Identification of variation in adaptively important traits and genome-wide analysis of trait–marker associations in Triticum monococcum

Abstract

Einkorn wheat Triticum monococcum (2n=2x=14, A(m)A(m)) is one of the earliest domesticated crops. However, it was abandoned for cultivation before the Bronze Age and has infrequently been used in wheat breeding. Little is known about the genetic variation in adaptively important biological traits in T. monococcum. A collection of 30 accessions of diverse geographic origins were characterized for phenotypic variation in various agro-morphological traits including grain storage proteins and endosperm texture, nucleotide-binding site (NBS) domain profiles of resistance (R) genes and resistance gene analogues (RGAs), and germination under salt and drought stresses. Forty-six SSR (single sequence repeat) markers from bread wheat (T. aestivum, 2n=6x=42, AABBDD) A genome were used to establish trait-marker associations using linear mixed models. Multiple significant associations were identified, some of which were on chromosomal regions containing previously known genetic loci. It is concluded that T. monococcum possesses large genetic diversity in multiple traits. The findings also indicate that the efficiency of association mapping is much higher in T. monococcum than in other plant species. The use of T. monococcum as a reference species for wheat functional genomics is discussed.

Triticum monococcumlines with distinct metabolic phenotypes and phloem-based partial resistance to the bird cherry-oat aphidRhopalosiphum padi

“…Triticum monococcum (L.) lines, in particular, have shown evidence of complete or partial resistance to pathogens and aphids (Spiller & Llewellyn, 1986; Migui & Lamb, 2004; Jing et al , 2007; Elek et al , 2012). Although seldom planted or harvested today, domesticated T. monococcum was an agriculturally important crop in the Neolithic through to the Bronze Age (Salamini et al , 2002).…”

“…The chromosomes of Triticum species, such as T. monococcum, pair well with the ‘A genome’ of T. aestivum potentially allowing introgression of genes from the wild wheats into cultivated species by recombining homologous chromosomes (Valkoun, 2001). It is believed that further genetic improvements to hexaploid wheats may therefore be found by exploring the genetic diversity within T. monococcum and discovering new allele variants (Jing et al , 2007). …”

Association genetics of carbon isotope discrimination, height and foliar nitrogen in a natural population of Pinus taeda L

“…Both candidate gene and genome-wide approaches are potentially successful methods for the discovery of variants that are either causal, or are linked to, the causal variant for disease and quantitative traits (Hirschhorn and Daly, 2005). Association studies for herbaceous plants have been successful in identifying polymorphisms related to phenotypic variation in adaptive traits in Arabidopsis (Chan et al, 2010), as well as economically important traits in maize (Buckler et al, 2009), sugar beet (Stich et al, 2008b) and wheat (Jing et al, 2007).…”

Interactions between leaf pubescence genes in bread wheat as assessed by high throughput phenotyping

“…Monogenically inherited leaf hairiness was Euphytica showed in diploid wheat T. monococcum (Sharma and Waines 1994). In another study, leaf pubescence of this species was mapped to 5A m L chromosome as a QTL (Jing et al 2007). For bread wheat, besides genes mentioned here, additional loci were detected in chromosomes 7A (Shahinnia et al 2013) and 7D (Doroshkov et al 2014).…”