College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, China.
Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, China.
Physiol Plant. 2024 Sep-Oct;176(5):e14523. doi: 10.1111/ppl.14523.
Garlic bulbs generally possess several swelling cloves, and the swelling degree of the bulbs determines its yield and appearance quality. However, the genetic basis underlying bulb traits remains poorly known. To address this issue, we performed a genome-wide association analysis for three bulb traits: bulb weight, diameter, and height. It resulted in the identification of 51 significant associated signals from 38 genomic regions. Twelve genes from the associated regions, whose transcript abundances in the developmental bulb showed significant correlations with the investigated traits in 81 garlic accessions, were considered the candidates of the corresponding locus. We focused on five of these candidates and their variations and revealed that the promoter variations of fructose-bisphosphate aldolase-encoding Asa8G05696.1 and beta-fructofuranosidase-encoding Asa6G01167.1 are responsible for the functional diversity of these two genes in garlic population. Interestingly, our results revealed that all candidates we focused on experienced a degree of selection during garlic evolutionary history, and different genotypes of them were retained in two China-cultivated garlic groups. Taken together, these results suggest a potential involvement of those candidates in the parallel evolution of garlic bulb organs in two China-cultivated garlic groups. This study provides important insights into the genetic basis of garlic bulb traits and their evolution.
大蒜鳞茎通常具有几个肿胀的蒜瓣，鳞茎的肿胀程度决定了其产量和外观品质。然而，鳞茎性状的遗传基础知之甚少。为了解决这个问题，我们对三个鳞茎性状（鳞茎重量、直径和高度）进行了全基因组关联分析。结果在 38 个基因组区域中鉴定出 51 个显著相关信号。从相关区域的 12 个基因中，其在发育鳞茎中的转录丰度与 81 个大蒜品种中研究的性状表现出显著相关性，被认为是相应位点的候选基因。我们关注了其中的五个候选基因及其变异，并揭示了果糖-1,6-二磷酸醛缩酶编码基因 Asa8G05696.1 和β-果糖呋喃糖苷酶编码基因 Asa6G01167.1 的启动子变异是导致这两个基因在大蒜群体中功能多样性的原因。有趣的是，我们的研究结果表明，我们关注的所有候选基因在大蒜进化历史中都经历了一定程度的选择，它们的不同基因型在两个中国栽培的大蒜群体中被保留下来。总之，这些结果表明，这些候选基因可能参与了两个中国栽培的大蒜群体中大蒜鳞茎器官的平行进化。本研究为大蒜鳞茎性状及其进化的遗传基础提供了重要的见解。
