Extreme QTL mapping of germination speed in Arabidopsis thaliana

Wei Yuan, Jonathan M. Flowers, Dustin J. Sahraie, Ian M. Ehrenreich, Michael D. Purugganan

Research output: Contribution to journalArticle

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.

Original languageEnglish (US)
Pages (from-to)4177-4196
Number of pages20
JournalMolecular ecology
Volume25
Issue number17
DOIs
StatePublished - Sep 1 2016

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Keywords

  • bulk-segregant analysis
  • life history
  • quantitative genomics
  • seed ecology

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics

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