【作者】 刘勇；

【导师】 南志标；

【作者基本信息】 兰州大学 ， 植物保护学、植物病理学， 2016， 硕士

【摘要】 放牧是天然草原利用的最主要方式,草畜互作不仅影响植被及土壤,也影响植物病害的发生与发展。本研究在甘肃省环县甜水堡兰州大学草地农业科技学院放牧试验点和甘肃省甘南藏族自治州玛曲县阿孜畜牧示范园区进行,2013-2015年连续三年调查研究了不同放牧强度条件下草地植物病害的发生规律,分析了其与放牧的关系,所获主要结果如下:1、在环县和玛曲两地共发现20属25种植物病原真菌引致11科18属27种植物的35种病害。其中,在环县共发现8属10种病原真菌引致15种植物的17种病害,按各科植物发病种数由高到低的顺序,发病植物分别为豆科、旋花科、禾本科、菊科、蔷薇科、大戟科、唇形科和十字花科。常见牧草病害为胡枝子(Lespedeza bicolor)锈病(Uromyces lespedezae-procumbentis)和长芒草(Stipa bungeana)平脐蠕孢叶斑病(Bipolaris stipicola)。在玛曲共发现8科12属12种植物的18种病害,其中最常见的病害是锈病、叶斑病,分别有9和4种植物发生。按各科植物发病种数由高到低的顺序,发病植物分别为菊科、唇形科、毛茛科、禾本科、蓼科、豆科、大戟科和龙胆科。常见牧草病害为垂穗披碱草(Elymus nutans)锈病(Puccinia recondita)和垂穗披碱草离蠕孢叶斑病(Bipolaris sorokiniana)。2、发现甘肃省草类植物病害新记录10种。分别是白苞筋骨草(Ajuga lupulina)白锈病(Albugo macrospora)、垂穗披碱草锈病、独一味(Lamiophlomis rotat)锈病(P.ustalis)、高山唐松草(Thalictrum alpinum)锈病(P.rubigo-vera)、白花枝子花(Dracocephalum heterophyllum)白粉病(Erysiphe pisi)、蚓果芥(Neotorularia humilis)白粉病(E.cruciferarum)、垂穗披碱草离蠕孢叶斑病、长毛风毛菊(Saussurea hieracioides)尾孢叶斑病(Cercospora chrysanthemi)、长芒草叶斑病、珠芽蓼(Polygonum viviparum)尾孢褐斑病(Cercospora sp.)。3、放牧强度对植物病害的影响因植物和病害的种类而异,环县的放牧处理为0、2.7、5.3和8.7只羊单位/hm2,玛曲的放牧处理为0、2.7和5.3只羊单位/hm2,综合两地的研究结果,胡枝子锈病、垂穗披碱草锈病、垂穗披碱草离蠕孢叶斑病等3种病害的发病率及病情指数皆随放牧强度的增加而降低,即在0只羊单位/hm2下最高,在8.7只羊单位/hm2下最低,且在8.7只羊单位/hm2和5.3只羊单位/hm2下显著低于0只羊单位/hm2(P<0.05)。长芒草平脐蠕孢叶斑病的发病率及病情指数则随放牧强度的增加而升高,在0只羊单位/hm2下最低,在8.7只羊单位/hm2下最高,且在0只羊单位/hm2和2.7只羊单位/hm2下显著低于5.3只羊单位/hm2和8.7只羊单位/hm2(P<0.05)。而田旋花(Convolvulus arvensis)白粉病(Erysiphe convolvuli)和蚓果芥白粉病的发病率和病情指数与放牧强度无明显相关性。4、主要病害的发生与寄主植物的盖度、密度等显著相关。长芒草叶斑病、胡枝子锈病和垂穗披碱草离蠕孢叶斑病等3种病害的发病率及病情指数均与寄主植物的盖度、密度呈显著正相关(P<0.05),相关系数分别为0.923、0.802和0.765,分别可用y=0.884x+23.40,y=2.465x-4.506和y=1.625x+11.21方程式表示,其中y表示病害发病率,x表示植株密度。综上所述,从草地植物病害管理的角度,似可认为环县草原以5.3只羊/hm2、玛曲草原以2.7只羊/hm2放牧强度为宜,在此条件下,病害发病率和病情指数均低于其他放牧处理。更多还原

