苜蓿假盘菌的生物学特性研究

摘要：本试验研究了温度、水分、pH值、光照、碳源、氮源以及无机盐对苜蓿假盘菌(Pseudopeziza medicaginis)宁夏菌株生物学特性的影响。结果表明，苜蓿假盘菌宁夏菌株在5～30 ℃、pH值4.0～10.0均可生长，最适温度为20～25 ℃，最适pH值为5.0～6.5，该菌随光照强度的增加生长受到抑制，能利用固体培养基上不同的碳源，对葡萄糖和麦芽糖的利用较好。除尿素抑制病菌的生长外，该菌能不同程度利用无机氮源和有机氮源，菌落直径和生长速率基本一致，差异不明显，但菌落数差别较大，无机氮源优于有机氮源。供试的4种盐溶液除KH2PO4没有菌生长外，其余3种生长量基本一致，但4种盐溶液下生长的菌落均不产生子囊盘。叶片表面的游离水及游离水保持的时间可影响孢子的萌发，且叶表游离水保持3 h以上，孢子才能萌发。

The biological characteristics of Pseudopeziza medicaginis in alfalfa

An experiment was conducted to determine the effect of temperature,humidity,pH,light,carbon sources,nitrogen sources and inorganic salts on pathogenic biological characteristics of Pseudopeziza medicaginis in alfalfa Ningxia strains.This study showed that P.medicaginis of Ningxia strains grew well at the temperature ranging from 5 ℃ to 30 ℃ and the pH value ranging from 4.0 to 10.0,and the optimal temperature and pH value was 20~25 ℃ and 5.0~6.5,respectively.The growth of this fungus was inhibited by the increasing light intensity and it had ability to utilizing different carbon sources on solid medium,especially glucose and maltose.This fungus could use inorganic nitrogen and organic nitrogen source to some extent except for urea,indicating that colonies’ diameter and growth rate were in accord,but the number of colonies in inorganic nitrogen source was better used than that in organic nitrogen sources.The fungus in three kinds of saline solution shared in increasing common except for KH2PO4,however,apothecium was not observed in 4 saline solutions.Free water on leaf and its maintenance period directly influenced the germination of spore,indicating that the spores germinated when free water on leaf was over 3 hours.