QTL for horticulturally important traits associated with pleiotropic andromonoecy and carpel number loci, and a paracentric inversion in cucumber
QTL for horticulturally important traits associated with pleiotropic andromonoecy and carpel number loci, and a paracentric inversion in cucumber
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与多效性雄性同花性和心皮数位点相关的园艺重要性状 QTL，以及黄瓜的旁心倒位
DOI：
10.1007/s00122-020-03596-y
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发表时间：
2020-04-18
影响因子：
5.4
通讯作者：
Weng, Yiqun
中科院分区：
文献类型：
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作者：
Pan, Yupeng;Wen, Changlong;Weng, Yiqun
传说中的黄瓜自交系WI2757具有罕见的对9种病原体的抗性组合，是黄瓜育种的重要种质。然而，WI2757开花较晚，在田间条件下表现不佳。 WI2757 中除抗病性之外的园艺重要性状的遗传基础在很大程度上尚不清楚。在这项研究中，我们使用来自 WI2757 x True Lemon 杂交的 F-2 和重组自交系 (RIL) 群体进行了 QTL 作图，这些群体分离了多个性状。通过多年的重复田间试验收集了包括果实心皮数量（CN）和性别表达在内的七个性状的表型数据。通过对 RIL 群体进行测序进行基因分型，开发了基于高密度 SNP 的遗传图谱，该图谱揭示了 1 号染色体上具有强烈重组抑制的区域。该区域重组减少是由于 WI2757 中出现类似于 10-Mbp 的同心倒位，这一点已通过额外的分离和细胞学 (FISH) 分析得到证实。检测了36个开花时间、果长(FL)、果径(FD)、果形(LD)、果数(FN)、CN和白粉病抗性QTL。倒位内的 FL、FD、LD 和 FN 的五个中效或重效 QTL 可能是雄雌同株 (m) 或 cn 基因座的多效性效应。主效开花时间QTL ft1.1也被映射到反演内部，这似乎与之前指定的WI2757延迟开花不同。讨论了这些发现对 WI2757 在黄瓜育种中的应用的影响。
The legendary cucumber inbred line WI2757 possesses a rare combination of resistances against nine pathogens, which is an important germplasm for cucumber breeding. However, WI2757 flowers late and does not perform well under field conditions. The genetic basis for horticulturally important traits other than disease resistances in WI2757 is largely unknown. In this study, we conducted QTL mapping using F-2 and recombinant inbred line (RIL) populations from the WI2757 x True Lemon cross that were segregating for multiple traits. Phenotypic data were collected in replicated field trials across multiple years for seven traits including fruit carpel number (CN) and sex expression. A high-density SNP-based genetic map was developed with genotyping by sequencing of the RIL population, which revealed a region on chromosome 1 with strong recombination suppression. The reduced recombination in this region was due to a similar to 10-Mbp paracentric inversion in WI2757 that was confirmed with additional segregation and cytological (FISH) analyses. Thirty-six QTL were detected for flowering time, fruit length (FL), fruit diameter (FD), fruit shape (LD), fruit number (FN), CN, and powdery mildew resistance. Five moderate- or major-effect QTL for FL, FD, LD, and FN inside the inversion are likely the pleiotropic effects of the andromonoecy (m), or the cn locus. The major-effect flowering time QTL ft1.1 was also mapped inside the inversion, which seems to be different from the previously assigned delayed flowering in WI2757. Implications of these findings on the use of WI2757 in cucumber breeding are discussed.