Characterization and utilization of currently grown Turkish wheat landraces

Abstract

From 2009 to 2014 a nationwide effort was made to document, collect, conserve, characterize and utilize wheat landraces grown by Turkish farmers. Altogether 95 morphotypes were identified representing three species and six subspecies: Triticum monococcum, T. turgidum ssp. dicoccon, T. turgidum ssp. turgidum, T. turgidum ssp. durum, T. aestivum ssp. aestivum, and T. aestivum ssp. compactum (Morgounov et al. 2016). Spike samples were collected from more than 1,600 farmers from 59 provinces, planted as single-spike progenies and, consequently, evaluated for diseases, agronomic traits and grain yield in replicated trials at multiple sites within the country. Overall 2000 lines originating from landraces were evaluated in yield trials from 2012 till 2016. Superior landrace selections have been identified for yield potential, drought tolerance, resistance to rusts, grain quality and many other traits. Simple selections from the landraces, even morphologically uniform, allow achieving substantial genetic gains for the traits valued by farmers. Bread wheat lines were characterized for genetic diversity using 63 KASP-SNP markers resulting in 28 clusters. The clusters differed in geographic origin, morphology and agronomic traits and served as a basis for selection of the core set for future detailed characterization. A set of 153 landrace selections tested at 3 sites in 2013 was subjected to genome wide association analyses which confirmed some known associations (previously reported QTLs) as well as identified new candidate genomic regions for grain yield, spike productivity components and stripe rust resistance. New candidate genomic regions reflect the potential of Turkish landraces to further increase the genetic diversity in elite germplasm. The crossing program with landraces targets: a) improvement of modern winter wheat germplasm by utilizing drought tolerant and high-yielding landraces and back- or top-crossing F1 to modern varieties; b) improvement of the landraces by incorporation of disease resistance from other landraces or from modern varieties with back- or top-crosses to landraces. Improvement of the landraces and their return to the farming communities is considered an important component of maintaining on-farm genetic diversity.