Potentials of synthetic hexaploid wheats to improve drought tolerance

Abstract

Synthetic hexaploid wheat-derived lines (SHW-DL) offers new hope for breeders to restore genes lost during the evolutionary bottleneck. The study of adaptability, variation, and the possibility of selection in SHW-DL for drought tolerance is poorly understood in arid environments. The potential of 184 SHW-DL and their variation for agro-morphological traits were assessed under normal and water stress conditions for 2 years. The mean values of grain yield (YLD) varied from 683.9 g/m2 (water stress) to 992.1 g/m2 (normal conditions). Grain yield decreased by 64 and 71% under water stress in the two growing seasons. High genotypic variation was found for measured traits and drought tolerance. Heritability ranged from 19 (harvest index) to 47% (spike length), whereas grain yield indicated a moderate heritability (32%). Using the assessment of the interrelationship of traits, hectoliter (a quality trait) was correlated with drought tolerance and stability indices. Therefore, it can be considered as an important trait to select drought tolerant genotypes. In the following, the priority of yield components entering the regression model was different in two moisture conditions suggesting different strategies in indirect selection programs to improve yield. Spike m−2 and grain spike−1 indirectly and negatively affected yield through thousand-grain weight (TGW) under normal and water stress conditions, respectively. Furthermore, SHW-DL compared to ordinary wheat were significantly superior in terms of early maturity, dwarfing, yield, TGW, stem diameter, and harvest index. Overall, our findings suggest that SHW-DL are a valuable source for improving wheat yield and drought tolerance, and indirect selection might be possible to improve these complex traits.

Biochemical and phenological characterization of diverse wheats and their association with drought tolerance genes

“…Other than valuable agronomic and desirable quantitative traits, synthetic wheat has several potentials to improve drought tolerance of common wheat. Synthetic wheat has been reported to have significant genetic variation for drought stress resistance and thus are valuable sources of drought tolerance genes [ 32 – 34 ]. It has proven a good source of tolerance to Puccinia recondite [ 35 ], Puccinia striiformis [ 36 ], powdery mildew [ 37 ], and, tolerance to water stress [ 38 , 39 ].…”

A new winter wheat genetic resource harbours untapped diversity from synthetic hexaploid wheat.

“…The increased allelic richness and improvements in a range of target traits have driven the popularity of synthetic derivatives in breeding and variety release. These characteristics include: disease and pest resistance (Morgounov et al, 2018;Shamanin et al, 2019), drought tolerance (Mokhtari et al, 2022), heat stress (Cossani and Reynolds, 2015) and yield improvements (Jafarzadeh et al, 2016). However, their impact has been lower in areas that predominantly grow winter wheat under more intensive production systems, such as the United Kingdom (UK) and Northern Europe.…”

Breeding safflower for adaptation to autumn sowing by interspecific hybridization

“…Maintaining and increasing the agricultural production in the coming decades in a climate change scenario requires new approaches for the development of new crop varieties that are more tolerant to environmental stresses (Prohens et al., 2017). Cultivated species has gone through a genetic bottleneck experienced during domestication and evolved with a narrow genetic variation (Mokhtari et al., 2022). Compared to its two donor species, a considerable portion of original genetic diversity of safflower ( Carthamus tinctorius L.), as an oil and medicinal plant, has been lost.…”