AUTHOR=Niu Jianqing , Chen Qiong , Lu Xiaonan , Wang Xueqiang , Tang Zhongli , Liu Qinghua , Lei Fengjin , Xu Xiaoyong 

TITLE=Fine mapping and identifying candidate gene of Y underlying yellow peel in Cucurbita pepo

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1159937

DOI=10.3389/fpls.2023.1159937

ISSN=1664-462X

ABSTRACT=<p>As a conspicuous trait, peel color is one of the most important characteristics that affects commodity quality and consumer preferences. The locus <italic>Y</italic> underlying yellow peel in <italic>Cucurbita pepo</italic> (zucchini) was first reported in 1922; however, its molecular mechanism is still unknown. In this study, a genetic analysis revealed that yellow peel is controlled by a single dominant genetic factor. Furthermore, <italic>Y</italic> was mapped in a ~170 kb region on chromosome 10 by bulked segregated analysis (BSA) and fine mapping in F<sub>2</sub> and BC<sub>1</sub> segregating populations. The candidate region harbors fifteen annotated genes, among which <italic>Cp4.1LG10g11560</italic> (<italic>CpCHLH</italic>) is regarded as a promising candidate gene. <italic>CpCHLH</italic> encodes a magnesium chelatase H subunit involved in chlorophyll biosynthesis, and its mutation can result in a reduction in chlorophyll content and yellow phenotype. Interestingly, a large fragment (~15 kb) duplication containing incomplete <italic>CpCHLH</italic> was inserted in the candidate interval, resulting in two reformed CpCHLH proteins in the yellow parental line. It is most likely that the reformed CpCHLH proteins act as a malfunctional competitor of the normal CpCHLH protein to interrupt the formation of chlorophyll. Overall, the isolation of <italic>Y</italic> will shed light on the molecular mechanism of the peel color regulation of zucchini and lay a foundation for breeding.</p>