PDF(Pubmed)
Abstract：
The root systems of Brassica species are complex. Eight root system architecture (RSA) traits, including total root length, total root surface area, root average diameter, number of tips, total primary root length, total lateral root length, total tertiary root length, and basal link length, were phenotyped across 379 accessions representing six Brassica species (B. napus, B. juncea, B. carinata, B. oleracea, B. nigra, and B. rapa) using a semi-hydroponic system and image analysis software. The results suggest that, among the assessed species, B. napus and B. oleracea had the most intricate and largest root systems, while B. nigra exhibited the smallest roots. The two species B. juncea and B. carinata shared comparable root system complexity and had root systems with larger root diameters. In addition, 313 of the Brassica accessions were genotyped using a 19K Brassica single nucleotide polymorphism (SNP) array. After filtering by TASSEL 5.0, 6,213 SNP markers, comprising 5,103 markers on the A-genome (covering 302,504 kb) and 1,110 markers on the C-genome (covering 452,764 kb), were selected for genome-wide association studies (GWAS). Two general linear models were tested to identify the genomic regions and SNPs associated with the RSA traits. GWAS identified 79 significant SNP markers associated with the eight RSA traits investigated. These markers were distributed across the 18 chromosomes of B. napus, except for chromosome C06. Sixty-five markers were located on the A-genome, and 14 on the C-genome. Furthermore, the major marker-trait associations (MTAs)/quantitative trait loci (QTLs) associated with root traits were located on chromosomes A02, A03, and A06. Brassica accessions with distinct RSA traits were identified, which could hold functional, adaptive, evolutionary, environmental, pathological, and breeding significance.
摘要：
芸苔属物种的根系是复杂的。八个根系架构(RSA)特征，包括总根长度，总根表面积，根平均直径，提示数量,总主根长度，总侧根长度，总三级根长度，和基础链接长度，在代表六个芸苔属物种的379个种质中进行了表型分析(B.napus,B.commoea,B.Carinata,B.oleracea,B.Nigra,和B.rapa)使用半水培系统和图像分析软件。结果表明,在评估的物种中，甘蓝型油菜和甘蓝有最复杂和最大的根系，而黑芽孢杆菌表现出最小的根。两种B.juncea和B.carinata具有相当的根系复杂性，并且具有较大根直径的根系。此外,使用19KBrassica单核苷酸多态性（SNP）阵列对313个芸苔属种质进行了基因分型。通过TASSEL5.0，6,213个SNP标记过滤后，包括A基因组上的5,103个标记（覆盖302,504kb）和C基因组上的1,110个标记（覆盖452,764kb），被选入全基因组关联研究(GWAS)。测试了两个一般线性模型以鉴定与RSA性状相关的基因组区域和SNP。GWAS鉴定出79个与所研究的8个RSA性状相关的显著SNP标记。这些标记分布在欧洲油菜的18条染色体上，除了C06染色体.在A基因组上有65个标记，和14个在C基因组上。此外，与根性状相关的主要标记性状关联（MTA）/数量性状基因座（QTL）位于染色体A02，A03和A06上。鉴定了具有不同RSA性状的芸苔属种质，可以保持功能，适应性，进化，环境,病态,和育种意义。
