烟田垄体走向对烤烟不同部位叶片光合特性的影响

摘要

Taking flue -cured tobacco variety Yunyan 97 as the tested material, the photosynthetic characteristics of tobacco leaves in three positions ( bottom, middle and top) and in three ridge- directions (southeast- northwest, south- north, east- west) were investigated in the field experiment in Pengshui county of Chongqing city in 2010.The results indicated that the net photosynthetic rate (Pn), stomatic conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of the top leaves all showed southeast-northwest ridge-direction ＞ east-west ridge-direction ＞ south-north ridge-direction, and the vapour pressure deficit (Vpd) showed south - north ridge - direction ＞ southeast - northwest ridge - direction ＞ east - west ridge - direction.Gs, Ci and Tr of the middle leaves exhibited east - west ridge - direction ＞ south - north ridge - direction ＞ southeast - northwest ridge - direction.Pn and Ci of the bottom leaves revealed south - north ridge - direction ＞ southeast - northwest ridge - direction ＞ east- west ridge-direction.Leaf temperature (Tl) and photosynthetic active radiation (PAR) of the top, middle and bottom leaves all showed southeast - northwest ridge - direction ＞ south - north ridge - direction ＞ east - west ridge - direction.Vpd of the middle leaves and Tr and Vpd of the bottom leaves had similar trends with Tl and PAR.Pn of the leaves in different ridge - directions all exhibited the top leaves ＞ the middle leaves ＞ the bottom leaves, Gs had a similar changeable trend with Tr, while Ci and PAR had different changeable trends each other, and there were no significant differences in Tl and Vpd among different position leaves.%以云烟97为试验材料,2010年在重庆市彭水县布置田间小区试验,研究3种垄体走向(东南-西北垄、南北垄和东西垄)对烤烟下、中、上3个部位叶片光合特性的影响.结果表明:上部叶位的光合速率、气孔导度、胞间二氧化碳浓度和蒸腾速率均表现为东南-西北垄＞东西垄＞南北垄,而蒸汽压亏缺则为南北垄较高,东南-西北垄次之,东西垄较低.中部叶位的气孔导度、胞间二氧化碳浓度和蒸腾速率则为东西垄＞南北垄＞东南-西北垄.下部叶位的光合速率和胞间二氧化碳浓度为南北垄＞东南-西北垄＞东西垄.烤烟上、中、下3个部位叶片叶温和有效光辐射均表现为东南-西北垄＞南北垄＞东西垄.中部叶位的蒸汽压亏缺、下部叶位的蒸腾速率和蒸汽压亏缺则与叶温和有效光辐射变化趋势一致.不同垄体走向下烟叶各部位叶片的光合速率均表现为上部叶＞中部叶＞下部叶,气孔导度和蒸腾速率表现相似,胞间二氧化碳浓度和有效光辐射表现各异,叶温和蒸汽压亏缺各部位表现差异不大.