Biological control of Fusarium oxysporum f.sp. radicis-cucumerinum, the casual agent of root and stem rot of Cucumis sativus by non-pathogenic Fusarium oxysporum

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

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Biological Control of Fusarium Wilt in Tomato Caused by Fusarium oxysporum f. sp. lycopersici by AMF Glomus intraradices and some Rhizobacteria

Journal of Phytopathology ◽

10.1111/j.1439-0434.2005.01018.x ◽

2005 ◽

Vol 153 (9) ◽

pp. 544-550 ◽

Cited By ~ 71

Author(s):

A. Akkopru ◽

S. Demir

Keyword(s):

Biological Control ◽

Fusarium Oxysporum ◽

Fusarium Wilt ◽

Glomus Intraradices

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Characterization of Fusarium oxysporum Isolates Obtained from Cucumber in China by Pathogenicity, VCG, and RAPD

Plant Disease ◽

10.1094/pdis.2004.88.6.645 ◽

2004 ◽

Vol 88 (6) ◽

pp. 645-649 ◽

Cited By ~ 45

Author(s):

D. J. Vakalounakis ◽

Z. Wang ◽

G. A. Fragkiadakis ◽

G. N. Skaracis ◽

D.-B. Li

Keyword(s):

Fusarium Oxysporum ◽

Random Amplified Polymorphic Dna ◽

Vegetative Compatibility ◽

Stem Rot ◽

Chinese Isolate ◽

Vegetative Compatibility Group ◽

Group I ◽

Compatibility Group ◽

First Time

Thirty-four isolates of Fusarium oxysporum, obtained in China from cucumber plants showing either Fusarium wilt (F. oxysporum f. sp. cucumerinum) or root and stem rot (F. oxysporum f. sp. radicis-cucumerinum) symptoms, were characterized by pathogenicity, vegetative compatibility, and random amplified polymorphic DNA (RAPD). Of these, 23 isolates were identified by pathogenicity as F. oxysporum f. sp. cucumerinum, and one as F. oxysporum f. sp. radicis-cucumerinum, while 10 isolates were avirulent on cucumber, melon, sponge gourd, and pumpkin. The Chinese isolates of F. oxysporum f. sp. cucumerinum were assigned to RAPD groups III and XXI and to vegetative compatibility group (VCG) 0183, four new VCGs, 0184 to 0187, and a single-member VCG included in the artificial VCG 018-. The Chinese isolate of F. oxysporum f. sp. radicis-cucumerinum was assigned to RAPD group I and bridging VCG 0260/0261. The occurrence of F. oxysporum f. sp. radicis-cucumerinum on cucumber is reported for the first time in China.

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