Genetic mapping of local adaptation along the altitudinal gradient in Abies sachalinensis
Genetic mapping of local adaptation along the altitudinal gradient in Abies sachalinensis
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DOI：
10.1007/s11295-017-1191-3
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发表时间：
2017-10-01
影响因子：
2.4
通讯作者：
Iwata, Hiroyoshi
中科院分区：
文献类型：
--
作者：
Goto, Susumu;Kajiya-Kanegae, Hiromi;Iwata, Hiroyoshi
了解主要针叶树种当地适应的遗传基础对于预测快速气候变化对森林生态系统的影响至关重要。然而，适应的遗传基础尚未完全理解，由于庞大而复杂的基因组的针叶树和不可用的日期合适的杂交材料。本研究构建了高山冷杉（Abies sachalinensis，2n = 24）的遗传连锁图，并沿海拔梯度沿着定位了与高山冷杉局部适应性相关的数量性状基因座（QTL）。从两个F-1杂种（高海拔×低海拔基因型）之间的杂交产生239个幼苗的分离群体。采用伪测交策略，利用基于1251个单核苷酸多态性（SNP）和3个简单序列重复（SSR）标记的连锁图谱，对物候和生长性状进行了QTL定位。两张图谱由12个连锁群组成，平均标记间距约为1.5。为每个亲本构建3cM。地图的总长度为1861和1949厘米。排列检验鉴定出4个显著性QTL和11个额外的提示性QTL，具有高比值对数（LOD）得分（> 3.0）。这是第一个高度饱和的连锁图谱冷杉类群。结果表明，春芽物候期受多个中等效应的QTL控制。通过杂交两个杂交种（高×低海拔基因型）和许多SNP标记创建的作图群体的使用使我们能够调查针叶树种适应性性状的遗传基础。
Understanding the genetic bases of local adaptation in dominant conifer species is critical in predicting the impacts of rapid climate change on forest ecosystems. However, the genetic basis of adaptation is not yet fully understood due to the huge and complex genomes of conifers and the unavailability to date of suitable crossing material. In this study, we constructed a linkage map for Abies sachalinensis (2n = 24) and investigated quantitative trait loci (QTLs) associated with local adaptation along an altitudinal gradient. A segregating population of 239 seedlings was produced from a cross between two F-1 hybrids (high-altitude x low-altitude genotypes). QTL mapping of phenological and growth traits was performed using a pseudo-testcross strategy with linkage maps based on 1251 single-nucleotide polymorphism (SNP) and three simple sequence repeat (SSR) markers. Two maps consisting of 12 linkage groups with an average marker interval of ca. 3 cM were constructed for each parent. The total lengths of the maps were 1861 and 1949 cM. A permutation test identified four significant QTLs and 11 additional suggestive QTLs, with high logarithm of odds (LOD) scores (> 3.0). This is the first highly saturated linkage map produced for Abies taxa. Our results suggest that spring bud phenology is controlled by several QTLs with moderate effects. The use of the mapping population created by crossing two hybrids (high x low altitude genotypes) and numerous SNP markers enabled us to investigate the genetic basis of adaptive traits in conifer species.