Rhizosphere and endophytic bacteria for induction of systemic resistance of banana plantlets against bunchy top virus

Bunchy top is one of the most important viral diseases affecting banana production worldwide. Several approaches have been made to control or combat the bunchy top virus disease in banana, transmitted by the banana aphid, Pentalonia nigronervosa Coq. No tactic is able to completely protect the plants against this viral infection. To ameliorate this problem, an attempt was made to use different bacterial strains, which could be inoculated to the roots of micropropagated plantlets to avoid the post transplanting problems. Virus indexed micropropagated plantlets of banana cv. Virupakshi (AAB) were subjected to root colonization followed by foliar spraying with three bacterial strains viz., Pseudomonas fluorescens strains Pf1, CHA0 and Bacillus subtilis strain EPB22 along with an un-inoculated control during primary and secondary hardening stage in the nursery and at the time of transplanting, 3rd, 5th and 7th month after planting in the field. Microbe inoculated plantlets showed improved vegetative growth, physiological attributes, PR—proteins and phenol contents besides reducing banana bunchy top disease (BBTD) incidence in the field. These results indicate that, transplant mixes amended with beneficial bacterial strains can enhance growth of banana plants, besides reducing the damage caused by banana bunchy top virus.