Research On Disease Occurrence And Distribution, Molecular Detection And Control Measures Of Sunflower Black Stem

The sunflower black stem,found in the Ili river valley, Xinjiang, China, is a domestic new disease. The black stem of sunflower has been added to the quarantine pests list of China in2010by department of agriculture. Since the disease occurred in xinjiang, it became epide-mic and spread in main planting area of Yili, Xinjiang, and made sunflower industry of Xinji-ang facing a serious threat. So it is a urgent task to understand and manage this disease. The relevant research of pathogen(Phoma macdonaldii) has been carried out in nutrient condition, temperature gradient and acid-base adaptability. Molecular identification and molecular detec-tion technology, and screened high efficiency, safety, friendly fungicide by drug experiments indoor and outdoor.Pathogen was confirmed by rDNA-ITS Sequences analysis, sequencing, and blast. The occurence of sunflower black stem was validate from molecular level.The results shown that pathogen of sunflower black stem belongs to non-obligate parasit-es and has a wide range of environmental adaptability, in nutrient condition, temperature and acid-base adaptability. Acidic conditions is conductive the growth of pathogen. Pathogen can infected all the air parts of plant during whole growing period under natural conditions. The high humidity and injury is conductive to infection and morbidity, under artificial inoculation conditions.Molecular markers techniques is established through the specific primer design and scre-ening; molecular detection technology of field strains is established by the molecular marker and sencitivity detection of specific primers, and experimental verification.The distribution of sunflower black stem was cleared by the investigation of disease dist-ribution, Yili regions and Changji city were main distribution area of sunflower black stem. GARP genetic algorithm model, combined with Xinjiang’s geography and climate characteris-tics, and GIS software have been used to analyze the potential suitable of sunflower Phoma b-lack stem in Xinjiang; The possibility of the risk degree of Phoma black stem in various re-gions of Xinjiang has been assessed by multi-index comprehensive evaluation method. The assessment results show that the degree of risk were more higher in north of Xinjiang, the Tianshan area was mainly distributed, the region was between latitude43～50degrees.The comparition results of varieties resistance shown that28varieties of sunflower exit-ed differentially, but many of them is susceptible. Five more resistance varieties re screened, they are TO12244, S606, Xinkui hybirds7, Q1026, and LD1003.The results shown that the Yimeijing (30%WP), flusilazole (10%EW), tebuconazole (25%SC) and myclobutanil azole (12.5%EC) had significantly inhibited to the pathogen in toxicity test of different fungicides; and flusilazole (1000x) was significantly superior to other types of processings. Outdoor test confirmed that flusilazole (10%EW) and Yimeijing (30%WP) on the disease control were more higher in control efficiency.