ANALYSIS ON ECOLOGICAL AND GENETIC DIVERSITY EVOLVED UNDER CULTIVATED ENVIRONMENT IN GENUS ECHINOCHLOA

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Genetic and morphological diversity was analyzed on the Echinochloa materials mainly collected from Yungui Highlands in China including species from global area in order to understand the process of adaptation such as domestication to crops and mimic weeds to specialists in cultivated fields. Isozymic and RAPD analyses indicated clearly the identity of biological species (E.crus-galli-E.esculenta complex, E.oryzicola complex, E.colonum-E.frumentacea complex), which was supported by the sequencing of non-coding region of trnT-L-F genes on cpDNA.Herbarium study, morphological evaluation at experimental farm and DNA analyses on a lot of accessions revealed the distance-dependent diversification of DNA variation (both in sequence and RAPDs), the wider distribution of domesticated traits as E.esculenta in E.crus-galli complex and the narrow distribution of domesticated traits as cultivated E.oryzicola. Specialization as weeds was found as mimic features and non-shattering habit of diaspore, which evolved as parallel in E.crus-galli complex and E.oryzicola complex. Seedling stage mimic was found in both species. Panicle mimic and auricle-like hairs on the collar of leaf sheath was particularly in E.oryzicola, which was conventionally treated as E.persistentia taxonomically. Non-shattering of diaspore was found in both complexes in the paddy fields, rainfed and irrigated paddies, and upland fields. Since this analyses also provide recognition of biological species and infraspecific taxa, and information on molecular identification technique. Further investigation on type specimen will provide delimitation of correct nomenclature name and others, which will solve the taxonomic confusion of this genus Echinochloa. The final report of this project includes 16 figures, 5 tables, 8 plates and text.