The present work is an attempt to develop transgenic hairy root system in Camellia assamica, using leaves infected by Agrobacterium rhizogenes strain LBA9402, harboring binary vector (pART27 and pBI121) carrying β-glucuronidase (gus) as reporter gene and neomycin phosphotransferase (nptII) as selection marker. The transformed hairy roots were grown in phytohormone free MS media in the presence of kanamycin 50 µg/ml. The incorporation and expression of foreign genes were checked by initial gus assay followed by PCR analysis for the presence of nptII and β-glucuronidase (gus) gene. This protocol therefore facilitates the study of gene expression system in general and for root functional genomics in particular, giving scope for transgenic hairy roots as future explants for secondary metabolite production and plantlet regeneration.

Hyposidra talaca is a major defoliating pest of tea plants in north-eastern part of India. In this study, we look for variations (if any) in the attacking virus. Viral samples were collected from different regions of the northern part of West Bengal in India and were analyzed by PCR technique to study the variations across the region. The partial segment of the HytaNPV polyhedrin gene was cloned and sequenced. A 527 bp nucleotide sequence containing highly conserved region from polyhedrin gene of HytaNPV was observed. The blast homology search for studied polyhedrin gene showed 98% sequence identity with the sequence of previous reported NPV of H. talaca, H. infixaria and Buzura suppressaria. Pathogenicity study against second instar H. talaca indicated that the LC50 values ranged from 4.61 × 105 to 7.57 × 105 polyhedral occlusion bodies per ml (POBs/ml) and the LT50 values ranged from 4.2 to 6.66 days. Sequencing result reveals that the same HytaNPV strain dominates across this area and the pathogenicity indicates its potential as an alternative to chemical insecticides to control H. talaca.