Biological Characteristics Of Ustilaginoidea Virens (Cke) Tak And Fungicides Screening

Five Ustilaginaoidea viren strains are isolated from Feidong(FD),Quanjiao(QJ), Qianshan(QS),Lujiang(LJ)and Xuancheng(XC)in Anhui,respectively.The biological characteristics of U.virens range is 5℃to 35℃,but the hypha growth is 28℃,lower than 5℃is can not growth and higher than 35℃is sub-pressed growth.Between the hypha growth and the temperature satisfies the conic section model,the correlation coefficient respectively is 0.9596,0.9728,0.9674,0.9283,0.9595.The conidia producing and the conidia germination are existence difference,among the 5 different strains of U.virens, except strains XC cannot producing conidia,other 4 strains can produce conidia in the liquid media.But respective produces the conidia quantity is existence difference,in which stain FD produces the conidia ability to be strongest,and produces the conidia quantity in 10⁵-10⁷/ml.The medium PS produces the conidia quantity to be strongest in 3 kinds of media,is obviously higher than coercion this wise liquid and the potato-malt sugar fluid media.The conidia germination optimum and lowest temperature is 28℃and 15℃respectively in different strains.When the temperature is higher than 37℃,the conidia cannot germination normally,its lethal temperature is 56℃.In 16℃-300℃,the conidia germination rate and the temperature satisfies the logical model of 4 strains QJ,QS,FD, and LJ.The decision coefficients is 0.9892,0.9921,0.9927,0.9824 respectively.U.virens grows the most suitable pH value is between 6-7,pH value satisfy 3 multinomial relations, 5 strain correlation coefficients respectively is 0.9574,0.9567,0.9600,0.9386,0.9685. Conidia germination in 4 stains is sensitive to the pH value,the most suitable pH value between 6-7,between conidia germination rate and the pH value satisfies 3 multinomial models,its correlation coefficient is 1.0000,0.9928,0.9826,0.9990.Most suitable carbon and nitrogen source of U.virens are the sucrose and L-asparagus gate amide respectively, its most suitable concentration are 2%and 0.2%-0.3%,respectively.Relationship between the hypha growth and carbon and nitrogen sources are tested,the results show that different concentrains of carbon and nitrogen source are satisfied the conic section and three multinomial models separately.Through bioassay in lab,the results indicate that the U.virens is sensitive to all testing fungicides.Providing trial 9 fungicides to U.virens,toxicity determination the results show that Diniconazole is highest toxicity,its EC50=0.14μg/ml.Propiconazole EC50=0.26μg/ml, Prochloraz EC₅₀=0.30μg/ml,Myclobutanil EC₅₀=0.31μg/ml,Sodium pimaric acid EC₅₀=0.57μg/ml;Carbendazim EC₅₀=0.89μg/ml;Tebuconazole EC₅₀=0.89μg/ml, Benomyl EC₅₀=1.13μg/ml;Jinggangmeisu EC₅₀=13.6μg/ml.Its correlation coefficient R² is 0.9265,0.9175,0.9187,0.8519,0.9342,0.9093,0.9643,0.8242,0.8911,respectively.Further carries on duplicate matches the formula screening,altogether obtains 10 to have the obvious efficiency combination 12 efficiency formula.In which has 8 formula coordination coefficient SR to be bigger than 2.0,the performance strong efficiency function,i.e.,the Diniconazole and Propiconazole(B),SR=2.15,Dniconazole and Prochloraz(B,A),the SR is 3.70,2.08,respectively;Diniconazole and Jinggangmeisu(E), SR=2.30;Prochloraz and Jinggangmeisu(E),SR=2.23;Myclobutanil and Prochloraz (B),the SR=2.12;Prochloraz and Propiconazole(D),the SR=2.10.There are 5 formulas that the actual EC₅₀are less than 0.5μg/ml,that is respectively is Diniconazole and Prochloraz(B),EC50=0.06μg/ml,Diniconazole and Jinggangmeisu(E),EC₅₀=0.10μg/ml; Diniconazole and Prochloraz(A),EC₅₀=0.12μg/ml;Diniconazole and Propiconazole(B), EC₅₀=0.048μg/ml;Prochloraz and Propiconazole(D),EC₅₀=0.048μg/ml.