Genome wide identification of QTL associated with yield and yield components in two popular wheat cultivars TAM 111 and TAM 112

Authors: YANG, YAN - Texas A&M Agrilife; DHAKAL, SMIT - Texas A&M Agrilife; Chu, Chenggen; WANG, SHICHEN - Texas A&M Agrilife; XUE, QINGWU - Texas A&M Agrilife; RUDD, JACKIE - Texas A&M Agrilife; IBRAHIM, AMIR - Texas A&M University; JESSUP, KIRK - Texas A&M Agrilife; BAKER, JASON - Texas A&M Agrilife; FUENTEALBA, MARIA - Texas A&M Agrilife

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2020
Publication Date: 12/2/2020
Citation: Yang, Y., Dhakal, S., Chu, C.N., Wang, S., Xue, Q., Rudd, J.C., Ibrahim, A.M., Jessup, K., Baker, J., Fuentealba, M.P. 2020. Genome wide identification of QTL associated with yield and yield components in two popular wheat cultivars TAM 111 and TAM 112. PLoS ONE. 15(12). Article e0237293. https://doi.org/10.1371/journal.pone.0237293.
DOI: https://doi.org/10.1371/journal.pone.0237293

Interpretive Summary: Understanding the genetic control of grain yield and yield-related traits in wheat is of great interest to breeders. In this study, a population of lines developed from the cross between two popular wheat varieties ‘TAM 112’ and ‘TAM 111,’ along with genetic marker information of each line, were used to construct high resolution genetic maps to identify genetic regions associated with yield and yield-related traits in the two varieties. By using data for yield and yield-related traits that were obtained from different environments, several genomic regions were significantly associated with those traits in the two varieties. Comparing effects of each genomic region found genes derived from TAM 112 that mainly increased seed weight and the number of wheat heads per square meter, while genes derived from TAM 111 increased the number of seeds per head and grain yield. The genetic map and markers linked to genomic regions affecting yield and yield-related traits from this study will be very useful in developing high-throughput markers for tracking the desirable traits when using these two popular parental varieties in future wheat improvement efforts.

Technical Abstract: Two drought-tolerant wheat cultivars, ‘TAM 111’ and ‘TAM 112’, have been widely grown in the Southern Great Plains of the U.S. and used as parents in many wheat breeding programs worldwide. This study aimed to reveal genetic control of yield and yield components in the two cultivars under both dryland and irrigated conditions. A mapping population containing 124 F5:7 recombinant inbred lines (RILs) was developed from the cross of TAM 112/TAM 111. A set of 5,948 SNPs from the wheat 90K iSelect array and double digest restriction-site associated DNA sequencing was used to construct high-density genetic maps. Data for yield and yield components were obtained from 11 environments. QTL analyses were performed based on 11 individual environments, across all environments, within and across mega-environments. Thirty-six unique consistent QTL regions were distributed on 13 chromosomes including 1A, 1B, 1D, 2A, 2D, 3D, 4B, 4D, 6A, 6B, 6D, 7B, and 7D. Ten unique QTL with pleiotropic effects were identified on four chromosomes and eight were in common with the consistent QTL. These QTL increased dry biomass grain yield by 16.3 g/m2, plot yield by 28.1 g p/m2, 0.7 kernels per spike, 14.8 spikes/m2, thousand kernel weight by 0.9 g with favorable alleles from either parent. TAM 112 alleles mainly increased spikes/m2 and thousand kernel weight while TAM 111 alleles increased kernels per spike, harvest index and grain yield. The saturated genetic map and markers linked to significant QTL from this study will be very useful in developing high-throughput genotyping markers for tracking the desirable haplotypes of these important yield-related traits in popular parental cultivars.