Mapping Quantitative Trait Loci for Yield Potential Traits in Wheat Recombinant Inbred Lines

Chon-Sik Kang,Kyeong-Min Kim,Chul-Soo Park,Jae-Buhm Chun,Kyeong-Hoon Kim,Young-Jun Mo,Seong-Woo Cho

doi:10.3390/agronomy11010022

Abstract

Selecting wheat with favorable spike characteristics has been a popular breeding strategy to improve sink capacity and yield potential. In the present study, quantitative trait loci (QTLs) for yield potential traits were identified using a recombinant inbred line (RIL) population derived from the cross between Taejoong and Keumkang, two Korean wheat cultivars. A linkage map encompassing a total genetic length of 6544.8 cM was constructed using 838 single nucleotide polymorphisms from the 35K Axiom Wheat Breeder’s Array. We detected eight QTLs for four yield potential traits that are consistently identified in at least two of the three environments, that is, one for days to heading date (QDHD-1 on chromosome 7B), three for spike length (QSL-1, QSL-2, and QSL-3 on chromosomes 1D, 5A, and 6A, respectively), one for tiller number (QTN-1 on chromosome 5B), and three for length of center rachis (QLCR-1, QLCR-2, and QLCR-3 on chromosomes 1B, 5B, and 6A, respectively). Notably, Taejoong contributed the alleles for long spike at all three spike length QTLs with the additive effects of 0.6 cm, 0.6 cm, and 0.9 cm at QSL-1, QSL-2, and QSL-3, respectively. No significant two-way or three-way interaction was observed among QSL-1, QSL-2, and QSL-3, indicating that pyramiding the Taejoong alleles at the three QTLs can increase spike length additively. While the Taejoong alleles at QSL-1, QSL-2, and QSL-3 were associated with increased days to heading date, more kernels per spike, and reduced tiller number per plant, the extent of the pleiotropic effects were different among the three QTLs. Due to the limited number of molecular markers and mapping resolution, further work is required to narrow down the identified QTLs and characterize their effects more precisely. Our results would provide useful information for modulating spike characteristics and improving yield potential in wheat breeding programs.

Highlights

Improving grain yield is an important goal in wheat breeding to secure stable food production under changing climate and increasing world population [1,2]
Studies on wheat yield generally focus on specific yield component traits such as spikes per unit area, kernels per spike, and kernel weight that are more stably inherited than the final grain yield [5,6]
As the genetic factors underlying the large spike characteristics of Taejoong remain unclear, we aimed to identify quantitative trait loci (QTLs) for yield potential characteristics of Taejoong using a recombinant inbred line (RIL) population derived from the cross between

Summary

Introduction

Improving grain yield is an important goal in wheat breeding to secure stable food production under changing climate and increasing world population [1,2]. At the International Maize and Wheat Improvement Center (CIMMYT), large spike wheat cultivars were developed by wide crossing between common wheat and accessions of Agropyron elongatum or Triticum polonicum to improve yield potential through increasing kernels per spike [15]. While these lines showed significant increases in both kernels per spike and kernel weight, the final grain yield fell short of expectations mainly due to the decrease in spikes per unit area [16,17]

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Conclusion