The provenance difference for photosynthetic characters of Taxus chinensis var.mairer seedling was studied by use of provenance trial under different shading condition located at Chun'an of Zhejiang.The result indicated that there were obvious provenance differences for height growth,dry matter accumulation,chlorophyll a,b and the total content,photosynthesis rate with different geographical genetic variation pattern.Seedling height was found to be positively and significantly related to the altitude and longitude of its seed source.Contrasting to seedling height,dry matter appeared to be certainly and negatively related to the altitude and longitude of its seed source.There were no obvious geographical variation pattern for chlorophyll content and photosynthesis rate.The provenances with more chlorophyll had higher photosynthesis rate and greater dry matter accumulation.Analysis demonstrated that there existed great effect of light environment on photosynthetic character of seedling.At September,the chlorophyll a,b and total content of the seedlings under light transmittance 10% were 12.0%,16.1% and 13.7% more than the ones under light transmittance 25% respectively.At October,the chlorophyll a,b and total content of the most provenances were declined under light transmittance 10%,and average photosynthesis rate of the provenances tested was 13.7% less than the one under light transmittance 25%. The change of chlorophyll content of provenance seedling at various growth stages varied with light condition.Under light transmittance 25%,the content of chlorophyll was lower at August,highest at September,and decreased or increased slightly at October.Under light transmittance 10%,the content of chlorophyll at October was descended above 20% than one at September.
