论文部分内容阅读
从４个不同专化型的７个尖孢镰孢菌株上共诱得１２６个不能利用硝酸盐的营养突变株（ｎｉｔｍｕｔａｎｔ）。经表型测定，它们分别属于５种不同的基因突变类型，其中一种不能利用尿酸的突变类型，是在尖孢镰孢中首次发现的，暂定名为ｎｉｔＸ。不同菌株在ＫＰＳ培养基上产生各突变类型的比例有差异，测定各菌株的自身营养体亲和性（不包括ｎｉｔＸ）。结果显示，除一个异核自身不亲和的菌株外，（１）不同突变类型间亲和力差异较大，其中ｎｉｔＭ与各突变类型均有较高亲和力，尤其证明ｎｉｔＭ与ｎｉｔ８或ｎｉｔ３的亲和指数达１００；（２）就各具体的ｎｉｔ突变株的亲和指数看，所有菌株的各ｎｉｔＭ突变株的亲和指数达５０～９４，营养体亲和力高，而且很稳定，另有一些ｎｉｔ８突变株的亲和指数也在５０以上。选用已知专化型的标准菌株的ｎｉｔＭ作为测定未知菌株专化型的标准突变株较为可靠，若标准菌株不易产生ｎｉｔＭ，也可考虑选择亲和指数高的ｎｉｔ８作为标准突变株。确定二菌株间亲和性配对试验的最少配对次数时，除标准突变株的亲和指数外，被测菌株所能产生的各突变类型的比例和各突变类型间亲和指数的差异也会在一定程度上影响亲和试验结果，而选用被测菌株的ｎｉｔ８或ｎｉｔ３突变株?
126 nitrate mutants (nitmutants) were induced from seven Fusarium oxysporum strains from four different specializations. Phenotypically determined, they belong to five different types of gene mutations, one of which can not take advantage of the type of mutation in uric acid, Fusarium oxysporum was first found tentatively named nitX. Different strains have different proportions of each mutant type on KPS medium, and the self-vegetative affinities (excluding nitX) of each strain are determined. The results showed that in addition to a heteronuclear non-affinity strains, (1) different types of mutations between the different affinity, which nitM with higher affinity for each mutation type, in particular, that nitM and nit8 or nit3 affinity index Up to 100; (2) For each specific nit mutant, the affinity index of all the nitM mutants reached 50-94, the vegetative affinity was high and stable, and some nit8 mutants The affinity index is also above 50. It is more reliable to select nitM as a standard mutant strain for the determination of unknown strains. If the standard strain is not easy to produce nitM, nitM as a standard mutant strain with high affinity index can also be considered. When determining the minimum number of pairs of affinity pairing tests between two strains, the ratio of each type of mutation that can be produced by the tested strains and the affinity index between each mutation type, except the affinity index of the standard mutant strain, To a certain extent affect the affinity test results, and use the test strains nit8 or nit3 mutant?