Extreme QTL mapping of germination speed in Arabidopsis thaliana. Issue 17 (September 2016)

• Record Type: Journal Article
• Authors: Yuan, Wei; Flowers, Jonathan M.; Sahraie, Dustin J.; Ehrenreich, Ian M.; Purugganan, Michael D.
• Is Part Of: Molecular ecology. Volume 25:Issue 17(2016)
• Page Start: 4177
• Page End: 4196
• Publication Date: 2016-09
• Subjects: bulk‐segregant analysis -- life history -- quantitative genomics -- seed ecology; Molecular ecology -- Periodicals; Molecular population biology -- Periodicals; 576
• DOI: 10.1111/mec.13768
• Languages: English
• ISSNs: 0962-1083

Abstract

Abstract: 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 Arabidopsis thaliana populations measured, and exhibited weak negative correlation with flowering time and seed weight, with significant genotype effect ( P < 0.005). To dissect the genetic architecture of germination speed, we developed the extreme QTL (X‐QTL) mapping method in A. thaliana . 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 A. thaliana with potentially greater power. One can also relate identified X‐QTLs to the A. thaliana physical map, facilitating candidate gene identification.