Abstract
High-density genetic linkage maps of crop species are particularly useful in detecting qualitative and quantitative trait loci for important agronomic traits and in improving the power of classical approaches to identify candidate genes. The aim of this study was to develop a high-density genetic linkage map in a durum wheat recombinant inbred lines population (RIL) derived from two elite wheat cultivars and to identify, characterize and correlate Quantitative Trait Loci (QTL) for β-glucan, protein content, grain yield per spike and heading time. A dense map constructed by genotyping the RIL population with the wheat 90K iSelect array included 5444 single nucleotide polymorphism (SNP) markers distributed in 36 linkage groups. Data for β-glucan and protein content, grain yield per spike and heading time were obtained from replicated trials conducted at two locations in southern Italy. A total of 19 QTL were detected in different chromosome regions. In particular, three QTL for β-glucan content were detected on chromosomes 2A and 2B (two loci); eight QTL controlling grain protein content were detected on chromosomes 1B, 2B, 3B (two loci), 4A, 5A, 7A and 7B; seven QTL for grain yield per spike were identified on chromosomes 1A, 2B, 3A (two loci), 3B (two loci) and 6B; and one marker-trait association was detected on chromosome 2A for heading time. The last was co-located with a β-glucan QTL, and the two QTL appeared to be negatively correlated. A genome scan for genomic regions controlling the traits and SNP annotated sequences identified five putative candidate genes involved in different biosynthesis pathways (β-glucosidase, GLU1a; APETALA2, TaAP2; gigantea 3, TaGI3; 14-3-3 protein, Ta14A; and photoperiod sensitivity, Ppd-A1). This study provides additional information on QTL for important agronomic traits that could be useful for marker-assisted breeding to obtain new genotypes with commercial and nutritional relevance.
Highlights
Our objectives were to: (a) evaluate the genetic variation in β-glucan and protein content, grain yield per spike and heading time in a recombinant inbred line (RIL) population derived from a cross between two elite durum wheat cultivars; (b) develop a high-density single nucleotide polymorphism (SNP)-based genetic linkage map; (c) identify and characterise Quantitative Trait Loci (QTL) for β-glucans and protein content, grain yield per spike and heading time; and (d) identify candidate genes associated with the analysed traits
The parental lines and recombinant inbred lines population (RIL) were evaluated for β-glucan (BG), grain protein content (GPC), grain yield per spike (GYS), and heading time (HT) in replicated trials at Policoro and Valenzano in southern Italy in 2014
We report a high-density SNP-based genetic map for the Duilio × Avonlea durum wheat RIL population
Summary
Durum) is the tenth most widely grown crop on the planet with production of more than 36 million metric tons It is commonly cultivated on both south and north shores of the Mediterranean Sea, with the largest proportion of the global production focused there. High protein content brings high water absorbance and increases the shelf life of the products Another important technological parameter is fibre content, which is linked with many health benefits including those associated with immunomodulatory activity, blood cholesterol, faecal bulking effects, mineral absorption, prebiotic effects, and reduced type II diabetes [4]. Mohamed et al [6] reported a delay in the hardening of bread containing β-glucan during storage, whereas Kurek et al [7] found a positive effect of β-glucan on product quality due to increased water retention in the bread They have potential use as functional ingredients to improve mouth-feel of low-fat dairy products [4].
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