Biocontrol bacteria and actinomycetes, evaluation of their secondary metabolites against fungal pathogens and insectpest of chickpea

Meesala Sree VidyaMeesala Sree Vidya11 and S Gopalakrishnan and S Gopalakrishnan22

1-Jawaharlal Nehru Technological University, Hyderabad; 2- International Crops Research Institute for the Semi Arid Tropics, Patancheru

*Corresponding author M. Sree Vidya, Email: vidya.meesala@gmail.com

SRICONT

Introduction

•In the present investigation antagonistic and entomopathogenic bacteria and actinomycetes against important fungal pathogens Sclerotium rolfsii, Fusarium oxysporum f. sp ciceri (FOC), Rhizoctonia bataticola (3 strains, RB-6, -24 and -115), Fusarium andiyazi (FM943), Fusarium proliferatum (FM-242), Macrophomina phaseolina (MP) and insectpest of chickpea, Helicoverpa armigera, were studied.

•It is well known that bacteria and actinomycetes found most common in compost and rhizosphere soils. Hence five different herbal vermicompost such as Neem, Annona, Gliricidia, Jatropha, Parthenium and rhizosphere soils from organic fields were selected for isolating the microbes.

•Bacteria and actinomycetes isolated from above sources were characterized for their antagonistic activity against fugal pathogens and insect pests of chickpea. Most potential cultures will be further characterized for in-vitro PGP and biocontrol traits.

Charcoal rot

Dry root rot

Different bacterial isolates inhibiting fungal pathogens.

Objective The main objective of the present investigation is to isolate and identify the active compounds responsible for the inhibition of the fungal pathogens and H. armigera from the potential antagonistic microbes and entomopathogens

Results and Discussion

•Out of 88 actinomycetes isolated, 55, 45, 58 and 37 isolates inhibited MP, Rb-6, Rb-24 and Rb-115 respectively; 33, 36, 13 and 13 isolates inhibited FOC, FM-242, FM-943 and S. rolfsii respectively.

•From 72 bacteria isolated, 28, 25, 29 and 10 isolates inhibited MP, Rb-6, Rb-24 and Rb-115 respectively; 31, 31, 5 and 22 isolates inhibited FOC, FM-242, FM-943 and S. rolfsii respectively.

•The most promising isolates (20) were further evaluated for their PGP and biocontrol traits. The results indicated that xx, xx and xx were shown positive for chitinase, protease, lipase, respectively.

Botrytis gray mold

Materials and methods•Bacteria and actinomycetes were isolated from five herbal vermicomposts and rhizosphere soil from organic field by serial dilution method.•Antagonistic activity of the cultures were evaluated by dual culture assay.•The promising antagonistic cultures were further characterized for their PGP and biochemical traits.

Fusarium wilt

Various fungal diseases of Chickpea

Antogonistic Actinomycetes to Fungal pathogens

01020304050607080

MP Rb-6 Rb-24 Rb-115 Sclerotium FOC FM242 FM943

Fungal Pathogens

No

of Is

olat

es

Antogonistic Bacteria to Fungal pathogens

0

10

20

30

40

50

60

70

MP Rb-6 Rb-24 Rb-115 Sclerotium FOC FM242 FM943

Fungal Pathogens

No

of Iso

late

s

FM-943 Vs SBI-20

FOC Vs SBI-20

Rb-6 Vs SBI-20

S. rolfsii Vs VBI-1

Future workFuture work•Purification of active compound (s) from the culture filtrates. •Physiological characteristics of the promising cultures.•Green house and field evaluation of the promising cultures and their metabolites.

No of actinomycetes isolates antogonistic to different fungal pathogens

No of bacterial isolates antogonistic to different fungal pathogens