Infection Process And The Influence Of Endophytic Chaetomium Globosum ND35 On Host Plant And Its Molecular Detection

The endophytic fungus Chaetomium globosum ND35 was isolated from healthy plants Populus tomentosa. In this study we investigated the infection process and plant growth-promoting abilities of ND35 on plant. The biological control activities of ND35 on poplar were tested in the field. Studies on the biocontrol mechanisms of ND35 will provide the theory foundations on exploitation of this new strain in agriculture in the future.Infection process of C. globosum ND35 in the root of poplar plantlets from tissue culture was observed by means of light microscope, scanning and transmission electron microscope. Hyphae of ND35 attached on the surface of roots and penetrated into the cells of poplar from intercellular space after inoculation for 10 hours. The plant cells wall was penetrated by penetration pegs. At 24 hours after inoculation and later, hyphae of ND35 reached into cortical cells of root. ND35 penetrated into exodermic cells post-inoculation for 48 hours. ND35 infected into a majority of exodermal cells after inoculation for 72 hour. The studies on immunolocation of ND35 with the specific antibodies combine with TRITC or colloid gold surgested samples were only taken from those inoculated plants that allowed the recovery of the fungus in poplar roots cells. ND35 was detected the especially character.Hyphae of ND35 infected and colonized into poplar plantlets from tissue culture produced apparent influences on the pants. The activities of peroxidase, polyphenol oxidase and phenylalanine ammonia lyase significantly increased after inoculation with ND35. The activity of peroxidase and polyphenol oxidase reached the maximum 75.23 U?μg?min-1, 3.098 U?μg?min-1and increased 127.01%, 149.44% after inoculation for 8 days. The activity of phenylalanine ammonia lyase reached the maximum 2.339 U?μg?h-1and increased 241.46% after inoculation for 4 days. The NRA of roots improved markedly after inoculation with ND35. In greenhouse, the activities of roots and the length of roots as well as the contents of chlorophyll were enhanced after inoculation with ND35. The culture filtrate of ND35 was extracted by ethl acetate, concentrated, and the brown crude extracts were obtained. IAA and ergosterol in crude extracts was examined by HPLC. Ergosterol can promote plant growth. So It will provide theory foundations for growth-promoting mechanism.Hyphae of ND35 infected and colonizde into the inside organization of poplars may promot the growth of plant about height growth,the number of radicel and fibres. The experiments in laboratory chamber and in the field indicated that after ND35 colonized into plant can improve resistance to Valsa sordida and the control efficacy is 70% and 90.37%, respectively. That also enhanced the resistance to leaf rust of poplar. In the reisolation experiment ND35 was isolated from the plant tissue such as root, stem and leaf. after 2 months. This indicated that fungus had infected into leaves of plant. The isolation percentage of ND35 reached to 90% in October.ND35 also can promote seeding growth of chestnut. The roots of chestnut seedling compared with poplar were simlar. And the result of reisolation was the same as poplar. Mostly the plant can early abloom after inoculated ND35. The number of anthotaxys were more than control. This will provide theory foundations for growth promoting mechanism.According to the method of CTAB distilled DNA of poplar plantlets from tissue culture and poplar in the field, Separatly with or without ND35. We detected infection and colonization of endophytic Chaetomium globosum ND35 on plant with ITS common primers and specific primers. Result showed that there was clear strip on 100bp. PCR system and specific primers were able to detect colonization of C. globosum ND35. A new method of detection of the fungi was provided.