Dear Kamalesh,

Nitrate non-utilising (Nit) mutants of six field strains and three single-ascospore strains of Botryotinia fuckeliana were selected by plating mycelial plugs onto a nitrate-containing minimal medium amended with chlorate. Mutants were characterised by growth responses on minimal medium amended with various sole nitrogen sources. For each parental strain two mutants were produced: nit1, defective in nitrate reductase apoenzyme; and NitM, defective in the molybdenum cofactor pathway. Complementation on nitrate minimal medium was observed between nit1 and NitM mutants from the same parent in all instances. However, complementation was not observed between any such combinations when the mutants were derived from different parents. It is concluded that a vegetative incompatibility system operates in B. fuckeliana resulting in multiple vegetative compatibility groups. One of the single-ascospore strains was derived from a cross between two of the field strains, indicating that new compatibility groups can be generated during sexual reproduction. Mycelial interaction zones were formed between all parental strains when they were paired on NaCl-amended medium, indicating congruence between mycelial incompatibility and vegetative incompatibility.The use of complementary mutants has been widely used to define VCGs in many filamentous fungi . The results demonstrate that there are at least 18 VCGs in C. actinidiae. It is apparent from table 1 that there is no simple correlation between VCG and host or geographic location. in the targeted samples from the same orchard (B, k) all five strains in both instances were in different VCGs. two strains from the research orchard (a) were in the same VCG (01), but iCMP 7826 was isolated in 1982 whereas iCMP 13962 was isolated in 1999. all other strains in the same VCGs were from different orchards. two of the seven isolates from northland were in VCGs that were also found in the Bay of Plenty (08,12). VCGs have also been investigated in C. curvispora and C. perennans, and some multiple member VCGs were identified but insufficient mutants were recovered to clarify the role of clonality in these species . Although a sexual stage has been recognised for both these species. it is not known whether they are homothallic, and thus nonrecombining, or heterothallic.

Article Vegetative Compatibility and Heterokaryon Formation between ...

Thanks , Prem Baboo Sir.

Dear Kamalesh,

In my opinion the identification of "nit mutants" has no practical sense.

If you have pairs of mutants, tests with one of them and if anastomosis happens is because it belongs to the same group accounting. If not occur anastomosis could be because both fungi have the same mutación.Entonces should try the other if either occurs mutant anastomosis then does not belong to the same group. No matter have identified the members of the pair.

best regards

Pedro

Thanks sir