Genetic diversity and differentiation of Helicoverpa armigera nuclear polyhedrosis virus isolates from India Charmi Shailesh Patel & Janardan J. Jani & Vipulkumar B. Parekh & Vijay B. Darji & Piyush R. Vaishnav Received: 2 March 2009 / Accepted: 30 September 2009 / Published online: 13 October 2009 # Springer Science + Business Media B.V. 2009 Abstract India has a rich biodiversity of microbes. Soil is the major source for isolation of entomopath- ogens, after the infected insects themselves. Four isolates of Helicoverpa armigera nuclear polyhedro- sis virus (HearNPV) were obtained from the samples collected one each from Anand, Surat and Junagadh of Gujarat and Patancheru of Andhra Pradesh. All the HearNPV isolates appeared as clear, irregular six- sided objects with rounded edges, phase-bright under phase contrast. Junagadh, Surat, Patancheru and Anand isolates gave 27.47–42.80%, 36.83–51.32%, 26.05–43.76% and 42.99–54.85% mortality, respec- tively, when the percent mortality was pooled over period. The least number of HearNPV polyhedral inclusion bodies (PIBs) (5.1×10 7 ) of the Anand isolate were required to kill 50% of the H. armigera population within 120 h. The Anand isolate was fastest (90.30 h), followed by Surat (120.26 h), Junagadh (139.53 h) and Patancheru (143.10 h) in killing 50% of the H. armigera population at a dose of 10 9 PIBs ml -1 . RAPD analysis of all 15 arbitrary oligonucleotide primers generated 353 scorable bands with 201 loci. A total of 181 polymorphic bands were obtained, ranging in size from 141 to 1,873 base pairs. The percentage of polymorphic loci was 90.19%. The mean polymorphism information con- tent (PIC) value for 15 primers was found to be 0.99. The similarity coefficient values based on 15 RAPD markers ranged from 0.235 to 0.407. The four isolates were grouped into two clusters: one cluster consisted of Junagadh and Anand and the second cluster consisted of Surat and Patancheru. Keywords Baculoviruses . Bioefficacy . Genetic diversity . HearNPV . LC 50 . LT 50 . Random Amplified Polymorphic DNA (RAPD) Introduction Baculoviridae is a family of invertebrate viruses with a large, circular and double-stranded DNA genomes ranging in size 81.7 (NeleNPV) to 178.7 kb (XeenGV) (Zhang et al. 2005). They are pathogenic to arthropods, mainly insects of the orders Lepidoptera, Hymenop- tera, and Diptera (Adams and McClintock 1991). Phytoparasitica (2009) 37:407–413 DOI 10.1007/s12600-009-0060-5 C. S. Patel (*) : J. J. Jani Biological Control Research Laboratory, Anand Agricultural University, Anand 388110 Gujarat State, India e-mail: patelcharm17@gmail.com V. B. Parekh Department of Agricultural Botany, B.A. College of Agriculture, Anand Agricultural University, Anand 388110 Gujarat State, India V. B. Darji : P. R. Vaishnav Department of Agricultural Statistics, B.A. College of Agriculture, Anand Agricultural University, Anand 388110 Gujarat State, India