Isolation and characterization of secondary metabolites of actinomycetes against plant pathogens of chickpea and

sorghum

*Corresponding author G.Alekhya, Email: alekhya.chinnu@gmail.com

SRICONT

Actinomycetes cultures showing inhibition

INTRODUCTIONActinomycetes are known to have plant growth promoting traits and antagonistic activity against plant pathogens. The objective of the present experiment is to isolate the promising strains of actinomycetes against pathogenic fungi and to isolate the metabolites responsible for it. The fungal pathogens studied include Sclerotium rolfsii, Rhizoctonia bataticola (three strains viz. RB-6, -24 and -115) Fusarium oxysporum f. sp. ciceri, Botrytis cinerea, and Macrophomina phaseolina causes collar rot, dry root rot, Fusarium wilt, Botrytis grey mould diseases in chick pea and charcoal rot in sorghum, respectively.

CONCLUSION

A total of 45 actinomycetes were isolated from SRI fields Among 45 actinomycete isolates screened 16 isolates showed broad spectrum anti fungal activity.In the culture filtrate assay, six actinomycetes showed broad spectrum inhibition at 10% filtrate.

The potential antagonistic actinomycetes showed PGPR traits which includes chitinase activity, HCN production, lipase activity, protease activity, cellulase, IAA production and Siderophore activity.

The duel plate assay and culture filtrate bioassay results showed difference which should be further studied, as some of the cultures showing good results in DPA failed to inhibit in the form of culture filterates.

Further the metabolites of the positive cultures should be studied to isolate the most promising compound.

The amount of chemical fungicide used against fungal pathogen should be reduced by supplementing with positive actinomycetes cultures

*Gottumukkala Alekhya and S. *Gottumukkala Alekhya and S. GopalakrishnanGopalakrishnan

Actinomycetes cultures showing inhibition

METHODOLOGY

•Isolation of actinomycetes from ICRISAT SRI rice field •Antagonistic activity of actinomycetes against plant pathogens were tested by Duel Culture Assay •Effect of the culture filtrates of actinomycetes on fungal pathogens were done •The PGPR traits of the antagonistic actinomycetes were studied by using different selective media.•The physiological and morphological properties of the potential actinomycetes were studied.

Antagonistic activity of culture filtrates against fungal pathogens

Duel plate assay

Botrytis grey mould

Fungal diseases of chickpea and sorghum

Dry root rot Charcoal rot Fusarium wilt Collar rot

BCA667 BCA698 CAI 8 CONTROL0

10

20

30

40

50

60

70

80

90

100

MP

RB6

RB24

RB115

FOC

FM242

FM943

SCL

BCA 667 CAI 8 BCA 696 CAI 1330

2

4

6

8

10

12

14

16

18

MP

RB6

RB24

RB115

FOC

FM242

FM943

SCLEROTIUM

BOTRYTIA

BCA 696 Inhibiting RB6 BCA 696 inhibiting FOC

BCA 696 inhibiting Rb115 CAI 133 inhibiting Fm 242

BCA 667 inhibiting different fungal pathogens

FUTURE WORKTests have to be done to reduce the amount of chemical fungicide used normally by supplementing with positive actinomycetes cultures.

Isolation and purification of metabolites of actinomycetes and to check their antagonistic activity against plant pathogens