【作者】 刘君娣；

【导师】 王有科；

【作者基本信息】 甘肃农业大学 ， 森林经理， 2007， 硕士

【摘要】 以4年生凯特、兰州大接杏、红丰三个杏树品种为供试材料,采用田间控制灌水的方法,测定了不同土壤水分条件下杏树三个品种的各项水分指标、光合特性和生化指标。旨在揭示三个品种抗旱生理机制的差异并综合评价三个品种的抗旱性强弱。对其主要抗旱生理性状进行了比较研究,结果表明:随干旱胁迫时间的延长,供试杏树叶片含水量、持水力和Va/Vs凯特明显高于兰州大接杏,兰州大接杏高于红丰;水分饱和亏凯特明显小于兰州大接杏,兰州大接杏明显小于红丰。停灌30d时,叶片蒸腾速率凯特明显低于兰州大接杏,兰州大接杏低于红丰;光合速率和水分利用率凯特明显高于兰州大接杏,兰州大接杏明显高于红丰;光合日变化凯特上午光合速率高峰值出现早且有明显的午休现象,兰州大接杏上午光合速率高峰值出现晚但有午休现象,红丰上午光合速率高峰值出现早但无明显的午休现象。从叶片含水量、相对含水量、水分饱和亏、持水力、Va/Vs、光合速率、蒸腾速率和水分利用率的变化综合分析,初步认为:供试的三个杏树品种中,凯特耐旱保水能力最强,兰州大接杏次之,红丰最弱;凯特具有高光效低蒸腾的光合特性。在干旱胁迫过程中,三个树种的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性均呈现出先升后降的变化趋势,三种植物SOD、CAT活性均在干旱处理的第20天达到最大,第20d之后三者SOD、CAT活性均呈下降趋势。凯特的SOD、CAT活性量在胁迫的整个时期高于兰州大接杏和红丰,其次为兰州大接杏,红丰最低。干旱胁迫过程中,脯氨酸的含量是逐渐增加的,在干旱处理第40d达到最大值,凯特Pro积累速度最大,其次为兰州大接杏,红丰最小。兰州大接杏和凯特的丙二醛(MDA)含量随干旱处理天数的增加呈先上升后降低之后又上升的趋势,红丰在整个胁迫期间MDA含量一直增加。从整个干旱胁迫过程中产生MDA的量的多少来看,红丰胁迫产生MDA的量显著高于其它两个品种,其次为兰州大接杏,凯特最小。三个树种的O2-·产生速率先上升后降低之后又上升,凯特在胁迫的整个过程中上升较其它两个品种缓慢,从三个品种O2-·产生的速率的量上看,凯特显著小于兰州大接杏和红丰,兰州大接杏略小于红丰,红丰最大。通过抗旱性指标的筛选和各树种的主成分分析,得出三个品种的抗旱性机理和抗旱能力起关键作用的指标几乎是一样的。通过模糊数学隶属函数法对三个品种进行综合评价,初步分析认为杏树的三个品种均具有较强的抗旱性,且三品种抗旱能力大小依次为:凯特〉兰州大接杏〉红丰。更多还原

【Abstract】 The physiological mechanism of drought-resistance in four-year Prunus armeniaca cultivars was studied, with cultivar‘Katy’, cultivar‘Hongfeng’and‘Lanzhou’as materials and under field controlling soil water environments, some mainly Biological Indices were measured in different drought stress of three cultivars, this paper mainly measure some water indexes and biochemical indexes of three cultivars in different soil water, We expected to discover difference of drought-resistance mechanism and to comprehensive evalue the droughte resistance of three cultivars. The main results are as follows:The tissue water content ,relative water content and the rate of bound water content to free water in leaves of‘Katy’was obviously higher than‘Lanzhou’, and‘Lanzhou’higher than‘Hongfeng’. The water saturation deficiency of‘Katy’was obviously lower than‘Lanzhou’, and‘Lanzhou’lower than‘Hongfeng’. With the drought-resistance of 30th day, transpiration rate of‘Katy’is lower than‘Lanzhou’, and‘Lanzhou’lower than‘Hongfeng’. The photosynthetic rate and water use efficiency of‘Katy’was obviously higher than‘Lanzhou’, and‘Lanzhou’higher than‘Hongfeng’. The results of this research showed that the peak of net photosynthesis rate of‘Katy’comes earlier than‘Lanzhou’in the morning, they all decreased at noon, showing the presence of midday depression of photosynthesis. The peak of net photosynthesis rate of Hongfeng comes earlier than‘Katy’and‘Lanzhou’in the morning,but have no obviously midday depression of photosynthesis. By analyzing results and comprehensive appraisal of all indices, the ability of drought tolerance was arranged from strong to weak as following:‘Katy’,‘Lanzhou’and‘Hongfeng’.‘Katy’with high photosynthetic rate and high water use efficiency, but transpiration rate is lower.During the stressed period, the activity of SOD and CAT increased firstly, reached the climax on the 20th day after stressed, then decreased. The activity of SOD and CAT of‘Katy’were higher than that of‘Lanzhou’and‘Hongfeng’., and‘Lanzhou’higher than‘Hongfeng’. With the activity to SOD and CAT in leaves of‘Katy’was obviously higher than‘Lanzho’u, and‘Lanzhou’higher than ‘Hongfeng’.The proline content was increased in stressed course, reached the climax on the 40th day. The increasing rate of proline of‘Katy’was higher than that of‘Lanzhou’, and‘Lanzhou’higher than of‘Hongfeng’. The content of MDA with‘Lanzhou’and‘Katy’increased firstly, reached the climax, then decreased.The content of MDA with Hongfeng. enhanced with the deeper of stressed. With content of MDA of‘Katy’was obviously higher than‘Lanzhou’, and‘Lanzhou’higher than‘Hongfeng’, the degree of velum damage of‘Hongfeng’was deeper than‘Lanzhou‘and‘Katy’in prophase of stressed.‘Katy’is lower then‘Lanzhou’. The content of of three spaces increased firstly, reached the climax, then decreased. The content of superoxide anion radical (O2-·) of‘Katy’was obviously higher than‘Lanzhou’, and‘Lanzhou’higher than‘Hongfeng’.It is considered that the mechanism of drought resistance of three cultivars is similar, and they all having strong drought resistance ability, by analyzing results of main component analysis and comprehensive appraisal of all indices. By comprehensived appraisal of all indices, the results show that the ability of drought resistance of three cultivars is:‘Katy’>‘Lanzhou’>‘Hongfeng’.更多还原