AUTHOR=Wang Min , Yang Songguang , Liu Wei , Cao Zhenqiang , Chen Lin , Liu Wenrui , Xie Dasen , Yan Jinqiang , Jiang Biao , Peng Qingwu 

TITLE=Fine mapping and candidate gene analysis of gynoecy trait in chieh-qua (Benincasa hispida Cogn. var. chieh-qua How)

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1158735

DOI=10.3389/fpls.2023.1158735

ISSN=1664-462X

ABSTRACT=<p>Gynoecy demonstrates an earlier production of hybrids and a higher yield and improves the efficiency of hybrid seed production. Therefore, the utilization of gynoecy is beneficial for the genetic breeding of chieh-qua. However, little knowledge of gynoecious-related genes in chieh-qua has been reported until now. Here, we used an F<sub>2</sub> population from the cross between the gynoecious line ‘A36’ and the monoecious line ‘SX’ for genetic mapping and revealed that chieh-qua gynoecy was regulated by a single recessive gene. We fine-mapped it into a 530-kb region flanked by the markers Indel-3 and KASP145 on Chr.8, which harbors eight candidate genes. One of the candidate genes, <italic>Bhi08G000345</italic>, encoding networked protein 4 (<italic>CqNET4</italic>), contained a non-synonymous SNP resulting in the amino acid substitution of isoleucine (ATA; I) to methionine (ATG; M). <italic>CqNET4</italic> was prominently expressed in the female flower, and only three genes related to ethylene synthesis were significantly expressed between ‘A36’ and ‘SX.’ The results presented here provide support for the <italic>CqNET4</italic> as the most likely candidate gene for chieh-qua gynoecy, which differed from the reported gynoecious genes.</p>