Genetic background of an invasive Lolium population in central Japan using chloroplast DNA and SSR markers

Kurokawa S, Kobayashi H & Ikeda K (2010). Genetic background of an invasive Lolium population in central Japan using chloroplast DNA and SSR markers. Weed Research50, 245–252.Summary To determine the genetic background of an invasive population of Lolium spp., we compared three non-coding regions of chloroplast DNA (cpDNA) and nine SSR loci of the population with those of 30 cultivars of Lolium multiflorum, Lolium perenne or their hybrid and two accessions of Lolium rigidum. For the cultivars and L. rigidum, bulked DNA was used for all analyses, due to variations within cultivars. Two of three regions in cpDNA were polymorphic among samples, generating four haplotypes (A–D). We found haplotypes A and B in L. multiflorum and L. rigidum, and haplotypes C and D only in L. perenne. All 48 individuals of the invasive population were discriminated as haplotype A, suggesting annual maternal origin. Nine loci of SSR generated 55 alleles in total in the invasive population. The presence or absence of these 55 alleles was counted for the bulked DNA of cultivars and L. rigidum. There were significant differences among species in the correspondences of alleles with those of the invasive populations. The correspondence of alleles with L. multiflorum was significantly higher than that with L. perenne or L. rigidum. These results suggested that the genetic background of the invasive population was very close to L. multiflorum. Although common traits among cultivars genetically close to the invasive population were not found, the wide variation in allele correspondence among L. multiflorum cultivars may indicate that non-invasive cultivar breeding may be possible in the future.