Fine mapping qGL2H, a major locus controlling grain length in barley (Hordeum vulgare L.)

Calum Watt, Gaofeng Zhou, Lee-Anne McFawn & Chengdao Li

Theoretical and Applied Genetics – July 2020; vol. 133:2095–2103

Key message

A major grain length QTL on chromosome 2H was fine mapped to a 140.9 Kb region containing three genes.

Abstract

Increasing yield is an important target for barley breeding programs. One approach to increase yield is by enhancing individual grain weights through the regulation of grain size. Fine mapping major grain size-related quantitative trait loci is necessary for future marker-assisted selection strategies, yet studies of this nature are limited in barley. In the present study, we utilised a doubled haploid population derived from two Australian malt barley varieties, Vlamingh and Buloke, coupled with extensive genotypic and phenotypic data from three independent environments. A major grain length locus identified on chromosome 2H designated qGL2H was fine mapped to a 140.9 Kb interval. qGL2H was able to account for 25.4% of the phenotypic variation for grain length and 10.2% for grain yield. Underlying qGL2H were three high-confidence predicted genes. One of these genes encodes a MYB transcription factor and represents a promising candidate for further genetic research.

See https://link.springer.com/article/10.1007/s00122-020-03579-z

Figure 2: Fine mapping result of qGL2H. a Subset of whole-genome marker data and consensus QTL interval (red) detected during initial whole-genome mapping and b genetic map created using InDel markers (Table S1) and associated fine-mapped QTL region (black)