Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Marilyn L. Warburton x
Clear All Modify Search

Previous studies of peach germplasm using pedigree information and isozyme polymorphism data have shown limited diversity in the U.S. gene pool. To further investigate the genetic diversity among peach cultivars grown in different regions of the United States, 94 RAPD markers were used to estimate the genetic distances among 136 cultivars. Of the 12 clusters formed in a dendrogram, the 90 U.S. cultivars and breeding lines and most of those from Europe and Latin America grouped to only three clusters, while the 23 peach entries from India, Pakistan, Russia, Okinawa, and China, as well as the almond cultivar used as an outgroup, were distributed among the other nine clusters. Therefore, the genetic diversity within temperate U.S. peach germplasm is quite limited, and to expand the variability, additional germplasm should be obtained, especially from Asia. Comparison of genetic similarity based on inbreeding coefficients with similarity coefficients based on the RAPD data produced a correlation of 0.395, which is comparable to values in similar investigations in other crops. Thus, similar conclusions can be drawn from these two sources of information. RAPD data are useful particularly when pedigree information is incomplete, there has been substantial selection within breeding populations, and a high proportion of alleles are identical in state but not by descent.

Free access

Genetic linkage maps for many organisms are being produced using molecular markers. The utility of these maps depends on the ability to place genes of known, important effects on the map. It is often useful lo saturate the chromosome around these loci with many linked molecular markers. This study used Bulked Segregant Analysis and Random Amplified Polymorphic DNA to identify linked markers to loci in peach, Prunus persica L. Batch and almond Prunus dulcis Mill populations. Linkages to isozyme loci were first sought to test the suitability of this technique to long-lived perrenials. Several RAPD markers were found to be linked to three isozyme loci in a segregating F3 population from a peach × almond cross. PAPD markers have also been identified which are linked to the yellow-flesh locus of peach in a heterozygous peach population. Thus, this method has proven useful for identifying molecular marker linkages to important loci in peach and almond. These RAPDs may now be placed on a linkage map generated in our lab using a peach/almond hybrid population which will allow these loci to be studied and manipulated more easily in a breeding program.

Free access