Applicability of Aegilops tauschii drought tolerance traits to breeding of hexaploid wheat

Abstract

Few genes are available to develop drought-tolerant bread wheat (Triticum aestivum L.) cultivars. One way to enhance bread wheat’s genetic diversity would be to take advantage of the diversity of wild species by creating synthetic hexaploid wheat (SW) with the genomic constitution of bread wheat. In this study, we compared the expression of traits encoded at different ploidy levels and evaluated the applicability of Aegilops tauschii drought-related traits using 33 Ae. tauschii accessions along with their corresponding SW lines under well-watered and drought conditions. We found wide variation in Ae. tauschii, and even wider variation in the SW lines. Some SW lines were more drought-tolerant than the standard cultivar Cham 6. Aegilops tauschii from some regions gave better performing SW lines. The traits of Ae. tauschii were not significantly correlated with their corresponding SW lines, indicating that the traits expressed in wild diploid relatives of wheat may not predict the traits that will be expressed in SW lines derived from them. We suggest that, regardless of the adaptability and performance of the Ae. tauschii under drought, production of SW could probably result in genotypes with enhanced trait expression due to gene interactions, and that the traits of the synthetic should be evaluated in hexaploid level.

Assessment of D-genome Based Genetic Diversity in Drought Tolerant Wheat Germplasm

“…tauschii has the least diversity (Dubcovsky and Dvorak, 2007) there by acts as a potential barrier for its improvement. The availability of few genes for developing drought tolerant wheat cultivars has compelled the wheat breeders to use the genetic diversity of wild species to achieve their goals (Sohail et al, 2011). In this regard Ae.…”

“…Conventional breeding approaches has little affect because drought tolerance is a quantitative trait and through selection high level of heritability is needed for the improvement of yield under such circumstances (Sohail et al, 2011). So among other approaches for wheat improvement the use of wild relatives as a source of rich genetic variation has significantly triggered the process (Ashraf, 2010).…”

“…Although SH do not possess superior good agronomic traits like modern wheat cultivars the genetic variability of the Ae. tauschii accessions has attracted most of the wheat breeders searching for allelic diversity for drought tolerance (Sohail et al, 2011). In these synthetic hexaploids, Ae.…”

Broadening the Genetic Diversity of Common and Durum Wheat for Abiotic Stress Tolerance Breeding

“…The growth performance of the parental Ae. tauschii accessions and their derivative SHWs was then compared (Table 25.1 ; Sohail et al 2011 ). Under well-watered conditions, intercellular CO 2 , transpiration rate, root dry weight and water use effi ciency were signifi cantly correlated in both diploid and hexaploid plants.…”

Genetic Characterization of Genetic Resources of <i>Aegilops tauschii</i>, Wheat D Genome Donor, Newly Collected in North Caucasia

“…Several studies revealed the high level of genetic diversity of Ae. tauschii regarding several useful traits, i.e., seed storage protein [4], flowering time [5], disease resistance [6] and biotic and abiotic stress tolerance [7] [8], suggesting the usefulness for improvement of wheat production.…”