MOLECULAR CHARACTERIZATION OF Ceratocystis manginecans sp. FROM MANGO IN PAKISTAN

A serious mango sudden death caused by Ceratocystis sp. is an important disease of Pakistan. Symptoms of affected trees include bark splitting, discoloration of the vascular tissue, wilting, gummosis and eventually results in rapid death. Detailed molecular analysis is performed based on nuclear ribosomal DNA Ceratocystis sp. Sequencing of nuclear encoded ITS1-5.8 s –ITS2 rDNA region confirmed preceding taxonomic conclusion based on morphology. Evolutionary reconstructions consequences in a phylogenetic tree of internal transcribed spacer. Blast searches showed that isolates from Pakistan grouped within the C. fimbriata species complex and were most closely related to C. manginecans. Three clades were observed that included Ceratocystis sp. with similar morphological features. Unexpectedly sequence analysis revealed genetic variations distinguishing the Ceratocystis manginecans from Ceratocystis fimbriata. The identified genetic variation in Ceratocystis species appears to affect the 5.8s RNA folding as deduced from secondary structure models. It is revealed that Ceratocystis manginecans internal transcribed spacer ITS and ITS2 folds into the multi branched closed and open loop with different locations in different species of Ceratocystis.