A genetic linkage map of microsatellite, gene-specific and morphological markers in diploid Fragaria.
Diploid Fragaria provide a potential model for genomic studies in the Rosaceae. To develop a genetic linkage map of diploid Fragaria, we scored 78 markers (68 microsatellites, one sequence-characterised amplified region, six gene-specific markers and three morphological traits) in an interspecific F2 population of 94 plants generated from a cross of F.vesca f. semperflorens x F. nubicola. Co-segregation analysis arranged 76 markers into seven discrete linkage groups covering 448 cM, with linkage group sizes ranging from 100.3 cM to 22.9 cM. Marker coverage was generally good; however some clustering of markers was observed on six of the seven linkage groups. Segregation distortion was observed at a high proportion of loci (54%), which could reflect the interspecific nature of the progeny and, in some cases, the self-incompatibility of F. nubicola. Such distortion may also account for some of the marker clustering observed in the map. One of the morphological markers, pale-green leaf (pg) has not previously been mapped in Fragaria and was located to the mid-point of linkage group VI. The transferable nature of the markers used in this study means that the map will be ideal for use as a framework for additional marker incorporation aimed at enhancing and resolving map coverage of the diploid Fragaria genome. The map also provides a sound basis for linkage map transfer to the cultivated octoploid strawberry.
East Malling Research, New Road, East Malling, West Malling, Kent ME19 6BJ, UK. dan.sargent@emr.ac.uk
D J
DJ
Sargent
T M
TM
Davis
K R
KR
Tobutt
M J
MJ
Wilkinson
N H
NH
Battey
D W
DW
Simpson
D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods; D032461:Chromosomes, Plant / Q000235:genetics; D017931:DNA Primers; D004171:Diploidy; D031985:Fragaria / Q000235:genetics*; D005819:Genetic Markers; D018895:Microsatellite Repeats
D017931:DNA Primers; D005819:Genetic Markers