First insights into the genotype–phenotype map of phenotypic stability in rye

Yu Wang,Peer Wilde,Thomas Miedaner,Yusheng Zhao,Jochen C. Reif,Michael Florian Mette

doi:10.1093/jxb/erv145

Abstract

Improving phenotypic stability of crops is pivotal for coping with the detrimental impacts of climate change. The goal of this study was to gain first insights into the genetic architecture of phenotypic stability in cereals. To this end, we determined grain yield, thousand kernel weight, test weight, falling number, and both protein and soluble pentosan content for two large bi-parental rye populations connected through one common parent and grown in multi-environmental field trials involving more than 15 000 yield plots. Based on these extensive phenotypic data, we calculated parameters for static and dynamic phenotypic stability of the different traits and applied linkage mapping using whole-genome molecular marker profiles. While we observed an absence of large-effect quantitative trait loci (QTLs) underlying yield stability, large and stable QTLs were found for phenotypic stability of test weight, soluble pentosan content, and falling number. Applying genome-wide selection, which in contrast to marker-assisted selection also takes into account loci with small-effect sizes, considerably increased the accuracy of prediction of phenotypic stability for all traits by exploiting both genetic relatedness and linkage between single-nucleotide polymorphisms and QTLs. We conclude that breeding for crop phenotypic stability can be improved in related populations using genomic selection approaches established upon extensive phenotypic data.

Highlights

The primary goal in plant breeding is to identify high-yielding genotypes combining excellent quality with pronounced resistance to abiotic and biotic stresses
We determined grain yield, thousand kernel weight, test weight, falling number, and both protein and soluble pentosan content for two large bi-parental rye populations connected through one common parent and grown in multi-environmental field trials involving more than 15 000 yield plots
While we observed an absence of large-effect quantitative trait loci (QTLs) underlying yield stability, large and stable QTLs were found for phenotypic stability of test weight, soluble pentosan content, and falling number

Summary

Introduction

The primary goal in plant breeding is to identify high-yielding genotypes combining excellent quality with pronounced resistance to abiotic and biotic stresses. Stability can be defined either as static or dynamic phenotypic stability (Becker and Léon, 1988). Static phenotypic stability refers to the ability of a genotype to realize a constant performance independent of the variation of environmental conditions. For traits such as grain yield, is often associated with relatively low performance (Lin et al, 1986; Becker and Léon, 1988). In this case, dynamic phenotypic stability concepts describing the ability of a genotype to respond to improved agronomic conditions of an environment with increased performance are considered to be more relevant. Dynamic stability can be estimated by Shukla’s (1972) stability variance, or by Wricke’s (1962) ecovalence, which provide a measure of genotype stability based on estimates of genotype and environment interaction variance corresponding to an individual genotype

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