Identification of Quantitative Trait Loci Controlling Agronomic Traits Indicates Breeding Potential of Tibetan Semiwild Wheat (Triticum aestivum ssp. tibetanum)

Abstract

Tibetan semiwild wheat (Triticum aestivum ssp. tibetanum Shao) is a primitive hexaploid wheat resource found in Tibet. It is characterized by tolerance to nutrition deficiency and strong seed dormancy and has potential to be useful in wheat breeding programs. To tap the advantages of Tibetan semiwild wheat in wheat breeding, we investigated nine agronomic traits including heading date (HD), anthesis date (AD), plant height (PHT), tiller number (TN), spike length (SL), spikelet number per spike (SNS), spikelet density (DS), grain weight per spike (GWS), and 1000‐grain weight (TGW) in 186 recombinant inbred lines from a cross between Tibetan semiwild wheat ‘Q1028’ and common wheat ‘Zhengmai 9023’ (ZM 9023) across three growing seasons. Forty‐five qualitative trait loci (QTLs) on 12 chromosomes were detected. The phenotypic variation explained by each of these QTL ranged from 4.7 to 29.7%. Positive alleles for 28 of these QTLs were derived from Q1028. Of these QTLs, 25 (56%) were detected in at least two growing seasons. Fifteen stable QTLs that were significant across all three growing seasons were identified. Novel QTLs derived from Q1028 were identified, such as QSd.sau‐7A for spikelet density, QTgw.sau‐2B for TGW and QSns.sau‐3D for SNS. Eleven QTL clusters were detected, including one on chromosome 5A flanked by the markers wPt‐9094 and wPt‐9513. This cluster consists of QTLs controlling HD, AN, PHT, SL, and spikelet density and explained 6.6 to 12.6% of the phenotypic variation in these traits. The QTLs and molecular markers identified here could be useful in fine mapping and breeding programs.

Several stably expressed QTL for spike density of common wheat (Triticum aestivum) in multiple environments

“…QSd.sicau‐2D.3 was located between 602.18 Mbp and 606.92 Mbp on chromosome 2Dl of Chinese Spring. Previously, Liu et al (), Gao et al () and Luo et al () reported several SD QTL, physically located between 645.36 and 649.86 Mbp, 637.63 and 637.65 Mbp, 635.95 and 637.63 Mbp, and 585.68 Mbp and 609.88 Mbp, respectively (Table S2), indicating QSd.sicau‐2D.3 was close to these intervals. Thus, QSd.sicau‐2D.3 is likely an allele variant of these QTLs.…”

“…This is not uncommon in numerous studies on QTL identification based on crossing populations. For example, quite a few of previous studies have also identified SD QTL in crossing populations where no significant differences were detected between their parents (Luo et al, ; Zhou et al, ).…”

“…Recently, numerous SD QTL of wheat has been identified on almost 21 wheat chromosomes (Faris, Zhang, Chao, Zhang, & Xu, ; Li et al, ; Luo et al, ; Marza, B. G‐H, B.F. Carver, & Z.…”

Genome-wide association study reveals new loci for yield-related traits in Sichuan wheat germplasm under stripe rust stress

“…Markers associated to yield-related traits [58], and the QSL.sicau-4AS was covered by QSl.sau-4A [59]. Two QTLs were located at 5AL.…”

Genome-wide association study reveals new loci for yield-related traits in Sichuan wheat germplasm under stripe rust stress

“…QSL.sicau-2AL was located around the position of 432.58 Mb at 2A, which was the same as QSl.sdau-2A[57]. QSL.sicau-2DS overlapped with QPht/SL.cau-2D.2[58], and the QSL.sicau-4AS was covered by QSl.sau-4A[59]. Two QTLs were located at 5AL.…”