不同颜色薄膜覆盖对越橘光合特性的影响

以越橘品种"双丰"为试验材料,采用拱棚覆膜方式,设置白膜、绿膜、红膜、黄膜、蓝膜5个处理,研究不同颜色薄膜覆盖下越橘叶片叶绿素含量、光合日变化和光响应变化差异。结果表明,绿膜覆盖下越橘叶片中叶绿素a、叶绿素b和叶绿素a+b含量显著提高,蓝膜覆盖下叶绿素a和叶绿素a+b含量显著提高,不同颜色薄膜覆盖下越橘叶片中叶绿素a/b值无显著差异。不同颜色薄膜处理下越橘叶片净光合速率(Pn)日变化曲线均为"双峰型",最高峰值均出现在8:00,Pn数值排序为蓝膜白膜红膜黄膜绿膜,不同颜色薄膜处理下越橘叶片均在11:00出现光合午休现象。气孔导度(Gs)和蒸腾速率(Tr)总体变化趋势与Pn类似,而胞间CO_2浓度(Ci)则呈"W型"曲线。通过拟合光响应曲线可知,不同处理下越橘叶片光补偿点(LCP)均降低,其中红膜和绿膜降低幅度较大。蓝膜下光饱和点(LSP)增加,且最大净光合速率(Pn_(max))最高。结果表明,蓝膜覆盖促进越橘光合作用,生产中可通过覆盖蓝色薄膜或者补充蓝光方式使越橘光合效率最大化。红膜、黄膜和绿膜对光合作用有抑制作用,但红膜和绿膜有助于增强越橘对弱光的适应能力。

Effect of different color film coverage on photosynthetic characteristics of blueberry

Taking 'Sweetheart' blueberry as material, five treatments of white, green, red, yellow and blue films were set by means of arch mulching. The effects of chlorophyll content, diurnal variation of photosynthesis and photoresponse of blueberry leaves under different color films were investigated.The results showed that the contents of chlorophyll a, chlorophyll b and chlorophyll a+b of blueberry leaves increased significantly under green film, and the contents of chlorophyll a and chlorophyll a+b of blueberry increased significantly under blue film. However, there weren't significant differences in chlorophyll a/b in blueberry leaves under different color films. The diurnal variation curves of net photosynthetic rate(Pn) of blueberry leaves under different color film treatments were all "double peak", and the highest peak of Pn appeared at a.m. 8:00, the values of Pn from high to low were blue film>white film>red film>yellow film>green film. Midday depression of photosynthesis appeared at a.m. 11:00. The stomatal conductance(Gs) and transpiration rate(Tr) showed a similar trend to Pn, while the intercellular CO_2 concentration(Ci) showed a "W-shaped" curve. By fitting the photoresponse curve, it could be concluded that the light compensation point(LCP) of the blueberry leaves decreased under different color films, and it decreased greatly under the red and green films. The light saturation point(LSP) of blueberry leaves under the blue film increased, and the maximum net photosynthetic rate(Pn_(max)) was the highest. The test results showed that blue film coverage could promote the photosynthesis of blueberry, and the photosynthetic efficiency of blueberry could maximize by covering blue film or supplementing blue light in production. The red, yellow and green films had a certain inhibitory effect on photosynthesis, but the red and green films could help to enhance the adaptability of blueberries to low light.