烤烟叶片光合气体交换参数对滤减UV-B辐射强度的响应

以烤烟品种'K326'为试验材料,通过覆盖不同的透明薄膜滤减UV-B辐射处理方式,并应用多元统计的岭回归分析方法,研究了100%(CK)、75%(A)、50% (B)、35%(C)自然UV-B辐射处理下烤烟成熟初期叶片的光合气体交换参数与50 cm和150 cm高度UV-B辐射强度的关系.结果表明:对于净光合速率,不同高度的UV-B辐射对A、B、C处理的抑制强度都是A>C>B;3个处理的瞬时水分利用效率(WUE)受UV-B辐射抑制强度为B>C>A;在A、C处理条件下,影响烟叶净光合速率变化的主要是气孔因素,而B处理条件下却主要是非气孔因素.可见,'K326'烤烟叶片的光合气体交换参数对不同的UV-B辐射强度响应区间的敏感性存在一定的差异.

Response of Photosynthetic Gas Exchange Parameters of the Leaves of Flue-cured Tobacco on the Attenuated UV-B Radiation Intensity

By covering different transparent membrane to filter UV-B radiation and using the method of ridge regression analysis,we studied the relationship between the photosynthetic gas exchange parameters of tobacco cultivar 'K326' at its early maturity stage and the UV-B radiation intensity at the heights of 50 and 150 cm when the UV-B transmittances were 100%(CK),75%(A),50% (B) and 35%(C).The results showed that:for net photosynthetic rate,the ordinal relation of inhibition rate of 'K326' under the treatments of A,B and C to different UV-B radiation intensities was A>C>B.The inhibition rate of water use efficiency of the tobacco in three treatments was B>C>A.The most important reason for the change of tobacco net photosynthetic rate in A and C were both stomatal factor and in B was nonstomatal factors.The research showed that the sensibility of photosynthetic gas exchange parameters of the leaves of tobacco at different intervals of UV-B radiation intensity differed.