|Del rio, Alfonso|
Submitted to: American Journal of Potato Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/3/2003
Publication Date: 5/15/2003
Citation: Del Rio, A.H., Bamberg, J.B. 2003. The effect of genebank seed increase on the genetics of recently collected potato (Solanum) germplasm. American Journal of Potato Research. 80:215-218. Interpretive Summary: Potato genebanks are concerned with preserving genetic diversity, so naturally want to know how the diversity in the genebank compares to that present in nature. Genebank samples collected decades ago had been found to be genetically different than their corresponding current populations in nature. How did this change occur? Perhaps the process of adapting wild plants to the artificial genebank environment caused the genetic change. When wild plants were compaed to their offspring generated at the genebank, however, very little genetic difference was detected. So the process of 'domesticating' wild samples by adapting them to genebank conditions does not appear to cause genes to be lost, and genebank managers need not change their techniques. We did find, however, that gene combinations within individual plants may differ in the wild and in the genebank, so scientists who work with these materials should not assume that the characteristics plants express are exactly the same in both places.
Technical Abstract: In previous work at the US Potato Genebank, large differences were detected when genebank-conserved samples were compared, with RAPDs, to correcponding in 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. Our results show that this explanation is not supported, since very little difference was detected in the presence of bands in bulk samples of these paired populations. However, when plants of one pair of populations were tested individually, the seed increase population was significantly more heterogeneous than its clonally-collected in situ parents. Thus, while genebank populations have the same genes as their wild counterparts, they may contain genotypes not present in the wild.