scholarly journals Fungal leaf spot diseases of mango (Mangifera indica L.) in Southeastern Nigeria and biological control with Bacillus subtilis

2011 ◽  
Vol 39 (No. 2) ◽  
pp. 70-77 ◽  
Author(s):  
R.N. Okigbo ◽  
M.I. Osuinde
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Leaf Spot ◽  
Control Method ◽  
Control Measure ◽  
Mangifera Indica ◽  
Pathogenic Fungi ◽  
Southeastern Nigeria ◽  
Plant Materials

The incidence of fungal leaf spot diseases on mango (Mangifera indica) in Southeastern Nigeria and application of a biological control measure was investigated. The survey proved that the incidence of leaf spot diseases was greatest in Umuahia (72%) followed by Okigwe and Ojoto, with a peak at the beginning of the rainy season (February–March). Three pathogenic fungi, Pestalotiopsis mangiferae, Botryodiplodia theobromae and Macrophoma mangiferae, were isolated from leaf spots. Other fungi, Fusariella spp., which are well known saprophytes of dead plant materials, and the fungus Meliola sp., were also isolated from diseased leaves. Pathogenicity tests showed that P. mangiferae, B. theobromae and M. mangiferae were the causal agents of the fungal leaf spot diseases. Symptoms developed 5 weeks after inoculation of healthy leaves. Bacillus subtilis NCIB 3610, isolated from soil under a mango tree, inhibited P. mangiferae, B. theobromae and M. mangiferae by 57%, 61% and 58% respectively on agar plates. Also, in in vivo experiments the symptoms were considerably reduced in the field by the application of the antagonist. The importance of the biological control method for rural mango farmers is emphasised.  

scholarly journals BIOLOGICAL CONTROL OF Colletotrichum gloeosporioides IN PEPPER WITH ISOLATES OF Bacillus subtilis

2018 ◽  
Vol 93 (2) ◽  
pp. 195
Author(s):  
Jeniffer Kelly Cortes Amaro ◽  
Bruno Sérgio Vieira ◽  
Luciana Alves Sousa
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Colletotrichum Gloeosporioides

Objetivou-se estudar o potencial antagônico de isolados de Bacillus subtilis a Colletotrichum gloeosporioides, agente causal da antracnose em frutos de pimenta. Foram estudados 21 isolados de Bacillus subtilis quanto a capacidade de inibir o desenvolvimento do fitopatógeno nas seguintes metodologias in vitro: cultivo pareado, metabólitos produzidos pelos isolados, influência da inoculação conjunta e controle da antracnose in vivo (frutos destacados de pimenta). Os isolados BSV-11, BSV-05, BSV-12, BSV-17, BSV-07, BSV-16, BSV-09, BSV-20, BSV-13 e BSV-18 foram promissores como potenciais antagonistas a C. gloeosporioides, com evidente formação de halo de inibição, para a metodologia do cultivo pareado. Estes isolados produziram metabólitos termoestáveis contra C. gloeosporioides evidenciando ser antibiose o mecanismo antagônico envolvido na supressão do patógeno. O contato direto dos isolados bacterianos com o patógeno inibiu totalmente o crescimento micelial de C. gloeosporioides, exceto os isolados BSV-20 e BSV-09. Os isolados BSV-20, BSV-18, BSV-17, BSV-07 e BSV-12 inibiram significativamente infecções de antracnose em frutos de pimenta em pós-colheita.

scholarly journals The Role of Chitinase Production by Stenotrophomonas maltophilia Strain C3 in Biological Control of Bipolaris sorokiniana

2000 ◽  
Vol 90 (4) ◽  
pp. 384-389 ◽  
Author(s):  
Zhongge Zhang ◽  
Garry Y. Yuen
Keyword(s):  
Biological Control ◽  
Antifungal Activity ◽  
Leaf Spot ◽  
Wild Type Strain ◽  
Bipolaris Sorokiniana ◽  
Chitinase Activity ◽  
Wild Type ◽  
Chitinase Production

