【作者】 黄锦湖；

【导师】 吴承祯； 洪伟；

【作者基本信息】 福建农林大学 ， 生态学， 2009， 硕士

【摘要】 磷作为植物生长发育的必需元素之一,在人类赖以生存的生态系统中起着不可替代的作用,但磷素不足已成为限制目前世界农林业产量的重要因素。通过挖掘和利用植物自身营养性状的遗传特异性,运用生理生化指标的研究手段,改良和筛选耐低磷的植物品种以适应不利的环境条件,是一条高产高效的新途径。迄今为止,对于雷公藤(Tripterygium wilfordii Hook.F.)的研究更多地集中在其成分结构、药理作用等医药方面,而对雷公藤人工栽培技术、生理、生态机理研究,以及影响雷公藤生长发育的主要立地因子等报道较少。本文通过土培途径,设计不同的磷素胁迫试验,在磷素胁迫条件下测定雷公藤的形态学和生理学指标,比较雷公藤对不同程度的磷素胁迫的形态学和生理学响应,揭示雷公藤通过形态学和生理学特性的改变来调节自身养分吸收的机理,以及雷公藤不同部位有效物质的浓度和含量的变化,求出施磷肥的投入产出效益最大化需磷量,为雷公藤的合理经营提供依据。(1)不同年龄的雷公藤的生长均受低磷胁迫的显著影响,但不同年龄雷公藤对低磷胁迫响应不同。一年生雷公藤对低磷胁迫反应十分敏感,随着胁迫程度的加重,各项指标迅速下降,不适合在低磷土壤中生长;三年生雷公藤能够通过自身的调整,一定程度上适应低磷环境。(2)雷公藤对缺磷环境有较强的调节适应能力,在低磷水平的林地上可保持一定的叶绿素含量,从而保证植株光合作用和有机物质的形成。低磷胁迫条件下,雷公藤光合作用受阻,表现为:蒸腾速率下降,叶绿素含量降低,光合速率下降。光合作用强弱反映了植株磷营养状况,光合作用可以作为植物磷状况的一个生理指标。(3)磷胁迫严重影响了不同年龄雷公藤的形态指标:低磷胁迫条件下,雷公藤的地径、最长枝、株高生长受阻,干物质累积量减少,根冠比增加。(4)低磷胁迫条件下,植物体内SOD、CAT、POD等保护酶活性以及MDA含量、脯氨酸含量会发生相应变化:不同年龄的雷公藤在低磷条件胁迫下,SOD活性、MDA含量均大幅度提高;CAT、POD活性下降。不同年龄的雷公藤脯氨酸含量变化不同:一年生雷公藤叶片脯氨酸含量上升的同时,三年生雷公藤叶片脯氨酸含量下降。同一处理条件下,10月份和7月份相比脯氨酸含量、SOD酶活性、MDA含量,POD活性上升;CAT活性下降。这些变化可以反映植物在逆境条件下的生理变化情况,对研究植物的逆境伤害和抗逆机制具有重要的意义。(5)土壤酶活性可以反映土壤肥力的总水平,通常土壤酶活性高说明养分有效性高。在低磷胁迫条件下,不同年龄雷公藤根际土壤的过氧化氢酶活性、蔗糖酶活性、脲酶活性下降。10月份和7月份相比,过氧化氢酶活性、蔗糖酶活性、脲酶活性下降。(6)在低磷胁迫条件下,不同年龄的雷公藤根部、枝干雷公藤甲素含量均下降,且随着胁迫程度加重,下降幅度增大。随着雷公藤的生长,枝干和根部的雷公藤甲素含量均上升,但磷胁迫影响了甲素的积累。(7)雷公藤生理指标的季节变化,还表现出对高温、高光照强度的适应性。如通过气孔会关闭,使蒸腾减弱,伴随着绿素含量的降低。更多还原

