主要环境及营养因素对西瓜枯萎病菌生长的影响

采用菌丝生长速率法和产孢量测定研究了不同温度、光照、pH及碳氮源对来源于海南、河北和上海的3株西瓜枯萎病菌Fo-HN-46、Fo-HB-12和Fo-SH-1生长速率和产孢量的影响。结果表明:西瓜枯萎病菌菌株的适宜生长温度为20~30℃,Fo-HN-46最适生长温度为28℃,Fo-HB-12和Fo-SH-1最适生长温度为25℃,产孢的最适温度为28~30℃;光照对西瓜枯萎病菌生长速率无显著影响,对产孢影响显著,Fo-HN-46在黑暗条件下单位面积产孢量最高,Fo-HB-12和Fo-SH-1在半光照条件下产孢量最高;pH对西瓜枯萎病菌菌株的生长速率和产孢量有显著影响,pH 7~9时菌丝生长速率快,pH 8~11时产孢量高;葡萄糖、淀粉和乳糖作为碳源能够显著增加西瓜枯萎病菌的产孢量;蛋白胨作为氮源能显著促进菌丝生长,硝酸钠、酵母粉和蛋白胨均能显著增加西瓜枯萎病菌的产孢量。用最适碳源、氮源培养,Fo-HN-46生长速率大于Fo-HB-12和Fo-SH-1。Fo-SH-1产孢量高于Fo-HN-46和Fo-HB-12。

Effects of main environmental and nutrient factors on the growth of different Fusarium oxysporum f.sp. niveum strains from watermelon

This study aims to determine the effects of temperature,light,pH value,carbon and nitrogen sources on the mycelial growth and spore production of Fusarium oxysporum f.sp.niveum (FON)from watermelon, which were collected from watermelon production areas of Hainan,Hebei provinces and Shanghai City.The re-sults showed that the suitable temperature for mycelial growth and sporulation were 20-30℃ and 28-30℃,re-spectively.The optimum growth temperature for Fo-HN-46 was 28℃.The optimum growth temperature for Fo-HB-12 and Fo-SH-1 was 25℃.The light had no significant effect on mycelial growth of the pathogen,but had sig-nificant effect on sporulation.The spore yields per unit area of Fo-HN-46 were highest under all darkness condi-tions.The spore yield per unit area of Fo-HB-12 and Fo-SH-1 was highest under alternation of light and darkness conditions.Mycelia growth and spore production of the different FON strains were significantly affected by dif-ferent pH values.The mycelium growth rates of the different strains at pH 7 to 9 were faster than that at any oth-er pH values.The spore yields of the different strains at pH 8 to 11 were faster than that at any other pH values. Glucose,starch,and lactose as carbon source could significantly increase the spore production of F .oxysporum . Peptone as nitrogen sources could promote mycelial growth,while sodium nitrate,yeast extract and peptone could significantly increase the spore yield of the pathogen.There were significant differences in the mycelial growth and spore production among the different F .oxysporum strains when the optimum carbon source or nitrogen source were used.The mycelium growth rate of Fo-HN-46 was faster than those of Fo-HB-12 and Fo-SH-1.The spore yield of Fo-SH-1 was higher than those of the Fo-HN-46 and Fo-HB-12.