Plant & Animal Genome IX Conference Plant & Animal Genome IX Conference
Workshop: Fruit/Nut Tree
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A linkage map of the diploid strawberry, Fragaria vesca, has provided a foundation for two inter-related avenues of strawberry genetic research: 1) identification and cloning of horticulturally important genes, and 2) investigation of the phylogenetic relationships among the various diploid and polyploid Fragaria species. A summary of our research in these two areas will focus primarily on the following: 1) Using a candidate gene approach, we have determined the likely molecular identity of the yellow fruit color (c) locus in F. vesca. Concomitantly, PCR-detectable intron length polymorphisms were identified in five enzyme-encoding genes and one regulatory gene of the anthocyanin biosynthesis pathway, and the map locations of these six genes were determined. Primers and probes developed in this study will be useful for investigating the genetic basis of fruit color variation in the octoploid, cultivated strawberry, F. x ananassa. 2) Using a novel technique - S1 nuclease analysis of long PCR heteroduplexes - to scan the highly conserved strawberry chloroplast genome, we have identified phylogenetically informative indel polymorphisms that provide the basis for construction of a chloroplast genome (maternal lineage) phylogeny in Fragaria. Strawberry-specific chloroplast genome sequence needed for PCR primer design was acquired by random sequencing of clones from a strawberry chloroplast genomic library. Comparative sequencing of introns from anthocyanin pathway and other nuclear genes, combined with the chloroplast phylogeny, will allow construction of a comprehensive species phylogeny for Fragaria.