The Comparative Study On The Photosynthetic Characteristics And Biochemical Compositions Metabolism Of Main Cultivars

Photosynthesis is the basis of growth of tea plant (Camellia sinensis (L.)), while the effective biochemical composition is the basis of its quality. Five main cultivars of tea plant were chose in this study. The study on the diurnal and annual variation of the photosynthesis, the annual variation of ammonia assmiliation key enzyme, the annual variation of the main biochemical compositions of five main cultivars was done. It was the aim to master the change law on the three field. The effects of photosynthesis and ammoniun assimilation key enzyme to the metabolic of the main biochemical compositions were discussed. It was concluded that:1. The diurnal change in net photosynthetic rate of 'Yingshuang' was a bimodal curve, the other four species were single peak curves. With lower light compensation point and higher light saturation point, the photosynthesis ability of 'Zhenong 139' was strongest.The next is 'Wuniuzao' and 'Zhenong 117' which light saturation point was high and light compensation point was in the middle. With higher compensation point and lower saturation point, the photosynthesis of 'Longjing 43' and 'Yingshuang' were relatively weak.The"noon break"might be the embody of its physiological rhythm. The optimum photosynthetic temperature of the tea plant which cultivated in green house was higher than that in field. Using the NLINER of SAS, the model building had greater physiological significance.2. The annual variation in net photosynthetic rate of Wuniuzao and 'Zhenong 117' were bimodal curves, the other species were single peak curves. The whole level net photosynthetic rates of five vaireties were high. The annual photosynthesis ability of 'Wuniuzao' and 'Zhenong 117' was strongest, the next were 'Zhenong 139' and 'Yingshuang', and the last was 'Longjing 43'.3. The annual change of the main biochemical compositions of different species all showed like waved, and various components were closely related with each other. In spring, the biochemical compositions were moderate. They increased at the beginning of spring and decreased at the end. The increase process also showed in summer and autumn, they were almost decreased while in winter except amino acid which decreased at the beginning of winter and increased to a higher level at the end of winter. Tea polyphenol, caffeine and amino acid were very significantly positive correlated to each other, the ratio of tea polyphenol and amino acid were mainly influenced by the tea polyphenol, and lower influenced by the amino acid.4. The changes of the biochemical compositions in summer and autumn were very significantly different, and their variation of different seasons is very different between species. The annual content of the biochemical compositions were also different from species.5. The content of biochemical compositions of 'Zhenong 139' and 'Wuniuzao' were higher than the others, and the Characters of 'Yingshuang' were poorest.6. The annual variation of the GS activity was similar to the biochemical compositions, but it increased rapidly after decreasing in winter, and it happened earlier than it of the biochemical compositions. Under the buffer of pH7.0, the GS activity was relatively high, the GS activity of root is higher in all organs.7. The change of main biochemical compositions were influenced by the annual variation of the GS activity. Especially, amino acid was rapidly response to the change of GS. The annual variation of GS and the main biochemical compositions might be limited by photosynthesis at some steps especially when photosynthesis was greatly weakened in winter.