题名 | 塔于南缘四种荒漠植物气体交换的季节变化 |
作者 | 邓雄 |
学位类别 | 硕士 |
答辩日期 | 2001 |
授予单位 | 中国科学院.中国科学院新疆生态与地理研究所.植物学. |
导师 | 李小明,中国科学院新疆生态与地理研究所 |
关键词 | 气体交换 |
中文摘要 | 胡杨(Poppulus euphratica Oliv)、疏叶骆驼刺(Alhagi sparsifolia B. Keller et Shap.)、多枝柽柳(Tamarix ramosissima Lbd.)和头状沙拐枣(Calligunum caput-medusae Schrenk.)等四种植物是塔克拉玛干沙漠南缘绿洲绿洲重要防风固沙植物。通过对以上四种植物同化器官气体交换响应曲线、水势、气体交换的日变化和季节变化以及同化器官稳定性碳同位素季节动态的研究,获得以下结论:1、四种植物中,头状沙拐枣的水分利用效率(WUE)最高,极杨和我枝柽柳其次,疏叶骆驼刺的水分利用效率最低。2、四种植物按光合蒸腾强弱划分为:①低光合、低蒸腾型,包括疏叶骆驼刺。②高光合、高蒸腾型,包括多枝柽柳和胡杨。③高光合、低蒸腾型,包括沙拐枣。3、四种植物对干旱适应性机理归为两类:①高水势延迟脱水抗旱机理,包括头状沙拐枣和疏叶骆驼刺。②低水势心忍耐脱水,包括多枝柽柳和胡杨。4、影响植物气体交换的环境因子中,有效辐射都是其中最重要的主导因子,其次是气温。而空气湿度主要对植物的蒸腾速率起作用。5、水分胁迫影响气温与叶温之间的差异。并提出以下问题进行探讨:1、胡析表现出一些类似C_4植物的气体交换特征。但是胡杨是否在不同环境条件、树龄及发育阶段会诱导出不同的的类C_4途径的光合特征?2、我们在用δ~(13)C表现植物WUE时发现有滞后现象,还需要进一步证实。滞后的机理、周期、以及它与外界因子的关系都值得研究。The four plants(Poppulus euphratica Oliv, Alhagi sparsifolia B. Keller et Shap.,Tamarix ramosissima Lbd., Calligunum caput-medusae Schrenk.) are important species at the southern margin of Oases of Taklimakan Desert, using for preventing drift-sand and sand storm. The photosynthetic light and CO_2 response curves were measured in field. Diurnal and seasonal changes of gas exchange, water potential(Ψ), and seasonal changes of stable carbon isotope (δ~(13)C) were studied. My results showed: 1. C. caput-medusae showed highest water use efficiency, and A. sparsifolia showed lowest water use efficiency among four plant. 2. The four desert plants can be divided into two groups according to their net photosynthesis rate(A_n) and transpiration rate(E): ①low A_n and low E, includes A. sparsifolia; ②high A_n and high E, includes P. euphratica and T. ramosissima; ③ high A_n and low E, includes C. caput-medusae. 3. The four plant were divided into two groups according to the adaptation mechanism to water stress;①Delay dehydration by high Ψ, for example C. caput-medusae and A. sparsifolia; ② Tolerate dehydration with low Ψ, for example P. euphratica and T. ramosissima. 4.Among the environmental factors, the effect of PPFD (photosynthetic photon flux density) is most significant on both A_n and E, T_a(air temperature) comes the next, RH (relative humidity) do much more with E than with A_n. 5.Water stress affects the difference between T_a(air temperature) and T_1(leaf temperature). Meanwhile, we propose two suggestions for discussion: 1.P. euphratica showed some C_4-like characteristics, but it is still a problem if it can be brought out different C_4-like characteristics in different ages, environmental conditions, or growing stages. 2. Comparing relationships between WUE and δ~(13)C of four plants among different months, the δ~(13)C showed a lag effect. More experiments are needed to test it. Furthermore, if it sound proved, we suggest the lag mechanism, the lag time and the affects of the environmental factors on the lag phenomenon are well worth studying. |
语种 | 中文 |
学科主题 | 植物生理学 |
公开日期 | 2010-11-12 |
页码 | 共40页 |
内容类型 | 学位论文 |
源URL | [http://ir.xjlas.org/handle/365004/8288] ![]() |
专题 | 新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据) |
推荐引用方式 GB/T 7714 | 邓雄 . 塔于南缘四种荒漠植物气体交换的季节变化[D]. 中国科学院.中国科学院新疆生态与地理研究所.植物学.. 2001. |
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