The effect of genebank seed increase on the genetics of recently collected potato (Solanum) germplasm

Abstract

In previous work at the US Potato Genebank, RAPDs were used to detect large differences between genebank-conserved samples and their correspondingin situ populations re-collected from the wild. This work investigates one possible explanation for these differences: a large genetic change in the sample when it undergoes “domestication” by a forced sexual seed increase and subsequent adaptation to cultivation in the genebank. However, when 11Solanum fendleri and 17S. jamesii populations were collected from the wild and compared to their sexual progeny generated at the genebank, no significant differences in RAPD finger-prints were detected. These results show that theory of “genebank domestication” is not supported. However, when plants of one pair of populations were tested individually, the seed increase population was significantly more heterogeneous than its clonally collectedin situ parents. Thus, while genebank populations have the same genes as their wild counterparts, they may contain genotypes not present in the wild.