甘薯黑斑病菌的生物学特性研究及室内药剂筛选

Biological Characteristics of Ceratocystis fimbriata and Selection of Fungicides in Laboratory

本试验对甘薯长喙壳菌(Ceratocystis fimbriata Ellis et Halsted)进行了生物学特性研究。结果表明:适宜该病原菌生长的碳源为乳糖,氮源为酵母膏,pH 9,菌落直径分别为4.28,3.96,5.10 cm。菌丝在光照、黑暗、光暗交替下均能生长,其中在黑暗条件下生长最好,菌落直径为5.01 cm,菌丝致死温度为55℃、10 min或58℃、5 min。采用菌丝生长速率法进行了4种杀菌剂对甘薯黑斑病菌的毒力测定。结果表明,供试4种杀菌剂对甘薯黑斑病菌菌丝生长均有抑制作用,其中96.3%苯醚甲环唑抑制作用最佳,EC50值为2.52;其次为97%甲基托布津,EC50值为7.21;97.6%甲基立枯磷和97%氟酰胺抑制作用相对较差,EC50值分别为454.08和425.99。

In this trial, the biological characteristics of Ceratocystis fimbriata Ellis et Halsted which was a fungal disease, was studied. The results showed that the suitable earbonsource for Ceratocystis fimbriata Ellis et Halsted growth was lactose, the suitable nitrogen source was yeast extract, and the suitable pH value was 9. Under these three conditions, the colony diameters of Ceratocystisfunbriata Ellis et Halsted were 4.28, 3.96 and 5.10 cm, respectively. Mycelium could grow in brightness, darkness and alternating light-dark, and the best in darkness. The lethal temperature of myeelium was 55 ℃, 10 min or 58 ℃, 5 min. The toxicity of four fungicides to Ceratocystlsfimbriata Ellis et Halsted was determined by myeelia growth rate method. The result showed that all 4 fungicides inhibited the mycelia growth of Ceratocystis fimbr/ata Ellis et Halsted. Of which the 96.3 % difenoconazole had highest inhibition effect on mycelia growth of Ceratocystisfimbriata Ellis et Halsted, and the value of its ECso was 2.52 ; 97 % Topsin-M fungicides had better, and the value of ECso was 7.21 ; 97.6 % tolclofosmethyl and 97 % Flutolanil had the lowest effect, and the values of EC50 were 454.08 and 425.99, respectively.