【Abstract】 Phosphorus is a key element for plant growth, it plays an irreplaceable role on the ecosystem that human survives in. However, the problem of insufficient phosphorus has become the main factor that influences the production of agricultural and forestry. The research of low-phosphorus stress adaptation Tripterygium wilfordii physiological and biochemical mechanism is of great practical significance.Up to date, the research of Tripterygium wilfordii is mostly on the structure of its constituents, Pharmacological effects, such as medicine, while the report about its artificial cultivation technology, physiological and ecological mechanism, and the factors that effect the growth of Tripterygium wilfordii is relative few. By the soil culture, the design of low- phosphorus stress test, the morphological and physiological response of Tripterygium wilfordii to different levels of low-phosphorus stress, this paper revealed the mechanism of its regulation to the absorption of phosphorus through the morphological and physiological changes, as well as the changes of concentration of Tripterygium wilfordii wilfordii Hook.F. in different parts of triptolide, providing the basis for its rational management.1) Low-phosphorus stress significantly affected the growth of triptreygium with different ages, and the response of Tripterygium wilfordii with different ages to low-phosphorus stress was different. One-year Tripterygium wilfordii was very sensitive to low-Phosphorus stress, as the degree of stress increased, the parameters declined rapidly, and it was not suitable for it to grow in low phosphorus soil. To some extent, three-years Tripterygium wilfordii can adjust itself to adapt to low phosphorus environment.2) Tripterygium wilfordii has a strong ability to adapt the environment with insufficient phosphorus, it can maintain a certain content of chlorophyll in the forest with low phosphorus, this can ensure the photosynthesis of plant and the formation of organic substance. Under the conditions of low-phosphorus stress, the photosynthesis of Tripterygium wilfordii was blocked, it can be showed as: the transpiration rate was reduced, the content of chlorophyll was down and the rate of phosphorus was declined. The degree of photosynthetic reflected the nutritional status of the plant, thus it can be used as a physiological indicator of phosphorus.3) Phosphorus stress seriously affected the morphological index of Tripterygium wilfordii with different ages: In order to grow better under the conditions of low-Phosphorus stress, the growth of Tripterygium wilfordii’s diameter, the longest branches, and height was hindered. As the severity of phosphorus was increased, the content of dry matter of Tripterygium wilfordii with different ages was reduced and the root-shoot ratio was increased. The patterns indicators are the important judge for the nutritional status of plant.4) Under the low-Phosphorus stress, the activities of protective enzyme like SOD, CAI and POD, the content of MAD of proline in the plant would change correspondingly: both of the activity of SOD and the content of MDA increased apparently, and the activity of CAT ANT and POD decreased. The changes of the content of proline were different in the Tripterygium wilfordii with different ages: while the content of proline in the leave of one-year Tripterygium wilfordii was increased, the content of proline in the leave of three-years Tripterygium wilfordii was decreased. Under the same processing condition, compared to July , the content of proline and MDA , the activity of SOD and POD were increased , and the activity of CAT was decreased in October. This can reflect the physiological changes of plant in the adverse condition, and is significant to research of plant’s stress injury and the resistance mechanism.5) The activity of soli enzyme may reflect the general level of soil fertility, usually the high activity of soli enzyme shows the high nutrient of soli.Under low-Phosphorus stress, the activity of catalase, sucrose and urease in the athe of Tripterygium wilfordii with different ages were decreased. Compared to July, the activity of catalase, sucrose and urease were decreased in October.6) Under the low-Phosphorus stress, the content of triptolide in the root and branches of Tripterygium wilfordii with different ages was decreased, and it would be decreased more apparently as the degree of the low-Phosphorus stress was streng then. As the growth of Tripterygium wilfordii, the content of triptolide in branches and roots were both increased, but the low-Phosphorus stress affected the accumulation of triptolide.7) The seasonal changes of physiological indicators in Tripterygium wilfordii also appeared in the adaptation to the high temperature and high light intensity. For instance, as the stomata closed,the transpiration would be decreased, and the content of chlorophyll would be reduced.更多还原