利用原生质体再生恢复核盘菌菌株Ep—1PN毒性的研究

分析了６９个随机挑选的核盘菌弱毒菌株Ｅｐ－１ＰＮ原生质体再生后代的生长速度、菌 落形态和毒性。结果表明：其中的３５个再生后代在ＰＤＡ平板上均匀扩展，形成典型的核盘菌菌落，生长速度大于１８ｍｍ／ｄ。在离体莴苣杆上，这些后代的培养物引起较大的病斑。当它们同亲合性菌株Ｅｐ－１ＰＮＡ１８３在ＰＤＡ平板上接触时没有发现Ｅｐ－１ＰＮＡ１８３菌落发生异常变化，说明这些后代已失去了Ｅｐ－１ＰＮ的弱毒因子，恢复了正

STUDIES ON THE RECOVERY OF HYPOVIRULENT STRAIN Ep-1PN OF Sclerotinia sclerotiorum WITH PROTOPLAST REGENERATION

Sixty-nine protoplast-regenerated cultures of Sclerotinia sclerotiorum hypovirulent isolate Ep-1PN were ran-domly obtained from the regeneration medium plates. Their growth rates, colony morphologies and virulence were examined.The results showed that: (1)Thirty-five protoplast-regenerated cultures were thought to be totally recovered because they grew radically on PDA plate and formed typical colony morphologies with normal growth rates (more than 18 mm/d), they could in-duce large lesions on detached lettuce top stems, but could oot cause any detectable effects on the growth of strain Ep-1PNA183, an isogenic and virulent strain of Ep-1PN; (2)Twenty-four protoplast-regenerated cultures were thought to recover to different degrees because they differed in growth rates, colony morphologies and virulence for strain Ep-1PN. They could cause the hyphal tips of strain Ep-1PNA183 to branch excessively when paired with them; (3)Other ten prootoplast-regenerated cultures were not significantly different from strain Ep-1PN.