Genome-wide association studies in the genetic dissection of ovule number, seed number, and seed weight in Brassica napus L
2019
Khan, Shahid Ullah | Yangmiao, Jiao | Liu, Sheng | Zhang, Kunpeng | Khan, Muhammad Hafeez Ullah | Zhai, Yungu | Olalekan, Amoo | Fan, Chuchuan | Zhou, Yongming
Ovule number (ON), seed per silique (SS), and thousand seed weight (TSW) are the most important but complex traits affecting yield. This study undertook genome-wide association studies (GWAS) on 521 accessions of rapeseed genotyped with the Brassica 60 K SNP array by six multi-locus GWAS (ML-GWAS) and four single-locus GWAS (SL-GWAS) methods. The findings of our study showed that 280 and 31 significant quantitative trait nucleotides/loci (QTNs/QTLs) were detected above six multi-locus and four single-locus models, respectively. Among these sequences, 74 common significant QTNs were repeatedly detected by more than three ML-GWAS models and in multiple environments. Among the QTNs, 26 were detected via multiple environments, while 13 were detected via multiple methods and environments. Interestingly, 119 QTNs were detected by a single model (pLARmEB), demonstrating that this model is largely reliable and stable. However, in SL-GWAS, the GLM model detected the highest number of QTNs. The distribution of the superior allele results showed that, among 74 common significant QTNs, 28 QTNs were >50%, while 45 QTNs were <50%. The highest percentage of superior alleles indicates their probable involvement in yield-determining traits (YDTs) improvement which may facilitate marker-assisted selection. Furthermore, on the basis of common significant QTNs, 42 candidate genes were detected. We strongly believe that the genetic manipulation of these putative genes may further improve rapeseed molecular breeding for the creation of eco-friendly cultivars with improved yield. The results obtained by this strategy may lead to a breakthrough in rapeseed production at the industrial level.
显示更多 [+] 显示较少 [-]