Antagonistic Activity of Plant Growth Promoting Fluorescent Pseudomonas Spp. against Major Fungal Pathogens Involved in Replant Problem of Apple

Neha Kaushal, Mohinder Kaur
2020 International Journal of Current Microbiology and Applied Sciences  
Replant disease is a major problem of apple orchards, which is a main cash crop in Trans-Himalayan region. The cause of this replant problem includes both biotic and abiotic factors, such as low nutrients, phytotoxins, actinomycetes, fungal complexes and nematodes. Fungi and oomycetes belonging to the well-known root rot complex are important factor of replant problems in apple. Application of plant growth promoting fluorescent Pseudomonas with antagonistic potential at replant site is one of
more » ... e promising methods being a major component of rhizobacteria, promotes the plant growth and also act as biocontrol agents against fungal plant pathogens. In the present study, 14 fluorescent Pseudomonas isolates were screened out for in-vitro antagonistic activity by well plate assay method against five major fungal pathogens of apple replant problem viz., Dematophora necatrics, Phytophthora cactorum, Pythium ultimum, Fusarium oxysporum and Rhizoctonia solani. Out of these 14 fluorescent Pseudomonas isolates, maximum % inhibition was shown by Pseudomonas strain K (48.38 %) against D. necatrics, An-5-Jub (34.09 %) against F. oxysporum, isolate I (31.57 %) against P. cactorum, Ps-1-Sin (35 %) against P. ultimum and isolate J (28 %) against R. solani. These fluorescent Pseudomonas isolates with strong antagonistic potential against different fungal pathogens of replant problem not only reduce the replant problem by suppressing pathogens and improving plant growth through multifarious plant growth promoting activities but also helps in the maintenance of soil health by reducing indiscriminate use of chemicals and therefore can be helpful in solving the replant problem of apple.
doi:10.20546/ijcmas.2020.904.273 fatcat:vwyhjmmd5nbs5kwb5f3uuspkpe