A direct hybridization approach to gene transfer from Aegilops tauschii Coss. to Triticum aestivum L

Abstract

Aegilops tauschii Coss., the D-genome donor of bread wheat, represents a rich source of resistance and productivity traits for wheat improvement. In this study, a direct hybridization approach using Ae. tauschii as the female in crosses with Triticum aestivum resulted in about 50 times more F 1 plants than the reciprocal cross. In a set of five Ae. tauschii · T. aestivum crosses, an average of 35% of the pollinated florets resulted in embryo formation. Following embryo rescue on artificial medium, an average of 6.8 F 1 plants could be obtained for every 100 florets pollinated. Colchicine treatment of the F 1 plants greatly enhanced backcross seed formation (14.9 backcross seeds compared to an average of 0.47 seeds per 100 florets for untreated tillers). The efficacy of this gene transfer system was demonstrated by improved cell membrane stability and chlorophyll retention in BC 1 F 4 lines derived from the crosses of three heat-tolerant accessions of Ae. tauschii with bread wheat cultivar ÔPBW 550Õ.

Genotypic Variation and Genotype × Environment Interaction for Yield‐Related Traits in Synthetic Hexaploid Wheats under a Range of Optimal and Heat‐Stressed Environments

“…Ridge regression was used to remediate multicollinearity between variables to determine the ability of agronomic traits to predict GY in each individual environment, averaged across the NOR and HS environments and averaged across all the environments. Ridge regression was performed using the REG procedure with the ridge option in SAS (SAS Institute, 2007).…”

“…Few studies have reported on the performance of SHWs and their derivatives under heat stress, and most reports are limited to determination of superiority over their respective recurrent wheat parents (Sehgal et al, 2011; Sharma et al, 2014; Cossani and Reynolds, 2015). In this study, the performance of 137 SHWs was evaluated under timely and late sowing to identify genetic variation for important agronomic traits under heat stress.…”

“…Wild relatives of wheat are an important source of traits in breeding for resilience to weather extremes (Trethowan and Mujeeb-Kazi, 2008;Mujeeb-Kazi et al, 2013;Börner et al, 2015), including heat tolerance (Ehdaie and Waines, 1992;Khanna-Chopra and Viswanathan, 1999;Zaharieva et al, 2001;Pradhan et al, 2012). Sehgal et al (2011) reported that Aegilops tauschii Coss., the D genome donor of bread wheat, represents a rich source of disease resistance and productivity traits for wheat improvement. Furthermore, they demonstrated improved cell membrane stability and chlorophyll retention in BC 1 F 4 lines derived from the crosses of three heat-tolerant Ae.…”

Breeding Cultivars for Heat Stress Tolerance in Staple Food Crops

“…In wheat, Aegilops tauschii was successfully used as a donor for incorporating HT-relevant component traits such as cell membrane stability and chlorophyll retention into cv. PBW550 through backcrossing [122]. More recently, attempts were made in wheat aiming at introgression of wheat-Leymus racemosus chromosome to cv.…”

Heat stress in crop plants: its nature, impacts and integrated breeding strategies to improve heat tolerance

“…Recently, A. tauschii was successfully used as a donor for incorporating HT‐relevant component traits such as cell membrane stability and chlorophyll retention into cultivar ‘PBW550’ through backcrossing (Sehgal et al. ). Likewise, identification of A. speltoides Tausch and A. geniculata Roth species offering HS tolerance at reproductive stage opens up new opportunities for incorporation of HT genes in hexaploid wheat in near future (Pradhan et al.…”