[Restriction fragment length polymorphisms of chloroplast DNA and the intergenic spacer of rRNA gene in cultivated barley of China].

A sample of 80 accessions collected from several major barley growing areas in China was assayed for restriction fragment length polymorphisms at two regions of the chloroplast DNA and the intergenic spacer of the ribosomal RNA gene (rDNA). The results showed that the spacer length was highly polymorphic and 8 spacer length variants constituting 8 phenotypes were observed in this sample. It is also clear that the spacer length variants and the phenotypes were differentially distributed in different geographical regions, probably due to adaptation of the genotypes to the local environments. We did not detect variation in the two chloroplast fragments, indicating that the variability of chloroplast DNA is low in cultivated barley.