大丽轮枝菌Nit突变体产生及其营养亲和性测定

从DNA限制性酶切多态性(RFLPs)的A组和B组中选用了具代表性的7个大丽轮枝菌菌系作营养亲和性测定.病菌分别接种在含氯酸钾15～25g/l的基本培养基(MM)、梅干培养基(PLA)、玉米粉琼脂培养基(CMA)和马铃薯葡萄糖培养基(PDA)上,从中获得了41个不能还原利用硝酸钠作为唯一氮源正常生长的突变体(Nit).Nit突变体以PDA和PLA含氯酸钾20～25g/l的两种培养基上发生频率较高.根据对不同氮源利用生长情况,获得了Nit突变体5种生理表现型.以Nit1居多(50%～100%),其次为NitM(0～50%).表现型互补的Nit1与NitM突变体营养亲和性测定结果表明,测试菌系可划分为VCG01和VCG02两个营养亲和群,分别含RFLPsA组的4个菌系和B组的3个菌系.

GENERATION OF NITRATE NONUTILIZING MUTANTS AND DETERMINATION OF VEGETATIVE COMPATIBILITY IN VERTICILLIUM DAHLIAE

Seven isolates of Verticillimn dahliae Kleb.obtained from DNA restriction fragement length polymorphisms (RFLPs) were selected for vegetative compatibility tests by using Nit mutants technique.Forty-one Nit mutants were recovered from these isolates of V.dalaliae cultured on minimal medium(MM),prune lactose agar(PLA),cornmeal agar(CMA)and potato dextrose agar (PDA) amended with 15~25g/l potassium chlorate.There were more Nit mutants generated on PDA and PLA media amended with 20~25g/l potassium chlorate.Nit mutants could be divided into five phenotypic classes by their growth on media containing one of five different nitrogen sources:nitrate,nitrite,hypoxanthine,ammonium tartrate and uric acid.The majority of Nit mutams obtained were Nit 1 mutants(50%~100%),much more than Nit M (0~50%).All of these isolates were tested for vegetative compatibility with one another by pairing Nit l and Nit M mutants(1~3cm apart)on minimal medium containing nitrate as a single source of nitrogen.Four isolates obtained from RFLP group A were vegetatively compatible with one another, three from RFLP group B were compatible with one another as well,but isolates from RFLP group A and B were vegetatively imcmpatible with each other.Seven isolates were classified into two vegetative compatibility groups,VCG01 and VCG02,corresponded to the RFLP groups.