Fine mapping of QTL-<i>fl3.1</i> reveal <i>SmeFL</i> as the candidate gene regulating fruit length in eggplant (<i>Solanum melongena</i> L.)
Hongtao Pang, Jiaqi Ai, Wuhong Wang, Tianhua Hu, Haijiao Hu, Jinglei Wang, Yaqin Yan, Xuexia Wu, Chonglai Bao, Qingzhen Wei
Abstract
Eggplant (<i>Solanum melongena</i> L.) is an important vegetable crop with abundant variations in fruit morphology, making it a good model for studying fruit development. In this study, quantitative trait loci (QTL) sequencing (QTL-seq) was conducted on multiple F<sub>2</sub> populations, successfully mapping the fruit length-related locus <i>fl3.1</i> on eggplant chromosome 3 (E03). Fine mapping further narrowed down this region to 106.6 kb using a large population of 968 F<sub>2</sub> plants. Within this region, a total of eight genes were identified, and <i>Smechr0302217</i> (<i>SmeFL</i>) was determined to be the most likely candidate gene through validation using RNA-seq and qRT-PCR. Sequence analysis of the parental materials revealed 12 SNPs/InDels in <i>Smechr0302217</i>, potentially accounting for the fruit length differences. Combining these findings with further cytological and transcriptomic analyses, we propose that <i>SmeFL</i> regulates fruit length by promoting cell expansion in eggplant. The identification of <i>SmeFL</i> contributes to a better understanding of the role of microtubule-associated proteins in eggplant fruit development, as well as the mechanism underlying eggplant fruit elongation.