Open AccessANTAGONISTIC ACTIVITY OF SOIL MICROORGANISMS AS AN EFFECTIVE MEANS OF PLANT PROTECTION AGAINST ACCREMONIOSIS
Author(s) -
Г. В. Цехмістер,
A. S. Kyslynska,
A. A. Pavlenko
Publication year - 2019
Publication title -
sìlʹsʹkogospodarsʹka mìkrobìologìâ
Language(s) - English
Resource type - Journals
ISSN - 1997-3004
DOI - 10.35868/1997-3004.30.46-53
Subject(s) - microorganism , mycelium , antagonism , fungus , trichoderma , agar , biology , chaetomium , chaetomium globosum , agar plate , microbiology and biotechnology , pathogen , botany , penicillium , bacteria , food science , biochemistry , genetics , receptor
Objective. Screening of microorganisms — antagonists of the phytopathogenic fungus Acremonium cucurbitacearum. Methods. The antagonistic activity of microorganisms was investigated by the method of mixed (counter) cultures on wort agar. The appearance and type of relationships were registered using Simonian and Mamikonian modified scale. The primary screening of A. cucurbitacearum 502 antagonists was performed by the delayed antagonism method. Morphological and cultural characteristics of Triсhoderma sp. 017 were studied on wort agar. The fungus was grown for 10 days. Results. Almost all of the microorganisms under study were found to exhibit antagonistic properties against A. cucurbitacearum 502. In particular, among bacteria, Bacillus sp. 23 exhibited the highest antifungal activity and inhibited the growth of the pathogen even after 25 days of their compatible cultivation. Screening for micromycetes of the genera Trichoderma and Chaetomium showed that all the tested strains showed antagonistic activity to A. cucurbitacearum 502 to one extent or another. Following contact of Chaetomium fungi — C. globosum 377 and C. cochliodes 3250 with A. cucurbitacearum 502, they delayed growth of the latter, showing superparasitism at Day 25 and 15, respectively. Among the fungi of the genus Triсhoderma, strain Triсhoderma sp. 017 was characterized by the fastest growth and at Day 5 of cultivation showed superparasitism, arresting the growth of A. cucurbitacearum 502 and completely invading the colony of pathogen. Colonies of the fungus Trichoderma sp. 017 on wort agar show rapid growth, forming a white mycelium film and a dark green conidial zone. The optimum pH is 5.0. The mycelium consists of colourless, smooth, strongly branched hyphae, 2.5‒6.0 μm in diameter. Conidiophores are very branched in compact or loose pads, with a main axis, 3.5‒4.0 µm thick. Sterigmata form rings with 2‒3 sterigmata varying in size, 6.25‒15.0 × 2.5‒3.0 μm. Conidia are spherical 2.0‒3.0 × 3.5‒5.0 μm. Conclusion. Therefore, in order to protect plants from acremoniasis caused by the phytopathogen A. cucurbitacearum, we suggest the strain Triсhoderma sp. 017, which is characterized by the most rapid growth and active superparasitism. According to morphological and cultural characteristics, the fungus is classified as T. viride 017.