【作者】 陈先中；

【导师】 张银龙；

【作者基本信息】 南京林业大学 ， 生态学， 2005， 硕士

【摘要】 本文对杨树根部病害、镰刀菌分类鉴定系统及病害的发生与环境因子的关系等方面研究现状进行了概述。对近年来在苏北发生的一种新杨树病害(杨树烂根病)进行了具体研究,研究结果概述如下:　1.病害发生地及主要症状　杨树烂根病主要在我国苏北地区大面积发生。主要表现症状为:①主要危害1-3 年生幼苗,根部变黑腐烂,枝杆出现较多黑斑,有些黑斑连成条状,幼芽失水干枯;②插条腐烂,出苗率低。　　2.病原菌的分离和致病性测定　通过病菌分离,接种和致病性测定,最终获得DCF-4、DCF-8 菌株致病力较强,确定为病原菌。　3.病原菌的鉴定　通过对菌株菌落生长速率、菌落的质地、颜色和菌核、形态特征、有性阶段和产孢细胞几方面的观察和测定,根据Booth 镰刀菌分类系统确定其属镰刀菌属色变组的异孢镰刀菌种。　4.环境因子对病原镰刀菌的影响　①在24-26℃,菌丝生长最快,低到4℃和高至40℃时不生长;孢子萌发的适宜温度范围为15℃—35℃,最适温度为25℃,4℃和40℃孢子不能萌发。　②pH 值小于2.2 和强碱性,菌丝不能生长,最适pH 值范围为7.0—9.0,　pH 值8.0 时生长最好;孢子萌发的pH 值范围为5.0—10.0,最适pH 值为8.0-9.0。　③光照对此菌丝生长和孢子萌发无显著影响。　④在90%以上湿度接种,皆能发病,发病率在80%左右,其致病性无显著差异。　⑤菌丝和孢子耐低温,对高温耐性较差。　5.土壤理化性质和微生物总量与镰刀菌数量　对样地土壤各理化性质进行了测定和分析;并测定了土壤中总微生物量和镰刀菌量。　6.方差分析和显著性检验及回归分析　病害发生与土壤pH 值、土壤中总微生物量和镰刀菌量有极为显著关系;与土壤含水率、有机质含量、全氮含量、全磷和有效磷含量、速效钾含量等无显著关系。　分别以总微生物量和镰刀菌量为因变量,土壤各理化性质为自变量,进行回归分析,建立多元一次线性回归方程。并经检验,所得回归方程显著较低,即各因子之间的线性关系不是很好。更多还原

【Abstract】 The article summarize the latest study on the disease of root of Poplar, the classic systems of Fusarium and the relation between the disease and factors of environment, and study concretely a new disease of Poplar (rot roots disease of Poplar) which occurs on the north of Jiangsu province recently. The results are as follows. 1. The area of the disease and the important symptoms of the disease Reportedly, the rot roots disease of Poplar occurs on a large-scale area of the north of Jiangsu province mostly. The important symptoms of infected seedling of Poplar as follows: ①The disease harms the 1 to 3 years old seedlings mostly, the infected seedlings’root grow black and rot, many black spots on the twigs, some black spots link strip, and the buds dead for lost water. ②The cuttings rot and seedlings productivity descends. 2. The isolation, inoculation and filtration of pathogenic and pathogenicity test Through isolating fungus, inoculation and pathogenicity test, the DCF-4 and DCF-8 fungus pathogenicity are stronger than the others, they are identified to the pathogenic fungus belongs to which kind fungus and name the new disease. 3 Identification of pathogenic fungus of rot roots disease of Poplar Through observating and mensurating the growth speed of colony, the color, texture and core of the colony, the characteristics of configuration, the sexual phase, the producing cell, the pathogenic fungus is identified to belong to Discolor group and Fusarium heterosporum with the Booth system. 4. The influence of environment factors to pathogen of Fusarium ①The fungus grows rapidly cultivating from 24 to 26℃, and growth stop at 4 and 40℃. The large conidia can germinate from 15 to 35℃moderate, and can not germinate above 40℃and below 4℃. ②The fungus can not grow at pH 2.2 and strong alkalescence, and grow optimum at pH 8.0; The spore can germinate pH from 5.0 to 10.0, pH 8.0-9.0 optimum. ③Light have no much effect on the growth of fungus mycelium and spore germination. ④The pathogenicity is similar at kinds humidity above 90%, about 80%. ⑤Fungus mycelium and spore endure low temperature well, but the endurance to high temperature are not enough. 5. Mensurating and analyzing the physics and chemic index of the soil, and acquiring the microbe totality and fusarium quantity in the soil. 6. Correlation analysis and prominence test and regress analysis By correlation analysis and prominence test, the results shows as follows: the relation of the disease occurrence with the pH, the microbe totality and fusarium quantity in the soil is very obvious, with the water content of soil, organic compound content, total nitrogen content, total phosphorus and effective phosphorus content, effective kalium content is not obvious. As the same time, by regress analysis, establishing the regress equations of one power linear multivariable, the variables with the microbe totality and fusarium quantity in the soil and the independent variables with all of the soil physic and chemic characters. By prominence test, the linear relation is not obvious.更多还原