Affiliation:
1. College of Horticulture and Landscape Yunnan Agricultural University Kunming China
2. Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany, Chinese Academy of Sciences Kunming China
3. School of Agriculture Yunnan University Kunming China
4. College of Horticulture Shenyang Agricultural University Shenyang China
5. Department of Botany and Plant Pathology Oregon State University Corvallis Oregon USA
Abstract
SummaryThe strawberry genus, Fragaria, exhibits a wide range of sexual systems and natural ploidy variation. Nearly, all polyploid strawberry species exhibit separate sexes (dioecy). Research has identified the sex‐determining sequences as roughly conserved but with repeatedly changed genomic locations across octoploid strawberries. However, it remains unclear whether tetraploid wild strawberries evolved dioecy independently or shared a common origin with octoploid strawberries. In this study, we investigated the sex determinants of F. moupinensis, a dioecious plant with heterogametic females (ZW). Utilizing a combination of haplotype‐resolved genome sequencing of the female F. moupinensis, k‐mer‐based and coverage‐based genome‐wide association studies (GWAS), and transcriptomic analysis, we discovered a non‐recombining, approximately 33.6 kb W‐specific region on chromosome 2a. Within this region, only one candidate sex‐determining gene (FmoAFT) was identified. Furthermore, an extensive resequencing of the entire Fragaria genus indicated that the W‐specific region displays conservative female specificity across all tetraploid species. This observation suggests that dioecy evolved independently in tetraploid and octoploid strawberries. Moreover, employing virus‐induced gene silencing (VIGS), we knocked down the expression of the FmoAFT homologue transcript in cultivated strawberries, revealing its potential role in promoting female functions during early carpel development. We also applied DNA affinity purification sequencing (DAP‐seq) and yeast one‐hybrid assays to identify potential direct targets of FmoAFT. These insights shed new light on the genetic basis and evolutionary history of sex determination in strawberries, thereby facilitating the formulation of strategies to manipulate sex determination in breeding programs.
Funder
National Natural Science Foundation of China
Subject
Plant Science,Agronomy and Crop Science,Biotechnology