DNA preservation and utility of a historic seed collection

Abstract

AbstractHistoric collections of biological material are important genetic resources for taxonomic, evolutionary and historical research. In this paper we describe a seed collection dating from 1862 to 1918 maintained at the Swedish Museum of Cultural History. The collection contains over 3000 well-documented seed samples of various agricultural crops, mostly cereals. A subset of 100 samples divided over ten species frequently represented in the collection and a range of ages were tested for germinability and DNA preservation. None of these accessions were found to contain viable seeds. DNA extracted from the seeds was degraded, but the amount of degradation varied between species. DNA quality was evaluated by yield, fragment size and size of amplification product. Quality was highest for DNA extracted fromPisum sativumandVicia sativa. DNA extracted fromBrassica napus,Beta vulgarisandTrifolium pratensewas more fragmented, and DNA extracted fromTriticum aestivum,Secale sereale,Hordeum vulgare,Avena sativaandPhleum pratensewas most degraded. Polymerase chain reaction (PCR) amplification of ribosomal DNA fragments of up to 700 bp was permitted for most samples in all species. To test whether single-copy nuclear genes could be amplified from the extracted DNA, microsatellite markers were used on thePisum sativumandHordeum vulgaresamples. Polymorphisms of microsatellite markers were detected between samples for both species. The results show that the 19th-century seed collection can be utilized to infer genetic relationships among obsolete cultivars as well as for other types of genetic research based on sequence or marker analysis.