Influence of mineral amendment on disease suppressive activity of Pseudomonas fluorescens to Fusarium wilt of chickpea.
Fusarium wilt caused by Fusarium oxysporum f. sp. ciceri causes considerable yield loss of chickpea. Pseudomonas fluorescens4-92 (Pf4-92) strain can suppress the disease. Amendment of zinc EDTA and copper EDTA could not suppress the disease significantly when used alone; however, they significantly suppressed the disease in presence of Pf4-92. In vitro observation showed that at 40, 30 and 20microgml(-1) concentrations of these minerals, i.e. Zn, Cu and Zn plus Cu, respectively, completely repressed the production of the phytotoxin, fusaric acid (FA). FA concentration (0.5microgml(-1)) has been shown to suppress the production of 2,4-diacetylphloroglucinol (DAPG) by Pf4-92, and DAPG, salicylic acid, pyochelin and pyoluteorin production was enhanced by these mineral amendments. In rockwool bioassays, Zn, Cu and Zn plus Cu amendments reduced FA production and enhanced DAPG production. This study demonstrates that Zn and Cu enhance biocontrol activity by reducing FA produced by the pathogen, F. oxysporum f. sp. ciceri.
Saikia
Ratul
R
National Bureau of Agriculturally Important Microorganisms (NBAIM), Kushmaur, Mau 275 101, Uttar Pradesh, India. ratulsaikia@yahoo.com
Varghese
Saju
S
Singh
Bhim Pratap
BP
Arora
Dilip K
DK
D000898:Antibiosis / Q000187:drug effects*; D029863:Cicer / Q000254:growth & development / Q000382:microbiology*; D003300:Copper / Q000494:pharmacology; D005669:Fusaric Acid / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D005670:Fusarium / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity; D008903:Minerals / Q000494:pharmacology*; D010636:Phenols / Q000378:metabolism; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D011758:Pyrroles / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D015032:Zinc / Q000494:pharmacology
D008903:Minerals; D010636:Phenols; D011758:Pyrroles; D013844:Thiazoles; C095503:pyoluteorin; C025316:pyochelin; D003300:Copper; C059817:2,4-diacetylphloroglucinol; D010696:Phloroglucinol; D015032:Zinc; D005669:Fusaric Acid; D020156:Salicylic Acid