Extreme QTL mapping of germination speed in m>Arabidopsis thalianam>

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• 作者：Wei Yuan ; Jonathan M. Flowers ; Dustin J. Sahraie ; Ian M. Ehrenreich and Michael D. Purugganan
• 刊名：Molecular Ecology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：25
• 期：17
• 页码：4177-4196
• 全文大小：1413K
• ISSN：1365-294X

文摘

Seed germination is a key life history transition for annual plants and partly determines lifetime performance and fitness. Germination speed, the elapsed time for a nondormant seed to germinate, is a poorly understood trait important for plants’ competitiveness and fitness in fluctuating environments. Germination speed varied by 30% among 18 m>Arabidopsis thalianam> populations measured, and exhibited weak negative correlation with flowering time and seed weight, with significant genotype effect (m>Pm> < 0.005). To dissect the genetic architecture of germination speed, we developed the extreme QTL (X-QTL) mapping method in m>A. thalianam>. The method has been shown in yeast to increase QTL mapping power by integrating selective screening and bulk-segregant analysis in a very large mapping population. By pooled genotyping of top 5% of rapid germinants from ~100 000 F₃ individuals, three X-QTL regions were identified on chromosomes 1, 3 and 4. All regions were confirmed as QTL regions by sequencing 192 rapid germinants from an independent F₃ selection experiment. Positional overlaps were found between X-QTLs and previously identified seed, life history and fitness QTLs. Our method provides a rapid mapping platform in m>A. thalianam> with potentially greater power. One can also relate identified X-QTLs to the m>A. thalianam> physical map, facilitating candidate gene identification.