新疆西瓜枯萎病菌营养体亲和性的初步研究

选用１５个采自新疆不同地区的西瓜枯萎病菌株，在含ＫＣｌＯ３培养基上诱导出抗氯酸盐的不能利用硝酸盐营养体突变株（ｎｉｔｍｕｔａｎｔ），在不同氮源培养基上划分出ｎｉｔ１，ｎｉｔ２，ｎｉｔ８，ｎｉｔＭ和ｎｉｔＸ５种突变类型，其中ｎｉｔ１出现频率最高。将各菌株的ｎｉｔ突变株和测试菌株的ｎｉｔＭ或ｎｉｔ８配对，结果１５个菌株分为６个不同的营养体亲和群（ＶＣＧｓ），其中１号小种的菌株划为ＶＣＧ１亲和群，０号小种划为ＶＣＧ２，２株非致病菌株分别为ＶＣＧ３和ＶＣＧ４，２株只出现ｎｉｔＸ突变类型的菌株分别为ＶＣＧ５和ＶＣＧ６。表明营养体亲和群与生理小种存在一致关系，营养体亲和性可以作为西瓜枯萎病菌生理小种鉴定和病原菌种群遗传结构研究的有效手段之一。

Preliminary Study on Vegetative Compatibility of Fusarium oxysporum f.sp. niveum in Xinjiang

Nitrate nonutilizing (nit) mutants were recovered from 15 isolates of F. oxysporumf. sp. niveum by transferring chlorate resistant sectors from KPS medium to MM medium. Furthermore,the five mutant types named nit1,nit3,nit8,nitM and nitX were obtained on different nitrogen media. Nit1 was the most common type.The nitM and nit8 of two known isolates of F.O.f.sp.niveum were selected as the testers to study vegetative compatibility of all isolates. The result showed that all isolates tested were divided into six distinctive vegetative compatibility groups (VCGs).The isolates of Race 1 belonged to VCG1 and Race 0 to VCG2.VCG3 and VCG4 shared the two nonpathogenic isolates, VCG5 and VCG6 represented two nitX mutants.It could be concluded that significant correlation was demonstrated between VCGs and Races in F.O.f.sp.niveum.