barley seedlings, suggesting the potential of them to be the selection criteria for drought tolerance. The analysis of the variable importance of these traits in drought tolerance indicated that sap osmolality and relative water content in the youngest fully-expanded leaf are the suitable selection criteria of screening for drought tolerance in barley at seedling stage.

Screening of Iraqi barley accessions under PEG-induced drought conditions

“…These results are in line with previous studies and provide further evidence of the suitability of PEG as a molecule for simulating droughts under in vitro conditions. These findings are like previous research and show the response to droughts depends on both genotypes and levels of stress (Almansouri et al 2001;Cai et al 2020).…”

Integration of Abandoned Lands in Sustainable Agriculture: The Case of Terraced Landscape Re-Cultivation in Mediterranean Island Conditions

“…Detailed meteorological data collected by the extensive network of the meteo-stations during the growing seasons (2018-2021), displayed a period of high precipitation on the island (October to early May), followed by a hot and dry period (June to September). Barley (Hordeum vulgare) landraces was selected for cultivation of abandoned terraces due to its significant drought tolerance compared to other cereals [51][52][53]. Notably barley landraces bear many desirable traits counting abiotic stress tolerance, nutrient use efficiency and crop quality characteristics, and therefore are excellent germplasm material for a low-input agriculture system [51].…”

A Wild Allele of Pyrroline-5-Carboxylate Synthase1 Leads to Proline Accumulation in Spikes and Leaves of Barley Contributing to Improved Performance Under Reduced Water Availability

“…This is associated with reduced dehydration and wilting under WS ( Delauney and Verma, 1993 ; Lee et al, 2009 ; Bandurska et al, 2017 ; Koenigshofer and Loeppert, 2019 ). In barley, Cai et al (2020) reported that genotypes that show less leaf wilting under stress were able to osmotically adjust and better tolerate water shortage. In our study P5cs1 -introgression lines showed less severe leaf wilting (−40%) under WS compared with elite counterparts, which indicates reduced susceptibility to soil drying conditions.…”