大田条件下模拟UV-B辐射滤减对白肋烟形态和光合指标的影响

Effects of simulated reduced ultraviolet-B radiation on morphology and photosynthesis in burley tobacco under field conditions

在恩施烟区大田条件下,以白肋烟品种‘鄂烟6号’为试验材料,研究了UV-B辐射滤减处理对烟株外部形态、生物量、光合色素和光合作用的影响.结果表明:UV-B辐射滤减处理显著增加了白肋烟叶片长度和烟株叶面积指数;T2、T3处理的叶面积指数较对照分别增大了9.25%和6.19%;提高了烟株叶面积指数和地上部生物量;叶绿素a和叶绿素b含量增加,类胡萝卜素含量显著下降,改变了不同光合色素之间的比值,即叶绿素a/叶绿素b值增大,叶绿素/类胡萝卜素值显著增大;T2、T3处理的叶片净光合速率、蒸腾速率、气孔导度较对照增大.说明适度的UV-B辐射滤减对白肋烟外部形态和光合能力有促进影响.

Burley tobacco （cv. ‘Eyan 6＇） was used as materials for study the effects of simulated reduced ultraviolet-B radiation on morphology, biomass, photosynthetic pigments and photosynthesis under field conditions in Enshi tobacco-growing areas. The results showed that UV-B radiation attenuated significantly increased the leaf length, T2, T3 treatment leaf area increased by 9.25 % and 6.19 %,improved tobacco leaf area index and aboveground biomass, enhanced the content of chlorophyll a （Chla） and b （Chlb）, lowered the content of carotenoids and altered the ratio between different photosynthetic pigments, increased the ratio of chlorophyll a and b,and the ratio of chlorophyll and carotenoids significantly increased for T2 treatment. The net photosynthetic rate of reduced ultraviolet-B radiation treatment was lower than contrast in early growing period, but higher than contrast in later growing period, transpiration rate and stomatal conductance were higher than contrast. It is suggested that control of ultraviolet-B radiation reduced is important on external forms and photosynthetic capacity in burley tobacco.