Genetic variability in Erianthus arundinaceus accessions native to Japan based on nuclear DNA content and simple sequence repeat markers

Erianthus arundinaceus, part of the Saccharum complex, is increasingly important as a bioenergy crop and a potential resource for sugarcane improvement. Germplasm is widely distributed in the tropical zone in Southeast Asia and southern China, and has been found in the subtropical and temperate zones in Japan. Here, we investigated the 2C DNA content and simple sequence repeat (SSR) polymorphisms in E. arundinaceus accessions native to Japan. To estimate DNA content, flow cytometric analysis was performed on accessions collected from three climatic zones (temperate, subtropical, and tropical) in Japan and Indonesia. DNA content ranged from 7.42 to 8.10 pg (mean 7.62 pg), and all examined accessions fell into two groups reflecting collection location: the temperate zone in Japan (mean 8.06 pg) and the subtropical and tropical zones in Japan and Indonesia (mean 7.56 pg). Although DNA content differed significantly between the accessions from temperate and tropical/subtropical zones, chromosome number was inferred to be identical in all accessions. A phylogenetic tree of 42 accessions in the Saccharum complex based on detected fragments from 31 SSR primer pairs classified Erianthus and related genera into well-defined distinct groups. Thus, both 2C DNA content and phylogenetic analysis subdivided the E. arundinaceus accessions into two groups, suggesting that some of the Japanese accessions had different genetic characteristics from other accessions from Japan and Indonesia.