GENETIC-LINKAGE BETWEEN RUNNERING AND PHOSPHOGLUCOISOMERASE ALLOZYMES, AND SYSTEMATIC DISTORTION OF MONOGENIC SEGREGATION RATIOS IN DIPLOID STRAWBERRY

As part of a strawberry (Fragaria sp.) genome mapping project, we studied the linkage relationship between runnering and phosphoglucoisomerase PGI-2 allozymes in diploid strawberry. The respectiver and Pgi-2 loci were found linked with a recombination frequency of 18.1% +/- 1.6% (a map distance of 18.9 +/- 1.6 cM). This is the second reported linkage in strawberry. The linkage between runnering and phosphoglucoisomerase allozymes, if conserved at the octoploid level, might provide a means of marker-assisted selection for the nonrunnering and bushy branching growth habits in cultivated strawberry. Severe distortion of monogenic segregation ratios was observed for runnering and PGI-2, and also for an unlinked locus for shikimate dehydrogenase allozymes. Alleles from the perpetual flowering (alpine F. vesca) parents were favored in this distortion. This phenomenon should be considered in future genetic studies using crosses between alpine and nonalpine strawberries.