Molecular Detection And Field Controlling For The Various Symptoms On Black Stem Of Sunflower

Sunflower black stem is a quarantine disease,which can infect various parts of sunflower.Based on the accurate diagnosis of the disease and the disease investigation of the epidemic control and disease prediction, as well as the disease detection system improvement and effective prevention measures to explore is currently pressing problem.Through the optimization of the amplification system,set up a set of system suitable for the detection of field samples,to adopt different from different parts of sunflower sick symptoms characteristic of the tissue for molecular identification,in order to accurately identify the various symptoms of sunflower black stem.On this basis to carry out multi combination of disease prevention technology research, with a view to the disease prevention and control of the field to screen a combination of efficient and disease prevention.In this experiment,the first to use a pair of specific primers which have been reported for amplification,so as to determine a set of more accurate PCR amplification conditions and systems.The system has strong specificity and high sensitivity,and The specific bands amplified by this system was 425 bp, the best sensitivity of DNA template detection was 0.5 ng/uL.Molecular recognition by different symptoms in a pair of specific primers for the different parts of the field,the results show that:there are 10 kinds of rate of 100% in spite of disease spot respectively Spots between stem,internode black spot and stem Black Brown at base, basal spots, spots of internodes, stem black scattered spots, petiole brown bands, petiole brown, petiole black blight, handle radical black blight,that such disease spot is caused by Phoma macdonaldii Boerma;the rate of 0.0% of the leaves yellow wilt like spot, leaf brown spot two lesion was not caused by Phoma macdonaldii Boerma;Another seven lesion mimic symptoms(internode brown, stem black bands, the stems brown bands, the stems Brown scattered spots, shank ulcer like spots, spots in pulp, sepals black) detection rate was 66.7%, 2 kinds of lesion mimic symptoms(sepals brown spots and stem of longitudinal spot) detection rate was 33.3%, the judgment of the two types of lesion there are still some uncertainty.According to the results of field experiment:it will be highest on the yield(The control effect was 79.63% and 76.85% respectively) and Combination prevention that Seed dressing with 2.5% Fludioxonil FS, then in the middle ten days and last ten-day period of June use two pesticides(Dubangatuo SC 1000 times liquid;Fuxing EW 1000 times liquid) conducted 2 times Stem leaf processing separately.In the demonstration experiment of sowing and flowering variety of stems and leaves in treatment,the best combination of film and ground spraying + 2 times before stem leaves outside the reasonable prevention of diseases, the highest yield.