ARS | Publication request: ASSESSING CHANGES IN THE GENETIC DIVERSITY IN POTATO GENEBANKS

Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: May 16, 1996
Publication Date: N/A

Technical Abstract: The Association of Potato Intergenebank Collaborators (APIC) has initiated a joint research project to investigate the effects of seed increases on the genetic integrity of germplasm conserved ex situ, and whether germplasm in genebanks still represents the in situ populations from which they were collected. RAPD markers were used to establish genetic relationships between various generations of the same accession increased in the genebank, and between these populations and samples currently growing in situ at their original collection sites in nature. Solanum jamesii (2n=2x=24) and S. fendleri (2n=4x=48) were used as models representing two major breeding systems found among wild potato species. In both species, populations separated by one generation and sister populations generated from a common original source were never significantly different and averaged >96% similarity. In contrast, significant genetic differences were found between genebank-conserved and populations collected from original wild sites 14-35 years later. Average similarity was only 65% for S. jamesii (all comparisons significantly different), and 80% for S. fendleri (about half of the comparisons significantly different). Our results showed that although current ex situ seed increase procedures cause only minor genetic changes, there might be major differences between ex situ and in situ populations due to natural evolution in the latter.