New Fagopyrum species revealed by morphological and molecular analyses

Nine Fagopyrum accessions which are suspected to be new species were examined for morphology and crossability with their closely related species. Three accessions similar to F. leptopodum are considered to be members of F. leptopodum because of no difference in 14 qualitative characters examined and fertility of hybrids between them. One accession similar to F. gracilipes is included in F. gracilipes by the same reason. Two other F. gracilipes-like accessions are considered to be a new species based on morphological differences and sterility of hybrids. Three accessions related to F. pleioramosum and F. callianthum had characters different from both species and could not be included into either species. Phylogenetic relationships among the suspected accessions and related species were examined based on isozyme variability and nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA). The accessions considered to be new species were distantly related to the group of their related species in the molecular phylogenetic trees. In contrast, those accessions considered to be F. leptopodum and the accession considered to be F. gracilipes based on morphological characters and crossability were included in the respective group of their related species. Thus these molecular phylogenetic trees support the classification based on morphology and crossability.