草莓短日型和日中型品种全基因组重测序变异比较研究OA

To elucidate the molecular genetic mechamisms underlying the continuous-flowering trait in strawberries and provide a theretical foundation for molecular breeding,a comparative analysis of genomic variations was conducted through whole genome resequencing to systematically investigate the genetic basis underlying the divergence in flowering habits between short-day(seasonal flowering)and day-neutral(perpetual flowering)strawberry(Fragaria×ananassa)cultivars.Three short-day cultivars(Akihime,Xuelixiang,and Kaorino)and three day-neutral cultivars(Portola,Albi-on,and San Andreas)were selected for high-throughput sequencing using the Illumina platform.The sequencing reads were aligned to the Fragaria vesca reference genome for subsequent genomic analysis.A higher overall number of genetic variants was observed in day-neutral cultivars compared to short-day cultivars,with a notably increased density of poly-morphisms detected on chromosome 4.Analysis of insertions and deletions(InDels)revealed that a greater number of In-Dels were present in day-neutral genotypes,among which 37.21％were identified as frameshift mutations within coding regions,suggesting potential impacts on protein function.Structural variations(SVs)were examined,and a higher preva-lence of exonic SVs was found in day-neutral accessions(25.46％)than in short-day accessions.Functional annotation of the variant sets demonstrated significant enrichment of genes associated with phytohormone signal transduction,circadi-an rhythm,and biosynthesis of secondary metabolites.Gene ontology(GO)classification indicated that these genes were primarily involved in metabolic processes,catalytic activity,and membrane-related functions.Notably,18 circadian rhythm-associated genes—including GIGANTEA,phy B,and EARLY FLOWERING 3—were identified as carrying nonsynonymous single-nucleotide polymorphisms(SNPs)or frameshift InDels that were specific to day-neutral culti-vars.These genes were considered central components of the photoperiodic flowering regulatory network.Significant en-richment of these genes was further validated by KEGG pathway analysis in pathways related to plant-environment inter-action and circadian rhythm.This study provides the first genome-scale evidence that continuous flowering in day-neutral strawberries is achieved through the accumulation of structural variants in key regulatory genes,leading to modifications in photoperiodic signaling pathways.These findings offer novel insights into the molecular mechanisms governing flower-ing time variation in strawberry and establish a foundation for marker-assisted breeding strategies aimed at developing cul-tivars adapted to diverse photoperiodic conditions.