AUTHOR=Yang Wenrui , Wang Peng , Liu Ting , Nong Lifeng , Cheng Zhikui , Su Liwen , Bai Wenhui , Deng Yan , Chen Zhihao , Liu Zhengguo 

TITLE=Fine mapping of the major gene BhHLS1 controlling seed size in wax gourd (Benincasa hispida)

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1266796

DOI=10.3389/fpls.2023.1266796

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction/Background</title><p>The seed size of wax gourds is an important agronomic trait; however, the associated genes have not yet been reported.</p></sec><sec><title>Methods</title><p>In this study, we used a high-density genetic map constructed based on F<sub>8</sub> recombinant inbred line populations derived from a cross between MY-1 (large seed) and GX-71 (small seed) strains to detect quantitative trait locis (QTLs) for seed-size-related traits in wax gourd over a two-year period.</p></sec><sec><title>Results</title><p>Two stable QTLs (<italic>qSL10</italic> and <italic>qSW10</italic>) for seed length (SL) and seed width (SW) on chromosome 10 were repeatedly detected over two years (2021–2022). <italic>qSL10</italic> had a phenotypic variation rate of 75.30% and 80.80% in 2021 and 2022, respectively. Whereas, <italic>qSW10</italic> had a phenotypic variation rate of 66.60% and 73.80% in 2021 and 2022, respectively. Further, a single nucleotide polymorphism mutation was found to cause early termination of <italic>Bch10G006400</italic> (<italic>BhHLS1</italic>) translation in GX-71 through sequencing analysis of candidate genes. Based on gene functional annotation and quantitative real-time PCR analyses, <italic>BhHLS1</italic> encoded a probable N-acetyltransferase HLS1-like protein and its expression level was significantly different between parents. Therefore, <italic>BhHLS1</italic> is a major candidate gene associated with a one-factor polymorphism regulating the SL and SW of wax gourds. Finally, based on variation in the <italic>BhHLS1</italic> sequence, a cleaved amplified polymorphic sequence marker was developed for the molecular marker-assisted breeding of wax gourds.</p></sec><sec><title>Discussion</title><p>Overall, this study is of great significance for the genetic improvement of seed size, verification of gene functions, and cultivation of specific germplasm resources for wax gourds.</p></sec>