【作者】 刘文婷；

【导师】 胡庭兴；

【作者基本信息】 四川农业大学 ， 森林培育学， 2009， 硕士

【摘要】 本试验以中国四川可河、美国菲尼克斯和澳大利亚肯多伯冷（分别以Z₁、Z₂和Z₃表示）3个种源地的希蒙得木（Simmondsia chinensis（Link） Schneider）一年生实生幼苗为研究对象,采用盆栽控水的方法,研究3个种源希蒙得木幼苗在干旱胁迫下的生长、生理生化指标变化规律,并对其抗旱性进行综合评价,为希蒙得木的合理栽培提供科学依据,同时为选育具有较强抗旱能力的希蒙得木种源提供参考。试验研究结果如下:1.干旱胁迫下,3个种源的高生长均受到了抑制,随着干旱胁迫程度的加重,苗高相对生长量呈显著下降趋势。2.3个种源叶片相对含水量（LRWC）随着干旱胁迫程度的加重而减少,下降幅度为:Z₁＞Z₃＞Z₂,土壤含水量是影响LRWC的重要因子。3.干旱胁迫下3个种源的保护酶系统活性总体呈上升趋势。Z₃的SOD活性增加幅度最大,Z1的POD、CAT活性增加幅度最大。Z₃的MDA含量总体呈上升趋势,Z₁、Z₂变化不明显。4.干旱胁迫下3个种源的渗透调节物质含量均呈上升趋势。脯氨酸和可溶性糖含量的上升幅度为Z₁＞Z₂＞Z₃。5.干旱胁迫下,3个种源的净光合速率、蒸腾速率、气孔导度、叶绿素含量、PSⅡ原初光能转换效率、PSⅡ潜在活性等指标均显著下降。Pn、Tr、Gs下降趋势大致相同,下降幅度均为Z₃＞Z₂＞Z₁,叶绿素总含量的下降幅度为Z₁＞Z₃＞Z₂,Fv/Fm、F_V/F₀的下降幅度为Z₃＞Z₁＞Z₂。6.干旱胁迫下Z₃的希蒙得木幼苗最先死亡,3个种源致死点的土壤含水量为5.51%～6.26%,耐旱致死点时间与土壤含水量呈负相关。7.干旱胁迫下,希蒙得木幼苗各抗旱指标产生不同变化以抵御逆境,表明希蒙得木具较强耐旱性。利用主成分分析和模糊隶属函数法综合评价了3个希蒙得木种源的抗旱性,抗旱能力由强到弱依次为:中国会东可河（Z₁）,美国菲尼克斯（Z₂）,澳大利亚肯多伯冷（Z₃）。更多还原

【Abstract】 The study was carried out by one-year-old potted seedlings ofjojoba（Simmondsia Chinensis（Link） Schneider） from Kehe in Sichuan of China,Phoenix in USA and Condobolin in Australia（represented by Z₁,Z₂ and Z₃ respectively）.The characteristics of drought resistance of 3 jojoba provenances were studied by analyzing the regularity for changes of growth,physical and chemical indexes under drought stress,which helped to provide scientific bases for rational cultivation of jojoba and a reference for selecting and brdeeding the jojoba provenance which has comparatively stronger ability in drought resistance.The main results are as following:1.The relative height growth of all the 3 provenances were restrained under drought stress,which showed significant downtrend.2.The LRWC of 3 provenances declined with the aggravation of drought stress,the decrease was Z₁＞Z₃＞Z₂.Soil moisture is the important facto for LRWC.3.The activities of the protecting enzyme System of the 3 provenances had ascended under drought stress.The activity of SOD of Z₃ increased the most,the activity of CAT and POD of Z₁ increased the most.The content of MDA of Z₃ had been ascending under drought stress,there was no appreciable changing trend in Z₁ and Z₂.4.The content of osmotic regulatory metabolites of the 3 provenances ascended as a whole under drought stress.The increase amount of PRO contents and soluble sugar were: Z₁＞Z₂＞Z₃.5.Net photosynthesize,transpiration rate,stomata conductance,chlorophyll content, energy conversion of PSⅡ,potential activities of PSⅡhave been descending with the degree of soil drought increasing.Pn、Tr、Gs decreased with aggravation of drought stress in the same way:Z₃＞Z₂＞Z₁.The chloropyll content decreased:Z₁＞Z₃＞Z₂.Fv/Fm、F_v/F₀ decreased:Z₃＞Z₁＞Z₂.6.The seedling of jojoba of Z₃ died firstly,the deathpoint of soil water content is 5.51%～6.26%.There was negative correlation between the deathpoint and the soil moisture.7.Under drought stress,different changes in drought indexes of jojoba seedlings in order to resist adversity.These showed that jojoba had strong drought tolerance. Comprehensive evaluation of drought resistance of jojoba from 3 provenances was given based on principal components analysis and fuzzy subordination function analysisi method. The drought resistance abilities order（from strong to weak） was Kehe in Sichuan of China,Phoenix in USA and Condobolin in Australia.更多还原