The Effects Of Numerically Dominant Endophyte Colletotrichum On The Growth And Enemy Release Of Eupatorium Adenophorum

Invasive species can alter the biological diversity, composition, structure, and function of terrestrial ecosystem.The crofton weed(Eupatorium adenophorum Spreng) is one of the worst invasive weeds in the world, and it has caused great economic losses and environmental problems. It is an urgency to find some methods to control the spread of crofton weed.But at first, it is necessary to know the invasive methanism of crofton weed.Fungal endophyte is a kind of symbiotic fungi colonizing inside plant stem and leaves.Some reseach shows, the endophyte in plant could cause physiochemical changes, which may kill the herbivores or induce resistance of the host plant to biotic or abiotic stresses. The plant rhizosphere secretions also can be affected by this plant endophyte, and then it can impact the relationship between host plant and soil microbes. The crofton weed may have the similar relationship with its endophyte,that has positive feed back on invisibility of crofton weed.This paper based on ERH (enemy release hypothesis), the endophytic infection leaves of crofton weed was challenged by the pathogen(Diaporthe helianthi), the insect (Prodenia litura) and the soil microbes, our reseaches suggested some results as follows:1. The endophyte(Colletotrichum) and pathogen(Diaporthe helianthi) interacted with each other, but there was no significant results to show endophyte can induce host resistance to pathogen.2. There were natural enemies of crofton weed in farmland soil, but no or just a few of natural enemies in forest soil.3. The endophyte can reduce the damage of crofton weed leaves by insect,but multiple species of endophytes can make more significant influence compared with single endophyte.4. The endophyte affected negtively the growth of crofton weed, but at the same time,it played a certain role in helping crofton weed to resist enemy.