Title: A study of resources of Fagopyrum (Polygonaceae) native to China
Abstract: Morphology, taxonomy, reproductive biology, esterase isozyme patterns and chromosome number were studied in 16 accessions of cultivated and wild buckwheat native to Tibet, Sichuan, Guizhou and Yunnan. Among these are four established species: Fagopyrum esculentum, F tataricum, F. pleioramosum and F gracilipes. The first three species are diploid (2n = 16) and the last one is tetraploid (2n = 32). In addition to the above, three new species are described: F. zuogongense, F. megaspartanium and E pilus. There are clear differences in esterase isozyme patterns between these species. The zymographs of esterase isozyme of diploid F. megaspartanium (native to Sichuan) and F. pilus (native to Tibet) are similar to those of F. esculentum and F tataricum respectively. F. gracilipes, in the small achene group of the genus, has a zymograph of esterase isozyme that is very different from the species in the large-achene group. The diploid accessions of F. pilus and F. megaspartanium may be ancestors of cultivated buckwheat.