【作者】 尚卓婷；

【导师】 栾雨时；

【作者基本信息】 大连理工大学 ， 作物遗传育种， 2008， 硕士

【摘要】 自我国开展越橘引种工作到大规模产业化种植的过程中,越橘病害也随之发生,目前已发现的越橘病害主要分为侵染性病害和生理性病害两大类。侵染性病害以真菌性叶斑病发病最早,侵染面最广;而生理性病害以土壤缺素现象最为常见。本实验从病害发生严重的种苗繁育基地采集病叶标本,经分离纯化获得一株真菌,用涂抹法接种健康同种越橘植株叶片,得到与自然发病相同的症状,符合柯赫法则。首先根据该病原菌的菌落特征、显微镜下的菌丝和孢子体的形态结构进行鉴定,初步确定为拟盘多毛孢属。其次通过PCR扩增得到ITS和β-tubulin的部分核酸序列,登陆GenBank进行比对分析,准确鉴定该致病菌为棒孢拟盘多毛孢(Pestalotiopsis clavispora)。该工作确立了一种真菌型病害的准确鉴定方法。此外,选取健康越橘叶片,分离得到其内生真菌,根据形态学特征初步筛选出两种真菌,并对扩增得到的ITS序列分析后确定是钩状木霉(Trichoderma hamatum)和球状毛壳菌(Chaetomium globosum)。钩状木霉菌的10%、20%、30%发酵液对棒孢拟盘多毛孢的抑菌率分别为52.69%、67.31%、78.31%;球状毛壳菌的相应抑菌率为69.19%、74.47%、83.36%。对峙生长实验也证明这两种菌对棒孢拟盘多毛孢有很好的抑菌效果。此外对钩状木霉产几丁质酶活性的抗病机理和两种菌的生理特性也进行了研究。通过对这两种菌的分离鉴定为有效抑制棒孢拟盘多毛孢提供了一种潜在的生物防治途径。采用蛭石为栽培基质,将营养液中镁离子浓度在0.2—10 mmol/L范围内设计六个梯度适时补给越橘苗。两个月后,1—2.5mmol/L处理的植株生长正常。而高浓度处理的叶片出现焦枯,低浓度处理的叶片变黄或变红。通过对生长量、叶片光合参数和叶绿素含量等的综合分析得出基质中镁离子浓度为1.5mmol/L时最适于越橘苗生长,正常生长时叶片中镁元素的质量浓度在0.095%—0.11%范围内。上述实验为越橘苗镁元素的营养诊断及合理施加镁肥奠定了基础。更多还原

【Abstract】 The planting of blueberry in China has been industrialized on a massive scale since it was introduced from abroad.However,during this process,blueberry related diseases also occurred.So far,two major types of diseases have been discovered,infective disease and physiological disease.Among all kinds of infective disease,the leaf spot infected by fungi pathogen has the earliest onset and widest spread,while nutritional deficiency symptoms of soil is the most common one of physiological disease.The research is about new blueberry leaf spot disease in Dalian,Liaoning province of China.Separated and purificated one strain fungi from lesions of leaf and Koch’s postulates were fulfilled.With morphological observation,ITS andβ-tubulin sequences’ identification, we got a result as the blueberry leaf spot disease’ pathogen was Pestalotiopsis clavispora in Liaoning Province.This establishes a method to identify fungi pathogen.Then endophytic fungus which were isolated from the Blueberry were chosen preliminarily.Through ITS sequences’ identification,they were Trichoderma hamatum and Chaetomium globosum.The control rate of zymotic fluid of 10%,20%,30%by T.hamatum were 52.69%,67.31%, 78.31%and the same to C.globosum number were 69.19%,74.47%,83.36%.Inhibiting rates of T.hamatum and C.globosum against P.clavispora by method of flat paired culture also proved to be effective.Furthermore,we tested that T.hamatum can produce antifungal chitinase and investigated physiology characters both of them.This work could provide a potential method of biological control against P.clavispora.Blueberry is planted within nutrient fluid which has vermiculite and six different levels of Magnesian Ion concentration between 0.2 mmol/L and 10 mmol/L.Two months later,we discovered that the plant grew appropriately in the nutrient fluid with the level of 12.5mmol/L, and high level results to curled exsciccation of leaves while low level leads to chlorosis.By testing the growth of plants,photosynthetic parameter,chloroplast pigment and conductivity,we reached the conclusion that ground substance of 1.5 mmol/L magnesium concentration is best for the growth of blueberry and the mass concentration should be between 0.095%to 0.11%.This experiment laid the foundation of Magnesian nutrition diagnosis and rational application of Magnesian fertilizer.更多还原