AUTHOR=Cheng Cheng , Fan Yu , Tang Yu , Zhang Kaixuan , Joshi Dinesh C. , Jha Rintu , Janovská Dagmar , Meglič Vladimir , Yan Mingli , Zhou Meiliang 

TITLE=Fagopyrum esculentum ssp. ancestrale-A Hybrid Species Between Diploid F. cymosum and F. esculentum

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.01073

DOI=10.3389/fpls.2020.01073

ISSN=1664-462X

ABSTRACT=<p><italic>Fagopyrum cymosum</italic> is considered as most probable wild ancestor of cultivated buckwheat. However, the evolutionary route from <italic>F. cymosum</italic> to <italic>F. esculentum</italic> remains to be deciphered. We hypothesized that a hybrid species exists in natural habitats between diploid <italic>F. cymosum</italic> and <italic>F. esculentum</italic>. The aim of this research was to determine the phylogenetic position of <italic>F. esculentum</italic> ssp. <italic>ancestrale</italic> and to provide new thoughts on buckwheat evolution. Different methodologies including evaluation of morphological traits, determination of secondary metabolites, fluorescence <italic>in situ</italic> hybridization (FISH), comparative chloroplast genomics, and molecular markers were deployed to determine the phylogenetic relationship of <italic>F. esculentum</italic> ssp. <italic>ancestrale</italic> with <italic>F. cymosum</italic> and <italic>F. esculentum</italic>. The ambiguity observed in morphological pattern of genetic variation in three species revealed that <italic>F.</italic><italic>esculentum</italic> ssp. ancestrale is closely related to <italic>F. cymosum</italic> and <italic>F. esculentum</italic>. Flavonoid analysis revealed that <italic>F.</italic><italic>esculentum</italic> ssp. <italic>ancestrale</italic> is closely related to <italic>F. esculentum</italic>. Comparative chloroplast genome analysis further supported the close proximity of <italic>F. esculentum</italic> ssp. <italic>ancestrale</italic> with <italic>F. esculentum</italic>. Additionally, molecular marker analysis revealed that <italic>F. esculentum</italic> ssp. <italic>ancestrale</italic> exhibits co-dominance with the bands amplified by <italic>F. cymosum</italic> and <italic>F. esculentum</italic>. These finding provided supporting evidence in favor of the hypothesis that <italic>F. esculentum</italic> ssp. <italic>ancestrale</italic> is a hybrid species between <italic>F. cymosum</italic> to <italic>F. esculentum</italic>, which was probably originated by spontaneous hybridization under natural conditions.</p>