RAPD analysis of genetic diversity in Solanum populations to predict need for fine screening

Populations of two wild potato species known to have high levels of green peach aphid, PLRV, and PVY resistance (Solanum polytrichon PI 184170 and S. stoloniferum PI 160226) were assessed for heterogeneity of RAPD markers among plants within these populations and among other populations of the same species. These species are reputed selfers, so were suspected of being relatively inbred, About 75% of the bands segregating within their species were fixed within these populations, and more than 90% of the total bands observed within these populations were fixed. These levels of homogeneity were not significantly different from those of an inbred population of S. albicans known to be extremely homogeneous, It can be expected that populations such as these, that are relatively homogeneous, are also more likely to be homogeneous for specific traits of interest, Thus, there may be less need for rigorous fine screening of these materials at the genotype level before making breeding crosses.