AUTHOR=Zhang Guofang , Zhou Jinzhi , Peng Yan , Tan Zengdong , Li Long , Yu Liangqian , Jin Cheng , Fang Shuai , Lu Shaoping , Guo Liang , Yao Xuan 

TITLE=Genome-Wide Association Studies of Salt Tolerance at Seed Germination and Seedling Stages in Brassica napus

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.772708

DOI=10.3389/fpls.2021.772708

ISSN=1664-462X

ABSTRACT=<p>Most crops are sensitive to salt stress, but their degree of susceptibility varies among species and cultivars. In order to understand the salt stress adaptability of <italic>Brassica napus</italic> to salt stress, we collected the phenotypic data of 505 <italic>B. napus</italic> accessions at the germination stage under 150 or 215 mM sodium chloride (NaCl) and at the seedling stage under 215 mM NaCl. Genome-wide association studies (GWAS) of 16 salt tolerance coefficients (STCs) were applied to investigate the genetic basis of salt stress tolerance of <italic>B. napus</italic>. In this study, we mapped 31 salts stress-related QTLs and identified 177 and 228 candidate genes related to salt stress tolerance were detected at germination and seedling stages, respectively. Overexpression of two candidate genes, <italic>BnCKX5</italic> and <italic>BnERF3</italic> overexpression, were found to increase the sensitivity to salt and mannitol stresses at the germination stage. This study demonstrated that it is a feasible method to dissect the genetic basis of salt stress tolerance at germination and seedling stages in <italic>B. napus</italic> by GWAS, which provides valuable loci for improving the salt stress tolerance of <italic>B. napus</italic>. Moreover, these candidate genes are rich genetic resources for the following exploration of molecular mechanisms in adaptation to salt stress in <italic>B. napus</italic>.</p>