In vitro Screening of Different Rhizobacterial Strains against Egg Hatching of Rice Root-Knot Nematode, Meloidogyne graminicola

Abstract

Meloidogyne graminicola is an economic yield loss causing major pest of rice globally. For managing this pest, biological control practices act as an alternate strategy, as it is the most effective and economic. Plant growth promoting rhizospheric bacteria (PGPR) are most significant because they benefit plants both directly and indirectly by enhancing plant growth and provides long lasting antagonistic effects against plant parasitic nematodes. Considering this an in vitro efficacy research experiment of nematoxicity of native rhizobacterial strains was conducted, against egg hatching of M. graminicola at S/2 and S/4 concentration levels of intact bacterial culture and cell free culture filtrates (CFCs). The hatching behavior of rice root-knot nematode eggs was observed on alternate days for ten days which resulted in inhibition of egg hatching by all bacterial cultures at both concentration levels. When compared to the untreated control, Bacillus spp. showed the most egg inhibition in the S/2 concentration of both culture filtrates i.e,86.8% and 84.8%. Similarly, in the S/4 level of concentration, most egg hating such as 83.7% and 79.8% was recorded in Bacillus spp. culture filtrates. The rate of hatching was inversely proportional to the concentration of strains at exposure time, decreasing as the concentration increased. The results of the experiment revealed the potential of rhizospheric bacteria which makes it more feasible and environmentally safe approach for the management of Meloidogyne graminicola.