【作者】 莫新禄；

【导师】 赵思东；

【作者基本信息】 中南林业科技大学 ， 森林培育， 2006， 硕士

【摘要】 用LI-6400便携式光合作用测定系统对黄金梨、大果水晶梨、早生黄金梨、天皇梨、早蜜新高梨、金秋梨和晚大新高梨7个砂梨品种的光合特性进行了测定研究，并结合叶片叶绿素含量、叶片解剖结构、果实内含营养成分，以及不同环境条件下对其净光合速率的影响进行了分析。结果表明，不同砂梨品种叶片的净光合速率（Pn）不同，晚大新高梨的Pn最大值＞早蜜新高梨＞早生黄金梨＞天皇梨＞黄金梨＞大果水晶梨＞金秋梨；平均Pn值晚大新高梨＞金秋梨＞大果水晶梨＞早蜜新高梨＞黄金梨＞天皇梨＞早生黄金梨；各个品种的水分利用率（WUE）在不同时间的波动较大，7个品种的水分利用率在不同时间差异很大，不仅在数值上有一定差别，在出现峰值的时间上也各不相同。不同砂梨品种叶片的光补偿点（LCP）在10～50μmol.m^-2.s^-1之间，CO₂补偿点（CCP）在40～80μmol.mol^-1之间，品种间有一定差异；光饱和点（LSP）在1400～1520μmol.m^-2.s^-1之间，CO₂饱和点（CSP）在900～1400mol.mol^-1之间，品种间也有一定的差异。金秋梨的光饱和点最高，早生黄金梨光饱和点最低；早生黄金梨的CO₂饱和点最高，晚大新高梨的CO₂饱和点最低；金秋梨的CO₂补偿点最低，早生黄金梨的CO₂补偿点最高。不同砂梨品种叶片的羧化效率（CE）相比较，晚大新高梨最高，早蜜新高梨最低；光量子用率（AQY）相比较，金秋梨最高，早蜜新高梨最低。不同砂梨品种叶片Pn日变化曲线不同，有单峰型和不对称双峰型两种。不同砂梨品种的蒸腾速率（Tr）日变化曲线率呈单峰型，不对称双峰型和3峰型3种类型。胞间CO₂浓度（Ci）日变化曲线呈单谷型或双谷型。气孔导度（Cond）日变化曲线都呈双峰型。水分利用率（WUE）日变化曲线呈单峰型和双峰型。由于光合作用外界因素多变以及内、外因素间的相互作用构成了光合作用的影响因素的随机多变性、复杂性和不稳定性，以及有些研究只对一个或几个因素进行了简单试验和分析，有的是在室内或人工可控条件下进行，所以在不同梨树上的多因素的试验模拟和田间试验结果的综合分析还有待进一步加强和完善。更多还原

【Abstract】 In this Paper, the net Photosynthetic rate（Pn）and the diurnal variation curves of PhotoSynthesis of five different tyPes of Pear cultivars were measured by using the LI-6400—Portable Photosynthesis System.The Photosynthesis characteristics under differentcondition and of different types leaves were studied.The results showed that:The Pn of leaves were difference among these different types of Pear cultivars, the Max Pn of Wandaxingaos’leaves was highest among the 7 different kinds.The water use efficiency（WIJE） indicated complicated. The light compensation Point（LCP）and CO₂ compensation Point（CCP）of different types of pear cultivars leavesare were 10 50μmol.m^-2.s^-1 and 40 80μ.mol.mol^-1. And there were no significant difference among these cultivars, however, the LSP and CSP were 1400 1520μmol.m^-2.s^-1 and 900¹400 mol.mol^-1.The carborylation efficiency of leaves were slightly different among the 7 kinds of pears. Wandaxingao had the highest one ,Zaomixingao had the smallest one.The diurnal variation curves of Pn among different types of Pear cultivars were different, and there are two types, single—apex curve and anisomerous double—apex curve. Pear cultivars Presented single—apex curves on apirl and double—apes curves on June.The diurnal variation curves of CiPresent single—valley curves. The diurnal variation curves of Cond Present many types.Comparing different kinds of pears cultivars ,Wadaxingao pear had the max Pn and average Pn. Jinqiu pear had the second position. Other pears cultivars was little difference between each other. Jinqiu pears light compensation Point（LCP） was the lowest while Daguoshuijing was the highest. Zaoshenghuangjin pear had the lowest the Light Saturation Point （LSP）, while Daguoshuijing had the highest one. Jinqiu pear’ s CO₂ compensation Point（CCP） was the lowest, Zaoshenghuangjin pear was the highest. Wandaxingao pear ’ s CO₂ Saturation Point（CSP） was lowest, and Zaoshenghuangjin pear was the highest. Comparing to the AQY among them, Zaomixingao pear was in the lowest level, while Jinqiu pear was in the toppest level. The CE of them, Zaoshenghuangjin was the lowest, while Wandaxingao was the toppest.更多还原