Evaluation of Flooding Tolerance in Echinochloa Species

Flooding tolerance is a critical adaptive trait which allows Echinochloa species to compete with rice in paddy field. It is known that growth pattern to the flooding responses at early stage is quite distinct, indicating that Echinochloa species exhibit different flooding response from dry to wet to flooding. Using morphological and physiological aspects, flooding diversity in six Echinochloa species, three Korean Echinochloa species, E. oryzicola, E.crus-galli var. crus-galli, E. crus-galli var. praticola and three American Echinochloa species, E. phyllopogon, E. oryzoides, E.crus-galli, were investigated. We performed partial and complete flooding treatment at 2^nd leaf stage for 30 days, and observed E.oryzicola and E.crus-galli var. crus-galli had greater tolerance to flooding stress than E. crus-galli var. praticola in Korean species. All three American Echinochloa species showed strong adaptation to flooding response, indicating there is less variation in flooding tolerance. These results will serve as an initial step toward future transcriptomic analysis for flooding tolerance among Echinochloa species.