【作者】 苏秀红；

【导师】 强胜；

【作者基本信息】 南京农业大学 ， 植物学， 2005， 博士

【摘要】 紫茎泽兰(Eupatorium adenophorum Spreng.)原产于中美州的墨西哥，自20世纪40年代入侵我国以来，迅速在我国西南地区扩展蔓延，并对当地的农、林牧业造成极大的危害。该草入侵新的生境后能够迅速扩展蔓延，并强烈排挤其它植物的生长，在生态系统中逐渐占据主导地位，甚至形成大面积的单优势种群，这与其强的生态适应能力密切相关。但国内外对紫茎泽兰的研究主要集中在其生物学特性、危害及防除方面，有关其不同分布范围种群对逆境适应性差异的研究还鲜有报道。本文以采自分布范围不同的紫茎泽兰为研究材料，在干旱和高温胁迫下比较其适应性，目的是筛选鉴定出耐性、敏感种群试图进一步从生理生化角度揭示其生态适应性差异的原因。 通过相对发芽率、萌发抗旱指数、活力指数3个指标，研究了14个不同地理种群紫茎泽兰的耐旱能力，并采用模糊隶属法对14个不同种群的耐旱性进行了综合评价。发现不同地理种群紫茎泽兰耐旱性存在一定的差异。云南罗平、四川攀枝花、云南元江种群较为耐旱，耐旱隶属函数总平均值分别0.766、0.689、0.658；云南思茅种群则较为敏感，耐旱隶属函数总平均值为O.065。 采用人工模拟气候法、模糊数学中隶属函数法(测定了净光合速率、丙二醛、光化学效率)比较了17个不同种群紫茎泽兰的耐热性。结果表明高温处理后云南元江与其他种群相比热害指数最低、隶属函数值较高，最为耐热，其次为云南元谋种群；而云南大理种群1热害指数较高，隶属函数均值也较低。其次为广西隆林，被认为是敏感种群。结合其生境来看，恶性杂草紫茎泽兰种群之间的这种差异性反映了其对入侵地环境的适应性。 以耐热性强的云南元江和差的云南大理种群1及介于中间的云南曲靖、贵州黄果树等4个种群为材料进一步研究了它们不同发育时期(二叶一心期、三叶一心期、四叶一心期)、不同温度(35℃、40℃、45℃)处理及黑暗条件下的耐热性，结果表明3-4叶期紫茎泽兰能够反映各种群耐热性。与35℃相比，40℃、45℃高温处理能在较短时间内区分出各种群的耐热性。但在相同时间处理内45℃高温处理植株伤害较重，各种群形态区分不如40℃处理明显。黑暗高温处理与光照条件相比，各种群受害较为严重。处理48h后各种群叶片几乎全部变褐死亡。 进一步测定了40℃高温胁迫0h、8h、16h及再常温恢复6h后，上述耐热性不同的4更多还原

【Abstract】 Crofton weed (Eupatorium adenophorum Spreng.) was one of the most noxious invasive weeds in the world. Since it was firstly introduced to China in the 1940s, it had spread rapidly throughout the southwestern China including Yunnan, Guizhou, Guangxi, Sichuan and even to Hubei Provinces. Its invasion had caused serious economic consequences for agriculture, forestry and husbandry and had become one of the worst weeds in these regions. It inhibited indigenous plant growth and thus replaced desirable native species, which may be related to its strong ecological adaptation. However, the study on crofton weed was mainly focused on its biological characteristics, harmness and controlling. Few works have been done on its ecological adaptation. Osmotic potentials (PEG6000), chamber test and asubordinate function value test were used to evaluate their drought-resistence or heat-tolerance among different populations of the Eupatorium adenophorum Spreng in order to select and identify different resistance populations in this paper. Then on the basis of these study, different heat-tolerance populations were employed to study their response to high temperature stress.Relative germination percentage, promptness index, vigor index of crofton weed from 14 populations were tested under different osmotic potentials (PEG6000) to evaluate their drought resistance using the fussy subordinative function. The results showed that there were differences in drought-resistance among the populations tested. Luoping of Yunnan Province, Panzhihua of Sichuan Province and Yuanjiang of Yunnan Province had the relative higher drought resistance while Simao of Yunnan Province had lower resistance. The total of average subordinative value of the former three populations with resistance to drought stress were 0.766, 0.689, 0.658, while the later susceptible to drought stress was更多还原