Genome-Wide Linkage Mapping Reveals QTLs for Seed Vigor-Related Traits Under Artificial Aging in Common Wheat (Triticum aestivum)

Abstract

Long-term storage of seeds leads to lose seed vigor with slow and non-uniform germination. Time, rate, homogeneity, and synchrony are important aspects during the dynamic germination process to assess seed viability after storage. The aim of this study is to identify quantitative trait loci (QTLs) using a high-density genetic linkage map of common wheat (Triticum aestivum) for seed vigor-related traits under artificial aging. Two hundred and forty-six recombinant inbred lines derived from the cross between Zhou 8425B and Chinese Spring were evaluated for seed storability. Ninety-six QTLs were detected on all wheat chromosomes except 2B, 4D, 6D, and 7D, explaining 2.9–19.4% of the phenotypic variance. These QTLs were clustered into 17 QTL-rich regions on chromosomes 1AL, 2DS, 3AS (3), 3BS, 3BL (2), 3DL, 4AS, 4AL (3), 5AS, 5DS, 6BL, and 7AL, exhibiting pleiotropic effects. Moreover, 10 stable QTLs were identified on chromosomes 2D, 3D, 4A, and 6B (QaMGT.cas-2DS.2, QaMGR.cas-2DS.2, QaFCGR.cas-2DS.2, QaGI.cas-3DL, QaGR.cas-3DL, QaFCGR.cas-3DL, QaMGT.cas-4AS, QaMGR.cas-4AS, QaZ.cas-4AS, and QaGR.cas-6BL.2). Our results indicate that one of the stable QTL-rich regions on chromosome 2D flanked by IWB21991 and IWB11197 in the position from 46 to 51 cM, presenting as a pleiotropic locus strongly impacting seed vigor-related traits under artificial aging. These new QTLs and tightly linked SNP markers may provide new valuable information and could serve as targets for fine mapping or markers assisted breeding.

Genome‐wide association study reveals loci associated with seed longevity in common wheat (Triticum aestivum L.)

“…Rehman Arif et al () found five DArT markers significantly associated with seed longevity on chromosomes 3A ( wPt‐6854 , wPt‐6854 , wPt‐7340 ), 3B ( wPt‐5105 ) and 6A ( wPt‐3605 ), which were overlapped or close to the loci identified in our study on chromosomes 3A ( QlgGR.cas‐3A.1 , QlgGR.cas‐3A.2 , QlgGR.cas‐3A.3 ), 3B ( QlgGR.cas‐3B ) and 6A ( QlgGR.cas‐6A.1 ) based on the 90K consensus map (Wang et al, ) and the integrated map (Maccaferri et al, ). Zuo et al () identified four loci ( QaGR.cas‐2Dl , QaGR.cas‐3A.1 , QaGR.cas‐4Al.3 and QaGR.cas‐6AS ) controlling seed longevity‐related traits in a 'Chinese Spring'/Zhou 8425B RIL population, which were consistent with the loci identified in this study on chromosomes 2D ( QlgGR.cas‐2D ), 3A ( QlgGR.cas‐3A.1 ), 4A ( QlgGR.cas‐4A.1 ) and 6A ( QlgGR.cas‐6A.1 ). Besides, QlgGR.cas‐2B.2 , QlgGR.cas‐2B.1 , QlgGR.cas‐2B.2 and QlgGR.cas‐5D were close to QLng.ipk‐2B (Agacka‐Moldoch et al, ), QLng.ipk‐2B (Agacka‐Moldoch et al, ) and QAa‐fingp.ipk‐5D (Landjeva et al, ).…”

“…The key to improve seed longevity in common wheat was uncovering deterioration mechanisms and identifying longevity‐related loci. However, most of the previous studies for seed longevity focused on storage conditions, and very few works have been cited regarding molecular mechanisms in common wheat (Wu et al, ; Zuo et al, ). In this study, 166 wheat accessions were evaluated for seed longevity‐related trait.…”

“…Fifty wheat seeds each line of uniform size were equilibrated at room temperature in the container, and after 4‐day equilibration, seeds were artificially aged. The CDT treatment was conducted at 44.5 ± 0.1 ℃ temperature and 82% relative humidity for 2 days (Zuo et al, ). Then, the artificially aged seeds were dried at room temperature for 1 day and then used for the germination test.…”

“…Then, the artificially aged seeds were dried at room temperature for 1 day and then used for the germination test. Fifty wheat seeds each line with three replications were placed in Petri dishes on moist filter papers at 23 ℃ under a 18/6 (day/night) photoperiod (Landjeva, Lohwasser, & Börner, ; Zuo et al, ). The seed was scored as germinated when the radicle length surpassed its grain length.…”

“…Studies of seed longevity under conventional storage conditions would take years to complete. Controlled deterioration tests (CDT) with seeds exposed to high relative humidity and temperature have been developed to quickly assess seed longevity in Arabidopsis , rice, lettuce, maize, barley and wheat (Bentsink et al, ; Jiang et al, ; Nguyen et al, ; Rajjou & Debeaujon, ; Zuo et al, ).…”