ARS | Publication request: Assessment of Putative Identical Germplasm Collections at Cip and Us Potato Genebanks Determined by Rapd and Ssr Markers

Submitted to: Potato Association Of America Proceedings
Publication Acceptance Date: April 15, 2004
Publication Date: August 10, 2004
Citation: Del Rio, A.H., Bamberg, J.B., Huaman, Z. 2004. Assessment Of Putative Identical Germplasm Collections At Cip And Us Potato Genebanks Determined By Rapd And Ssr Markers [abstract]. Potato Association Of America Proceedings. Paper No. G14.

Technical Abstract: Cooperative efforts among members of the Association of Potato Inter-Genebank Collaborators (APIC) yielded a global inventory of wild potato genetic resources that is freely available to researches and breeders. In that database it is often found that a number of accessions were originated from distributed progeny of a single original germplasm collection. Thus, the logical assumption is that although these samples are allocated in different locations, they should be genetically equivalent. This study tested this hypothesis by comparing 22 pairs of accessions of 18 different potato species, which are reputed duplicates preserved in the potato genebanks of The International Potato Center (CIP) in Peru and NRSP-6 in The United States of America. The RAPD analysis found that even though the average genetic similarity of reputed duplicates was quite high (98.1%); there were 6 with significant differences. Similarly, SSR markers identified 4 reputed duplicates that were genetically different. Co-dominant expression of SSR markers showed that loss of heterozygosity occurred at some loci, a probable indication of genetic drift. The most extreme case was in S. berthaultii (3 loci). Of the 5 total loci that became homozygous, 4 were observed in the CIP populations. Thus, researchers working with germplasm should be aware that while samples under the same identifier in different genebanks are similar, they might not be identical