Use of molecular tools to study the diversity of phytopathogenic fungi

The development of the science of Genomics has opened up innumerable possibilities in many areas of scientific research. The time consuming and often laborious process of undertaking a research study is replaced by high throughput techniques of molecular biology. The following review deals in detail about the various techniques carried out for generation of probes to study the diversity of phytopathogenic fungi causing diseases in horticultural crops. An elaborate introduction of molecular markers coupled with PCR and hybridization based detection methods serves to introduce the concept of marker application. A discussion on the amplification and analysis of rRNA, rDNA and spacer region gene clusters is also included. The techniques of rapid amplified polymorphic DNA (RAPD), amplification fragment length polymorphism (AFLP) and PCR-AFLP form the core of the review. The concluding part deals with the target regions in the genome which can be potential candidates for generation of probes. Enterobacterial repetitive intergenic consensus sequences (ERIC), repetitive extragenic palindromes (REP), conserved protein coding genes and microsatellite regions aid in speedy probe generation. The frontline technology of microarray whereby a lot of genes are scanned simultaneously for ‘the genes of interest’ is dealt with at the end of the review. A review of various commonly used procedures for assessing genetic variability of phytopathogenic fungi reveals that molecular tools are indispensable for characterizing and identifying plant pathogenic fungal species and strains, thus their development and application will be of use for all researchers concerned with pathogenic fungal biodiversity, fungal biology and genetics.