A 55K SNP array-based genetic map and its utilization in QTL mapping for productive tiller number in common wheat

摘要

Key messageA high-density genetic map constructed with a wheat 55K SNP array was highly consistent with the physical map of this species and it facilitated the identification of a novel major QTL for productive tiller number.AbstractProductive tiller number (PTN) plays a key role in wheat grain yield. In this study, a recombinant inbred line population with 199 lines derived from a cross between 20828' and Chuannong16' was used to construct a high-density genetic map using wheat 55K single nucleotide polymorphism (SNP) array. The constructed genetic map contains 12,109 SNP markers spanning 3021.04cM across the 21 wheat chromosomes. The orders of the genetic and physical positions of these markers are generally in agreement, and they also match well with those based on the 660K SNP array from which the one used in this study was derived. The ratios of SNPs located in each of the wheat deletion bins were similar among the wheat 9K, 55K, 90K, 660K and 820K SNP arrays. Based on the constructed maps, a novel major quantitative trait locus QPtn.sau-4B for PTN was detected across multi-environments in a 0.55cM interval on 4B and it explained 17.23-45.46% of the phenotypic variance. Twenty common genes in the physical interval between the flanking markers were identified on chromosome 4B of Chinese Spring' and wild emmer. These results indicate that wheat 55K SNP array could be an ideal tool in primary mapping of target genes and the identification of QPtn.sau-4B laid a foundation for the following fine mapping and cloning work.