The Pathogens Of Stem Canker Diseases Of Prunus Serrulata And Juglans Regia And The Inhibition Effect Of Trichoderma Atroviride

Tree canker is a kind of most serious tree trunk disease in our country. It has a various of pathogens, a wide distribution of host and complex symptoms, it occurs and spreads rapidly and become the focus and difficulty of tree’s disease control. In this article, we choose Prunus serrulata and Juglans regia as the research object, the main research results are as follows:1. Prunus serrulata canker mainly infect stem, The flower and fruit, which infected often fall early and appear dead branches, even the whole tree died, and the ornamental value is affected seriously. This research studies the disease symptom, pathogen morphology culture and physiological characters and the gene sequence character. The results show that the pathogen that causes Prunus serrulata canker is Botryosphaeria dothidea.2. We found there are mainly two kinds of disease symptom on one or two years old walnut branches through the observation. The first kind occurs round or nearly circular light brown ill spots at the early time, and then expanded to dark brown fusiform scab, at last at the central appears longitudinal split. The second kind is shoot dieback. The border is obvious between ill and health because at the edge of disease spot is dark brown and the diseased braches has a little depression, at last, we can find patheogen as small yellow tuber. The flower and fruit, which infected often fall early and the growth and yield of the trees decreased seriously, even the whole tree died. The disease symptom and the identification of the pathogen were studied in this thesis. We get first step conclusion:the pathogen that caused the two kinds of diseases respectly are Botryosphaer dothidea and Phomopsis vaccinii.3. Through isolation and purification, we get a kind of Trichoderma which comes from the diseased branches of Castanea mollissima, it was identified as Trichoderma atroviride after the research of pathogen morphology culture and molecular diversity. The inhibition effect of Trichoderma to the canker pathogens through antagonist experiment, in this experiment we choose Botryosphaer dothide isolated from Prunus serrulata、Juglans regia and Swida alba opiz and Phomopsis vaccinii isolated from Juglans regia. The results shows that the Trichoderma has antibacterial effect to them and can caused the hyphae lysis、withering and breakage. Its antifungal mechanism of Trichoderma is varied, such as competition, dissolve hyphae, antibiotic effect and parasitism.This text identified the diseases of Prunus serrulata and Juglans regia’s branches canker disease, provide theoretical ground for the disease control, at the same time, we studied the inhibition of Trichoerma, so can provide some reference for the application of Trichoderma’s biological control of trees canker disease.