Fine mapping of QTL-fl3.1 reveal SmeFL as the candidate gene regulating fruit length in eggplant (Solanum melongena L.)

Abstract

Eggplant (Solanum melongena 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 F2 populations, successfully mapping the fruit length-related locus fl3.1 on eggplant chromosome 3 (E03). Fine mapping further narrowed down this region to 106.6 kb using a large population of 968 F2 plants. Within this region, a total of eight genes were identified, and Smechr0302217 (SmeFL) 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 Smechr0302217, potentially accounting for the fruit length differences. Combining these findings with further cytological and transcriptomic analyses, we propose that SmeFL regulates fruit length by promoting cell expansion in eggplant. The identification of SmeFL 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.

Keywords

• eggplant
• fruit length
• qtl-seq
• fine-mapping
• rna-seq