Among the three cultívars of tea, Assam hybrids had a relatively higher net photosynthetic rate (P^) than the China and Cambod types. Though the leaves selected for chlorophyll (Chl) estimation were physiologically mature and identical, wide range of shades in the colour of leaves was observed. No significant difference between cultívars was notíced in Chl (a + b) content, but distinct difference was obtained among certain dones. Chl atb ratío exhibited significant difference between both the cultívars and dones.
The effects of selenium on photosynthesis and Chl fluorescence in pear, grape, and peach were analyzed. The foliar spray of amino acid-chelated selenium solution was performed soon after fruit setting, totally six times, with an interval of ten days. After seven days from the last spray, the leaves in the middle of shoots were examined. Foliar spray of selenium increased the net photosynthetic rate in pear, grape, and peach. In contrast, the treatment decreased stomatal conductance, transpiration rate, and substomatal CO2 concentration in all the three species. The selenium treatment improved the maximum quantum yield of PSII, effective quantum yield of PSII, and photochemical quenching in all three species. Conversely, the selenium treatment reduced nonphotochemical quenching in all three species. We suggested that selenium can improve photosynthesis and protect PSII in fruit crops., T. Feng, S. S. Chen, D. Q. Gao, G. Q. Liu, H. X. Bai, A. Li, L. X. Peng, Z. Y. Ren., and Obsahuje seznam literatury