杨梅凋萎病菌异色拟盘多毛孢菌(Pestalotiopsis versicolor)的生物学特性研究（英文）

Biological characteristics of Pestalotiopsis versicolor,the agent of bayberry twig blight in Southern China

为了明确杨梅凋萎病的病原菌之一异色拟盘多毛孢菌（ Pestalotiopsis versicolor）的生物学特性，对其3个代表菌株XJ27、XJ42、RA2-1在不同培养基、碳源、氮源、温度、pH、光照条件下的生长以及产孢情况进行研究。研究结果表明，在7种培养基上25℃培养时，PDA和PSA最适合菌株气生菌丝生长，菌丝生长速度快而茂盛。杨梅汁（BFA）上菌丝生长较快，但是不茂盛。燕麦培养基（OMA）和查氏培养基（CDA）中等适合，杨梅叶煎汁（ BLA）和杨梅枝干煎汁（ BBA）不适合气生菌丝生长。10种不同碳源培养基以及硝酸钾、硝酸铵、尿素和8种测定的氨基酸作氮源的培养基上3个菌株都生长良好，但是木糖培养基上生长较差。菌株在25～28℃能很好地生长，20℃和30℃生长中等，但是在5℃和35℃不能生长。 pH 5～10菌丝生长较好，但是pH 11.0菌丝不能很好生长。光照条件下，XJ27和XJ42生长后10天，有光照的产孢量大大多于没有光照的，但是RA2-1产孢不受光照影响。总之，杨梅凋萎病菌异色拟盘多毛孢菌具有广泛的培养基、碳源、氮源、温度以及pH的适应性，光照对部分菌株产孢性能有促进作用。

To study the biological characters of Pestalotiopsis versicolor, one of the agents of bayberry twig blight dis-ease, the effects of media type, carbon （C） and nitrogen （N） sources, temperature, pH, and light on P.versicolor were examined to determine optimal conditions for mycelial growth and sporulation .Three independent isolates showed a similar trend of growth and sporulation with different C and N sources .However , the growth rates varied significantly among seven agar media .Fungal growth rates were the highest on potato dextrose agar （ PDA） and pota-to sucrose agar （PSA）.The fungi grew fast on bayberry fruit extract agar （BFA） but sparsely.Growth rates were moderate on oatmeal agar （ OMA） and Czapek-Dox agar （ CDA） , and low on bayberry leaf extract agar （ BLA） and bayberry branch extract agar （BBA）.Sucrose, dextrose, maltose, lactose, mannose, levulose, sorbose, and starch were optimal carbon sources , whereas glycerol and ribose were moderate , and xylose was poor for the fungus .Potas-sium nitrate, ammonium nitrate, urea, and all of the amino acids tested （ i.e.cysteine, glycine, tyrosine, histi-dine, alanine, arginine, glutamate, and proline）, were good sources of nitrogen for the fungus .Growth occurred be-tween 10 and 30℃and was optimal between 25 and 28℃.Growth was normal and no significant difference between pH 5 to 10 was found .The quantity of conidia from two isolates （ XJ27 and XJ42 ） on PDA after 10 days growth un-der light was significantly greater （P〈0.001） than that under darkness .In contrast, sporulation of the other iso-late, RA2-1, was unaffected by light .P.versicolor has wide adaptivity to media , carbon, nitrogen, temperature and pH, while light influences sporulation of some isolates .These results will be helpful to understand the epidemiology of the disease and to develop a reasonable disease management strategy in reforestation areas .