A Single Locus Is Responsible for Salinity Tolerance in a Chinese Landrace Barley (Hordeum vulgare L.)

Abstract

IntroductionSalinity and waterlogging are two major abiotic stresses severely limiting barley production. The lack of a reliable screening method makes it very hard to improve the tolerance through breeding programs.MethodsThis work used 188 DH lines from a cross between a Chinese landrace variety, TX9425 (waterlogging and salinity tolerant), and a Japanese malting barley, Naso Nijo (waterlogging and salinity sensitive), to identify QTLs associated with the tolerance.ResultsFour QTLs were found for waterlogging tolerance. The salinity tolerance was evaluated with both a hydroponic system and in potting mixture. In the trial with potting mixture, only one major QTL was identified to associate with salinity tolerance. This QTL explained nearly 50% of the phenotypic variation, which makes it possible for further fine mapping and cloning of the gene. This QTL was also identified in the hydroponic experiment for different salt-related traits. The position of this QTL was located at a similar position to one of the major QTLs for waterlogging tolerance, indicating the possibility of similar mechanisms controlling both waterlogging and salinity tolerance.ConclusionThe markers associated with the QTL provided a unique opportunity in breeding programs for selection of salinity and waterlogging tolerance.

Ability of leaf mesophyll to retain potassium correlates with salinity tolerance in wheat and barley

“…Among wheats, bread wheat variety Kharchia and durum wheat variety Wollaroi were previously reported as being tolerant, while Baart and Tamaroi were sensitive to salt (Cuin et al ). Among barley varieties, CM72 and TX9425 were deemed tolerant, while Gairdner and Naso Nijo were highly sensitive (Chen et al , Xu et al ). Salt tolerance was defined as a genotype's ability to maintain biomass growth and grain yield under saline conditions and was correlated with better K + /Na + in the shoot, both in wheat (Cuin et al ) and barley (Chen et al , ).…”

“…This also poses a question of what specific trait should be used to identify the source of salt tolerance genes to be used in marker‐assisted selection (MAS)‐based breeding programs. Various agronomic traits such as germination, survival and growth rates, the extent of leaf injury, biomass production (Mano and Takeda , Eleuch et al , Xu et al , Zhou et al ) and whole‐plant physiological characteristics such as CO 2 assimilation, chlorophyll content, shoot Na + and K + content (James et al , Chen et al , Munns et al ) have been frequently advocated. To a large extent, the choice has been determined by the convenience (e.g.…”

QTLs for stomatal and photosynthetic traits related to salinity tolerance in barley

“…Salinity tolerance score, assessed through the combination of plant survival and leaf wilting, has been used for evaluating barley salt tolerance in our previous studies [35, 38, 54]. Crop yield under salinity stress is a result of balancing resource allocation between growth and defence against stress, since responding to stress is deleterious to growth and yield [55]; therefore, the ability to produce high grain yield in saline soils is the ultimate criterion of salinity tolerance.…”

“…Using various genetic populations, some QTLs for salinity tolerance in barley have been found and are associated with chlorophyll content, chlorophyll fluorescence, proline content, water soluble carbohydrates, relative water content [56], ion content [57, 58], and salinity tolerance [35, 38, 54, 59]. Previous QTL studies of barley salinity tolerance have lacked information on the genetic mechanisms underlying stomatal traits and gas exchange parameters.…”

“…Salt tolerance score was assessed at the seedling stage by combining scores for leaf chlorosis and plant survival (0 = no damage and 10 = all dead) when the most susceptible lines showed severe symptoms [38]. In this study, salt tolerance evaluation was based on the average value from results obtained in 2010, 2014 and 2015 in Launceston, Australia.…”