Drought and salt tolerances in wild relatives for wheat and barley improvement

Abstract

Drought and salinity are the major abiotic stresses that dramatically threaten the food supply in the world. Tribe Triticeae, including wheat and barley, possesses tremendous potential for drought and salt tolerance that has been extensively and practically identified, tested, and transferred to wheat cultivars with proven expression of tolerance in experimental trials. Triticum dicoccoides and Hordeum spontaneum, the progenitors of cultivated wheat and barley, have adapted to a broad range of environments and developed rich genetic diversities for drought and salt tolerances. Drought-and salt-tolerant genes and quantitative trait loci (QTLs) have been identified in T. dicoccoides and H. spontaneum and have great potential in wheat and barley improvement. Advanced backcross QTL analysis, the introgression libraries based on wild wheat and wild barley as donors, and positional cloning of natural QTLs will play prevailing roles in elucidating the molecular control of drought and salt tolerance. Combining tolerant genes and QTLs in crop breeding programs aimed at improving tolerance to drought and salinity will be achieved within a multidisciplinary context. Wild genetic resistances to drought and salinity will be shifted in the future from field experiments to the farmer.

Root precursors of microRNAs in wild emmer and modern wheats show major differences in response to drought stress

“…dicoccoides, is an allotetraploid with direct ancestry to bread and durum wheats. It is, thus, capable of producing fertile offspring with either species which potentiates its utilization in breeding studies (Xie and Nevo 2008;Nevo and Chen 2010). Recently, screening of a panel of 200 Turkey-originating wild Bala Ani Akpinar and Melda Kantar contributed equally to this work.…”

“…Domestication has considerably reduced the genetic diversity in cultivated wheat species, which is exacerbated by several years of agricultural practices selecting plants for uniformity and high yields. Conversely, wild populations and landraces adapted to a wide range of environments exhibit extensive genetic diversity, which can be utilized as a rich source for favorable alleles, especially for stress tolerance (Nevo and Chen 2010;Budak et al 2013a). To explore and exploit these natural resources for the development of drought-tolerant varieties, a thorough understanding of the complex drought stress response and adaptation mechanisms at the physiological and molecular level is crucial (Kantar et al 2011a;Akpinar et al 2012Akpinar et al , 2013.…”

Screening for root and shoot traits in different wheat species and wild wheat relatives

“…Ancient wheats such as einkorn, emmer and Khorasan wheat all have higher contents of the carotenoid lutein than bread wheat (Shewry & Hey 2015). The genetic diversity confers the variations in drought and salt tolerance in the wild wheats and wheat relatives (Nevo & Chen 2010). Therefore, further studies should be performed on root and shoot traits of wheat landraces, wild wheats and wheat relatives, which contribute to increases in productivity and quality of improved crops.…”

Molecular and Phenotypic Characterization of Advanced Backcross Lines Derived from Interspecific Hybridization of Durum Wheat

“…Alien introgression is considered to be a useful tool for enriching the genetic diversity by introducing new traits and for germplasm development (29,63). Obtaining ample collections of monosomic substitution and deletion lines of wheat is a key objective for cytogeneticists as well as geneticists.…”