Genetic architecture of winter hardiness and frost tolerance in triticale.

Wenxin Liu,Guoliang Li,Matthew R Tucker,Tobias Würschum,Elmar A Weissmann,Hans Peter Maurer,Manje Gowda,Volker Hahn,Pilar Hernandez

doi:10.1371/journal.pone.0099848

Abstract

Abiotic stress experienced by autumn-sown crops during winter is of great economic importance as it can have a severe negative impact on yield. In this study, we investigated the genetic architecture of winter hardiness and frost tolerance in triticale. To this end, we used a large mapping population of 647 DH lines phenotyped for both traits in combination with genome-wide marker data. Employing multiple-line cross QTL mapping, we identified nine main effect QTL for winter hardiness and frost tolerance of which six were overlapping between both traits. Three major QTL were identified on chromosomes 5A, 1B and 5R. In addition, an epistasis scan revealed the contribution of epistasis to the genetic architecture of winter hardiness and frost tolerance in triticale. Taken together, our results show that winter hardiness and frost tolerance are complex traits that can be improved by phenotypic selection, but also that genomic approaches hold potential for a knowledge-based improvement of these important traits in elite triticale germplasm.

Highlights

IntroductionIn Central Europe it is commonly planted as winter triticale in autumn, as varieties with a winter growth habit usually have a higher yield potential than varieties planted in spring
Triticale (x Triticosecale Wittmack L.; 2n = 6x = 42) combines properties of its two parents, wheat and rye, and is primarily grown in the northern hemisphere
The mapping population consisted of 647 doubled haploid (DH) [23,24] triticale (x Triticosecale Wittmack L.) lines derived from four families, DH06 (131), DH07 (120), EAW74 (200), and EAW78 (196) that have been described by Alheit et al [25,26]

Summary

Introduction

In Central Europe it is commonly planted as winter triticale in autumn, as varieties with a winter growth habit usually have a higher yield potential than varieties planted in spring. A prerequisite for these winter-type varieties is that they possess an adequate tolerance to endure the harsh conditions during winter in temperate zones. The capability of these plants to survive winter can be referred to as winter hardiness, involving among other factors freezing tolerance, desiccation, anoxia and disease resistance [1]. Progress by breeders to improve these traits has been slow, which is further aggravated by the variable occurrence of this type of stress across years

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