Intraspecific variability in Phomopsis azadirachtae infecting neem

Abstract

Phomopsis azadirachtae Sateesh, Bhat and Devaki is the causal agent of die-back disease of neem. Six isolates of P. azadirachtae collected from different geographical regions of Tamilnadu were subjected to SDS-PAGE to study the variation among the isolates. Mycelial soluble proteins extracted from the six isolates exhibited marked variations in their electrophoretic protein profile. A few bands were common to all the isolates and each isolate also had a few specific bands. Soluble proteins were resolved into 42 bands of different molecular weights. Similarity index obtained ranged from 29.63% to 59.26%. Above findings indicate the existence of variability in P. azadirachtae isolates and its heterogeneous nature, revealing the genetic diversity of the pathogen.

Keywords:

• Die-back
• neem
• Phomopsis azadirachtae
• variations
• mycelial soluble proteins
• protein profile

Acknowledgements

The authors wish to thank the University of Mysore for its facilities. K. Girish, acknowledges DST, New Delhi for financial support.