Abstract: The study on the photosynthetic characteristics and dry matter accumulation of twelve hybrid rice varieties in the eco-environments with low- and high light intensity showed that the adaptation ability of the varieties to eco-environment was mainly depended on the varieties themselves, and there existed greater differences among them. The differences in net photosynthetic rate (P_n) and chlorophyll content (Chl) were more significant among the varieties than between the eco-environments. The grain yield had significant positive correlations with P_n and total dry matter mass (TDM), the etermination coefficientR² being 0.584 and 0.590, respectively, but no significant correlations with the export percentage of the matter in stem-sheath (EPMSS) and the transformation percentage of the matter in stem-sheath (TPMSS). In the eco-environment with high light intensity, the leaf thickness and dry matter accumulation increased, while the EPMSS and TPMSS decreased. Under enough sunlight condition, the high proportion of matter in grain yield was mainly come from the photosynthesis at late growth stages; while under insufficient sunlight condition, it was mainly originated from the early growth stages photosynthesis.

Key words: niche, interspecific association, major species, shrimp, the offshore waters of southern Zhejiang Province