Genetic Mapping and Candidate Gene Prediction of a QTL Related to Early Heading on Wild Emmer Chromosome 7BS in the Genetic Background of Common Wheat
Genetic Mapping and Candidate Gene Prediction of a QTL Related to Early Heading on Wild Emmer Chromosome 7BS in the Genetic Background of Common Wheat
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DOI：
10.3390/agronomy12051089
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发表时间：
2022-04
期刊：
影响因子：
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通讯作者：
Fei Lu;Man-yuan Chen;Yanhao Zhao;Shaoxin Wu;Muhammad Yasir;Hua Zhang;Xinseng Hu;J. Rong
中科院分区：
文献类型：
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作者：
Fei Lu;Man-yuan Chen;Yanhao Zhao;Shaoxin Wu;Muhammad Yasir;Hua Zhang;Xinseng Hu;J. Rong
抽穗期是小麦常规育种的重要农艺指标。多年田间试验结果表明，野生二粒小麦7 BS染色体臂代换系（CASL）是在普通小麦变异系（V.A.）的遗传背景下获得的。中国春（CS）总是表现出显着早于CS种植在不同的季节HD，通常约8天比CS下正常秋播季节。CASL 7 BS一致地显示出早得多的HD比CS处理春化下长或短的光周期，然后生长在生长室中的短或长的光周期。在长日照条件下，CASL 7 BS在颖壳期前的穗发育速度快于CS，而在短日照条件下，各生育期的穗发育速度均相对较快。为了定位CASL 7 BS中的早期基因，将来自CASL 7 BS和CS的杂交F2植株种植在田间和生长室中，形成两个定位群体（分别为P1和P2）。根据P1的HD分布，HD很可能受显性基因调控。在C268和C309两侧8.94cM的远缘区域检测到一个QTL，LOD值为5-8，分别解释了9.14%和12.35%的表型变异。根据F3和F4家系的HD和基因型进一步将QTL缩小到ZAFU 058724和ZAFU 061354之间58-61 Mb的区间。在该区域共定位了41个基因，根据基因功能，其中11个基因被认为是候选基因。根据HD和定位结果，本研究所鉴定的QTL是一个新的开花相关基因，这将有助于理解小麦开花的机理，并为早熟小麦品种的选育提供理论依据。
Heading date (HD) is an essential agronomic objective in wheat conventional breeding. Field experiments from several years and locations indicated that the chromosome arm substitution line (CASL) of wild emmer chromosome 7BS in the genetic background of common wheat var. Chinese Spring (CS) always showed a substantially earlier HD than CS planted in different seasons; usually about 8 d earlier than CS grown under a normal autumn sowing season. CASL7BS consistently showed a much earlier HD than CS when treated for vernalization under a long or short photoperiod and then grown under a short or long photoperiod in the growth room. CASL7BS showed faster spike development than CS at the stages before the glume stage when grown under long days, and depicted relatively rapid growth at all stages when grown under short days. To map the early gene in CASL7BS, F2 plants from the cross of CASL7BS and CS were planted in the field and growth room, forming two mapping populations (P1 and P2, respectively). According to the HD distribution of P1, the HD was most likely regulated by a dominant gene. A QTL was detected consistently in the distal region of about 8.94 cM flanked by C268 and C309 with LOD scores of 5–8, explaining 9.14 and 12.35% of the phenotypic variation in the two mapping populations. The QTL was further narrowed down to an interval between ZAFU058724 and ZAFU061354 of 58–61 Mb based on the HD and genotype of F3 and F4 families. A total of 41 genes were located in this region, and eleven of them were thought to be the candidate genes based on the gene functions. According to the HD and mapping location, the QTL identified in this study was a new gene associated with flowering, which will be helpful in understanding the mechanism of wheat flowering and for breeding an early wheat variety.