The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (>8 kDa) was chitinolytic and more inhibitory than a low-molecular-weight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity chromatography also were chitinolytic and highly antifungal. The chitinolytic fractions caused swelling and vacuolation of conidia and discoloration, malformation, and degradation of germ tubes. When boiled, the chitinolytic fractions lost chitinase activity along with most of the antifungal properties. Two chitinase-deficient and two chitinase-reduced mutants of C3 were compared with the wild-type strain for inhibition of germination of B. sorokiniana conidia on tall fescue leaves and for suppression of leaf spot development in vivo. The mutants exhibited reduced antifungal activity and biocontrol efficacy, but did not lose all biocontrol activity. An aqueous extract of leaves colonized by wild-type C3 had higher chitinase activity than that of noncolonized leaves and was inhibitory to conidial germination. The addition of chitin to leaves along with the wild-type strain increased both chitinase and antifungal activity. The chitinase activity level of extracts from leaves colonized by a chitinase-deficient mutant of C3, with and without added chitin, was no higher than the background, and the extracts lacked antifungal activity. Chitinolysis appears to be one mechanism of biological control by strain C3, and it functions in concert with other mechanisms.

scholarly journals Biological Control of Ceratocystis fimbriata by Bacillus subtilis on Acacia mearnsii Seedlings

2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Ricardo Mezzomo ◽  
Graziela Piveta ◽  
Marília Lazarotto ◽  
Clair Walker ◽  
Caciara Gonzatto Maciel ◽  
...  
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Acacia Mearnsii ◽  
Ceratocystis Fimbriata ◽  
Before And After ◽  
Pathogenicity Tests ◽  
Antagonistic Potential ◽  
Black Wattle

ABSTRACT The aim of this study was to evaluate the effect of Ceratocystis fimbriata isolates, obtained from Actinidia deliciosa (kiwifruit), on black wattle (Acacia mearnsii De Wild.) seedlings, the potential biological control exerted in vitro by Bacillus subtilis on C. fimbriata, and the in vivo effect of B. subtilis against C. fimbriata on black wattle seedlings. Isolates of C. fimbriata obtained and identified from kiwi plantations were used in pathogenicity tests on A. mearnsii seedlings. In vitro, the antagonistic potential of B. subtilis on the pathogen was analyzed by direct confrontation tests. To evaluate the effect of B. subtilis in vivo, black wattle seedlings were inoculated with Rhizolyptus® seven days before and after pathogen inoculation. On black wattle seedlings, C. fimbriata isolates caused 44,15% to 100% severity. Direct confrontation tests revealed that the strains were effective in the biological control of C. fimbriata isolates in vitro. In vivo, Rizolyptus® was not efficient in controlling C. fimbriata.

In vitro inhibition of plant pathogens by Bacillus subtilis and Enterobacter aerogenes and in vivo control of two postharvest cherry diseases

1986 ◽  
Vol 32 (12) ◽  
pp. 963-967 ◽  
Author(s):  
R. S. Utkhede ◽  
P. L. Sholberg
Keyword(s):  
Bacillus Subtilis ◽  
Verticillium Dahliae ◽  
Enterobacter Aerogenes ◽  
Brown Rot ◽  
Pathogenic Fungi ◽  
Pythium Ultimum ◽  
Colletotrichum Lindemuthianum ◽  
Plant Diseases ◽  
Armillariella Mellea

Twenty-one isolates of the bacterium Bacillus subtilis and one of Enterobacter aerogenes were tested on agar for antagonism to Alternaria alternata, Armillariella mellea, Botrytis allii, Botrytis cinerea, Colletotrichum lindemuthianum, Monilinia fructicola, Penicillium expansum, Phytophthora cactorum, Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium cepivorum, Verticillium dahliae, and Venturia inequalis, causal organisms of many plant diseases. Enterobacter aerogenes was antagonisic to all of the pathogenic fungi tested except Verticillium dahliae and Armillariella mellea. Similarly, Bacillus subtilis was antagonistic to all of the pathogenic fungi tested except Pythium ultimum. When Enterobacter aerogenes and Bacillus subtilis were tested in vivo on cherry fruit for control of postharvest brown rot and alternaria rot, Enterobacter aerogenes was ineffective. Eleven isolates of Bacillus subtilis provided effective alternaria rot control and 15 isolates provided brown rot control which ranked with the best fungicide control.

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