Assessment of genetic and biochemical diversity of ecologically variant ectomycorrhizal Russula sp. from India

The aim of this study was to develop the phylogenetic relationship amongst the ecologically variant Russula species by using polymerase chain reaction (PCR) based technique, random amplified polymorphic DNA (RAPD) and isozyme analyses. Two groups could be characterized amongst the total isolates by cluster analyses. Protease, cellulase, glutamate dehydrogenase,  pectinase and acid phosphatase designated band P220.16, C472.18, GLD130.21, Pe569.12 and AP472.12, respectively, were common in all the isolates and four monomorphic RAPD bands viz; 818, 512, 298 and 201 bp were also diversified in the isolates. This common band reveals that diversity of these alleles or loci in all ecologically variant isolates. Thus, the present studies discuss the genetic diversity of ecologically variant Russula species on the basis of RAPD and isozyme analysis

Generation of benomyl resistant Beauveria bassiana strains and their infectivity against Helicoverpa armigera

Beauveria bassiana transformants were obtained by conventional protoplasting and transformed by eletroporation and polyethylene glycol (PEG) treatment. These displayed mitotic stability in Beauveria bassiana. Strains transformed with pSV50 harbouring the beta -tubulin gene of Neurospora crassa grew well on benomyl concentrations of 10 mug ml(-1) unlike the recipient strain. The transformants were mitotically stable on either selective or non-selective medium. The efficiency of transformation by linear and circular pSV50 cosmid was 8 and 10 transformants per mug DNA per ml viable protoplast by electroporation, respectively, and 4 and 6 by the protoplast PEG method, respectively. Southern blot and hybridization of undigested fungal DNA of wild type and four transformants, probed with beta -tubulin sequence of pSV50, showed hybridization at high Mr region of genomic DNA in four transformants, whereas in wild type genomic DNA, no homology of the sequence was observed. Digested genomic DNA, of four transformants gave a complex hybridization pattern. Virulence tests of the transformants showed that there was no significant loss in the pathogenicity toward Helicoverpa armigera third instar larvae. This method of transformation should prove useful with entomopathogenic fungal species in which a genetic transformation system has not yet been established.</p