【Abstract】 Grazing is the most frequently measure in native grassland utilization, interactions between pasture and livestock, not only affect the grassland vegetation and soil, but also affect the occurrence and development of plant diseases. In this study, we choosed two separate sites which belongs to semi desert grassland and alpine grassland, the two sites were located at Huan county and Maqu county of Gannan,separately. The grassland plant disease occurrence under different grazing intensity of both sites were suveyed from the year 2013 to 2015, the relationship of the occurrence of plant disease and grazing intensity were analyzed. The main results obtained are as follows:1. A total of 35 fungal diseases has been found from 27 species of pasture plant which belong to 18 genera and 11 families in the two sites, the fungal pathogen belong to 25 species and 20 genera. Ten species and 8 general pathogenic fungi caused 17 disease occurred on 15 species of pasture plant in Huan Xian county, the diseased plants ranked from high to low were Leguminosae, Convolvulaceae, Gramineae, Compositae Rosaceae, Euphorbiaceae, Lamiaceae and Cruciferae, the most common diseases were rust disease(Uromyces lespedezae-procumbentis) of Lespedeza bicolor, leaf spot(Bipolaris stipicola) of Stipa bungeana. Eighteen fungal diseases occurred on 12 species and 12 generas and 8 families pasture plants were found at alpine grassland in Maqu, the most common diseases were rust disease and leaf spot, there were 9 and 4 kinds of plants infected, respectively. The diseased plants ranked from high to low were Compositae, Lamiaceae, Ranunculaceae, Gramineae, Polygonaceae, Leguminosae, Euphorbiaceae and Gentianaceae. The most common diseases were rust disease(Puccinia recondita) of Elymus nutans, leaf spot(Bipolaris sorokiniana) of Bipolaris sorokiniana.2. Among the 35 fungal diseases, ten species of the disease were first found in Gansu province. They are white rust(Albugo macrospora) of Ajuga lupulina, rust disease(Puccinia recondita) of Elymus nutans, rust disease(P.ustalis) of Lamiophlomis rotat, rust disease(P. rubigo-vera) of Thalictrum alpinum, powdery mildew(Erysiphe pisi) of Dracocephalum heterophyllum, powdery mildew(E. cruciferarum) of Neotorularia humilis, leaf spot(Bipolaris sorokiniana) of E. nutans, leaf spot(Cercospora chrysanthemi) of Saussurea hieracioides, leaf spot(B. stipicola) of Stipa bungeana, brown spot(Cercospora sp.) of Polygonum viviparum.3. The effects of grazing on plant diseases varied with the species of plant and plant diseases, the grazing treatments of Huan county are 0, 2.7, 5.3 and 8.7 sheep/hm2, the grazing treatments of Maqu county are 0, 2.7 and 5.3 sheep/hm2, intergrating the research results of two sites, the incidence and disease index of rust of L. bicolor and E. nutans and leaf spot of E. nutans was decreased with the increasing of stocking rates, the values were highest under 0 sheep/hm2 while lowest under 0 sheep/hm2, and the values were significantly lower under 8.7 sheep/hm2 and 5.3 sheep/hm2 compared with the treatment of 0 sheep/hm2(P<0.05). The incidence and disease index of leaf spot of S. bungeana was increased with the increasing of stocking rates, the values were lowest under 0 sheep/hm2 and highest under 8.7 sheep/hm2, the values of disease incidence and disease index were significantly lower under 0 sheep/hm2 and 2.7 sheep/hm2 than that under 5.3 sheep/hm2 and 8.7 sheep/hm2(P<0.05). However, the incidence and disease index of powdery mildew of Convolvulus arvensis and Neotorularia humilis have no significant relativity with the changing of stocking rates.4. The occurrence of major diseases significantly related to the coverage and density of host plants. The incidence and disease index of 3 pasture plant diseases includ rust of L. bicolor, E. nutans, leaf spot of S. bungeana and E. nutans, were significantly positively related to hosts coverage and density(P<0.05), the correlation coefficient were 0.923, 0.802 and 0.765, respectively. The relationship could be expressed by using the equations y=0.884x+23.40, y=2.465x-4.506 and y=1.625x+11.21, ―y‖means disease incidence, ―x‖ means plant density.In a summary, from the view of grassland plant diseases management, the 5.3 sheep/hm2 treatment and 2.7 sheep/hm2 treastments seems the most optimal grazing intensity in Huanxian and Maqu grassland respectively, which given the lowest disease incidence and disease index across the treatments.更多还原