Pugliese M, Gullino M L, Garibaldi A
University of Torino, Centre of Competence for the Innovation in the agro-environmental field (AGROINNOVA), Via L. da Vinci 44, IT-10095 Grugliasco (TO), Italy.
Commun Agric Appl Biol Sci. 2010;75(4):665-9.
Suppression of soil-borne plant pathogens with compost has been widely studied. Compost has been found to be suppressive against several soil-borne pathogens in various cropping systems. However, an increase of some diseases due to compost usage has also been observed, since compost is a product that varies considerably in chemical, physical and biotic composition, and, consequently, also in ability to suppress soil borne diseases. New opportunities in disease management can be obtained by the selection of antagonists from suppressive composts. The objective of the present work was to isolate microorganisms from a suppressive compost and to test them for their activity against soil-borne pathogens. A compost from green wastes, organic domestic wastes and urban sludge's that showed a good suppressive activity in previous trials was used as source of microorganisms. Serial diluted suspensions of compost samples were plated on five different media: selective for Fusarium sp., selective for Trichoderma sp., selective for oomycetes, potato dextrose agar (PDA) for isolation of fungi, lysogeny broth (LB) for isolation of bacteria. In total, 101 colonies were isolated from plates and tested under laboratory conditions on tomato seedlings growing on perlite medium in Petri plates infected with Fusarium oxysporum f.sp. radicis-lycopersici and compared to a commercial antagonist (Streptomyces griserovidis, Mycostop, Bioplanet). Among them, 28 showed a significant disease reduction and were assessed under greenhouse condition on three pathosystems: Fusarium oxysporum f.sp. basilica/basil, Phytophthora nicotianae/tomato and Rhizoctonia solani/bean. Fusarium spp. selected from compost generally showed a good disease control against Fusarium wilts, while only bacteria significantly controlled P. nicotianae on tomato under greenhouse conditions. None of the microorganisms was able to control the three soil-borne pathogens together, in particular Rhizoctonia solani. Results confirmed the good suppressive activity of the compost under study against soil-borne pathogens. The selection of antagonists from compost is a promising strategy for the development of new biological control agents against soil-borne pathogens.
利用堆肥抑制土传植物病原菌已得到广泛研究。研究发现，堆肥对各种种植系统中的多种土传病原菌具有抑制作用。然而，由于堆肥是一种化学、物理和生物组成差异很大的产品，因此其抑制土传病害的能力也有所不同，人们也观察到因使用堆肥而导致某些病害增加的情况。通过从抑制性堆肥中筛选拮抗菌，可以获得病害管理的新机会。本研究的目的是从一种抑制性堆肥中分离微生物，并测试它们对土传病原菌的活性。一种由绿色废弃物、家庭有机垃圾和城市污泥制成的堆肥在先前试验中表现出良好的抑制活性，被用作微生物来源。将堆肥样品的系列稀释悬浮液接种在五种不同的培养基上：用于镰刀菌属的选择性培养基、用于木霉属的选择性培养基、用于卵菌的选择性培养基、用于分离真菌的马铃薯葡萄糖琼脂（PDA）、用于分离细菌的溶菌肉汤（LB）。总共从平板上分离出101个菌落，并在实验室条件下对生长在珍珠岩培养基上、感染了番茄根腐镰刀菌的番茄幼苗进行测试，并与一种商业拮抗菌（灰色链霉菌，Mycostop，Bioplanet）进行比较。其中，28种表现出显著的病害减轻，并在温室条件下在三种病害体系中进行评估：尖孢镰刀菌/罗勒、烟草疫霉/番茄和立枯丝核菌/菜豆。从堆肥中筛选出的镰刀菌属通常对枯萎病表现出良好的病害控制效果，而在温室条件下，只有细菌能显著控制番茄上的烟草疫霉。没有一种微生物能够同时控制这三种土传病原菌，尤其是立枯丝核菌。结果证实了所研究的堆肥对土传病原菌具有良好的抑制活性。从堆肥中筛选拮抗菌是开发新型土传病原菌生物防治剂的一种有前景的策略。
