【作者】 印敬明；

【导师】 高克祥； 刘晓光；

【作者基本信息】 山东农业大学 ， 植物病理学， 2007， 硕士

【摘要】 螺旋毛壳(Chaetomium spirale Zopf.)ND35是从健康毛白杨中分离得到的优势内生菌。本文通过对ND35在实验室、温室及大田等条件下,针对番茄、菜豆和黄瓜等几种蔬菜植物的防病、促生效果及其机制进行了初步研究,为今后生产中开发利用该生防菌提供理论依据。平皿对峙试验及显微观察结果表明,ND35对番茄灰霉病菌(Botrytis cinerea, Pers.)、番茄早疫病菌(Alternaria solani)、黄瓜猝倒病菌(Pythium aphanidermatum)、菜豆立枯病菌(Rhizoctonia solani)等病原真菌的生长具有不同程度的抑制作用,生长抑制率分别为54.0﹪,13.5﹪,55.1﹪和40.9﹪。对峙培养后期,ND35菌丝生长覆盖病原菌菌落,并伴随菌丝缠绕等重寄生现象。温室条件下,将ND35接种于黄瓜、番茄和菜豆幼苗根部,3d左右即能在根部定殖,7 d扩展到茎部、叶部。显微观察结果显示,无菌条件下ND35在48 hr~72 hr内即可完成对番茄和黄瓜胚根的侵染,菌丝穿透寄主细胞壁进入细胞。两种实验结果大致相同。ND35在番茄幼苗上定殖后,具有明显的促进植株生长的作用。幼苗株高、根长、地上部及根部鲜重都明显高于对照。对番茄幼苗中后期第3、4真叶净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)等各项光合作用指标进行测定,结果表明ND35能够提高番茄幼苗的净光合速率(Pn)。大田栽培条件下,ND35对番茄产量的提高,具有一定的促进作用,生长中期植株可见花数、座果数分别比对照高75.8﹪和22.7﹪,单株平均产量比对照高14.5﹪。温室内盆栽试验结果显示,ND35与Rhizoctonia solani同时接种于菜豆幼苗根部,对菜豆立枯病的防治效果达到50.9﹪;ND35接种黄瓜幼苗根部3 d后,挑战接种Pythium aphanidermatum,对黄瓜猝倒病的防治效果达到80.7﹪。说明ND35对这两种植物具有保护作用。利用ND35对番茄幼苗进行根部接种3 d~10 d后,对叶部灰霉病抗性最强,防治效果为22.9﹪~35.6﹪。同时,叶片中与抗性反应有关的酶PAL、POD、PPO活性短期内升高。这表明ND35对番茄幼苗产生了诱导抗病性的作用。更多还原

【Abstract】 The endophytic fungus Chaetomium spirale ND35 was isolated from healthy plants Populus tomentosa. The biological control activities and plant growth-promoting abilities of ND35 on tomato, bean and cucumber were studied in laboratory chamber, greenhouse and field. The investigations of the biocontrol mechanisms of ND35 will provide the theory foundations on exploitation of this new strain in agriculture in the future.The action of strain ND35 was preliminary investigated by the confronting bioassay on PDA plates and light microscopy observation. Strain ND35 exhibited different inhibitory effects on the mycelial growth of four pathogenic fungi , Botrytis cinerea, Alternaria solani, Pythium aphanidermatum and Rhizoctonia solani. The growth inhibition ratio was 54.0﹪, 13.5﹪,55.1﹪and 40.9﹪respectively. Furthermore, stain ND35 showed mycoparasitic phenomena, such as overgrowth in pathogen colonies and coiling around the hyphae of the pathogens.After being inoculated on the seedling roots of cucumber, tomato and bean in greenhouse, the mycelia of strain ND35 could colonize in roots in three days, spread into stems and leaves in seven days in greenhouse. Another experiment also showed the resemble results. The mycelia of strain ND35 could infest into the embryonic roots of cucumber and tomato in forty-eight hours to seventy-two hours under the sterilized conditions. The microscopy observation showed the mycelia expanded into the protoplast after their penetration of cell walls and membranes of the embryonic roots.The strain ND35 could promote the growth of the tomato plants after the colonization in them. The seedling hight, root length, fresh weight of seedling and root had more higher index than the control. After examining some photosynthesis index of the third and the forth leaves of the seedlings pre-treated with strain ND35 and non-treated control in their midanaphase, such as net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO2 concentration(Ci), we found the strain ND35 could enhance photosynthesis performances of the tomato seedlings.The field experiments indicated that strain ND35 could enhance tomato productivities. The quantities of developing flowers, nondeciduous fruits and the single plant productivity of the treated plants were 75.8﹪, 22.7﹪and 14.5﹪higher than the control respectively.In greenhouse, the pot biocontrol experiment showed that strain ND35 had good control effects on bean hypocotyl rot caused by R. solani and cucumber damping-off caused by P. aphanidermatum. Strain ND35 and Rhizoctonia solani were inoculated on the bean seedling roots simultaneously. The disease index decreased from 51.7 to 25.4. The control efficiency was 50.9﹪. The cucumber seedlings which were pre-treated with strain ND35 reduced the disease incidence from 68.9% to 13.3%. Its control efficiency was 80.7﹪.Another pot experiment in greenhouse showed that strain ND35 stimulated the tomato seedlings getting the disease resistance abilities against tomato gray mold caused by Botrytis cinerea. The best control effects on leaves appeared after the inoculation of strain ND35 on the roots from three days to ten days. The control efficiency was 22.9﹪~35.6﹪. Moreover, the enzyme activities in leaves associated with defense response were increased, including PAL, POD and PPO.更多还原