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Abstract：
In arid and semi-arid regions, coleoptile length is a vital agronomic trait for wheat breeding. The coleoptile length determines the maximum depth that seeds can be sown, and it is critical for establishment of the crop. Therefore, identifying loci associated with coleoptile length in wheat is essential. In the present study, 282 accessions from Shanxi Province representing wheat breeding for the Loess Plateau were grown under three experimental conditions to study coleoptile length. The results of phenotypic variation indicated that drought stress and light stress could lead to shortening of coleoptile length. Under drought stress the growth rate of environmentally sensitive cultivars decreased more than insensitive cultivars. The broad-sense heritability (H 2) of BLUP (best linear unbiased prediction) under various conditions showed G × E interaction for coleoptile length but was mainly influenced by heredity. Correlation analysis showed that correlation between plant height-related traits and coleoptile length was significant in modern cultivars whereas it was not significant in landraces. A total of 45 significant marker-trait associations (MTAs) for coleoptile length in the three conditions were identified using the 3VmrMLM (3 Variance-component multi-locus random-SNP-effect Mixed Linear Model) and MLM (mixed linear model). In total, nine stable genetic loci were identified via 3VmrMLM under the three conditions, explaining 2.94-7.79% of phenotypic variation. Five loci on chromosome 2B, 3A, 3B, and 5B have not been reported previously. Six loci had additive effects toward increasing coleoptile length, three of which are novel. Molecular markers for the loci with additive effects on coleoptile length can be used to breed cultivars with long coleoptiles.
摘要：
在干旱和半干旱地区，胚芽鞘长度是小麦育种的重要农艺性状。胚芽鞘的长度决定了种子可以播种的最大深度，这对作物的建立至关重要。因此,确定与小麦胚芽鞘长度相关的基因座是必不可少的。在本研究中,在三个实验条件下种植了282份代表黄土高原小麦育种的山西省种质，以研究胚芽鞘长度。表型变异结果表明，干旱胁迫和光照胁迫均可导致胚芽鞘长度缩短。在干旱胁迫下，环境敏感品种的生长速率比不敏感品种的生长速率下降更多。BLUP（最佳线性无偏预测）在各种条件下的广义遗传力（H2）显示胚芽鞘长度的G×E相互作用，但主要受遗传影响。相关分析表明，在现代品种中，株高相关性状与胚芽鞘长度之间的相关性显着，而在地方品种中不显著。使用3VmrMLM（3个方差分量多位点随机SNP效应混合线性模型）和MLM（混合线性模型）鉴定了三种条件下胚芽鞘长度的共45个显着的标记-性状关联（MTA）。总的来说,在三种条件下通过3VmrMLM鉴定出9个稳定的遗传位点，解释2.94-7.79%的表型变异。2B染色体上的五个基因座，3A,3B,和5B以前没有报道。六个基因座对增加胚芽鞘长度具有加性作用，其中三个是小说。对胚芽鞘长度具有加性作用的基因座的分子标记可用于选育具有长胚芽鞘的品种。
