AUTHOR=Hatzig Sarah V. , Frisch Matthias , Breuer Frank , Nesi Nathalie , Ducournau Sylvie , Wagner Marie-Helene , Leckband Gunhild , Abbadi Amine , Snowdon Rod J. 

TITLE=Genome-wide association mapping unravels the genetic control of seed germination and vigor in Brassica napus

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00221

DOI=10.3389/fpls.2015.00221

ISSN=1664-462X

ABSTRACT=<p>Rapid and uniform seed germination is a crucial prerequisite for crop establishment and high yield levels in crop production. A disclosure of genetic factors contributing to adequate seed vigor would help to further increase yield potential and stability. Here we carried out a genome-wide association study in order to define genomic regions influencing seed germination and early seedling growth in oilseed rape (<italic>Brassica napus</italic> L.). A population of 248 genetically diverse winter-type <italic>B</italic>. <italic>napus</italic> accessions was genotyped with the <italic>Brassica</italic> 60k SNP Illumina genotyping array. Automated high-throughput <italic>in vitro</italic> phenotyping provided extensive data for multiple traits related to germination and early vigor, such as germination speed, absolute germination rate and radicle elongation. The data obtained indicate that seed germination and radicle growth are strongly environmentally dependent, but could nevertheless be substantially improved by genomic-based breeding. Conditions during seed production and storage were shown to have a profound effect on seed vigor, and a variable manifestation of seed dormancy appears to contribute to differences in germination performance in <italic>B. napus</italic>. Several promising positional and functional candidate genes could be identified within the genomic regions associated with germination speed, absolute germination rate, radicle growth and thousand seed weight. These include <italic>B. napus</italic> orthologs of the <italic>Arabidopsis thaliana</italic> genes <italic>SNOWY COTYLEDON 1</italic> (<italic>SCO1</italic>), <italic>ARABIDOPSIS TWO-COMPONENT RESPONSE REGULATOR</italic> (<italic>ARR4</italic>), and <italic>ARGINYL-t-RNA PROTEIN TRANSFERASE 1</italic> (<italic>ATE1</italic>), which have been shown previously to play a role in seed germination and seedling growth in <italic>A. thaliana</italic>.</p>