Biological Control of Root-Knot Nematodes (Meloidogyne Spp.): Microbes Against the Pests
Total Page：16
File Type：pdf, Size：1020Kb
COBISS Code 1.02 DOI: 10.2478/acas-2013-0022 Agrovoc descriptors: biological control, control methods, nematoda, microorganisms, microbial pesticides, biopesticides, biological control organisms, bacteria, fungi, meloidogyne, meloidogynidae Agris category code: h10 Biological Control of Root-Knot Nematodes (Meloidogyne spp.): Microbes against the Pests Janja LAMOVŠEK1, Gregor UREK2, Stanislav TRDAN3 Received August 12, 2013; accepted September 23, 2013. Delo je prispelo 12. avgusta 2013, sprejeto 23. septembra 2013. ABSTRACT IZVLEČEK Root-knot nematodes (Meloidogyne spp.) are important pests BIOTIČNO ZATIRANJE OGORČIC KORENINSKIH of many cultivated plants. Recently, the most efficient ŠIŠK (Meloidogyne spp.): MIKROORGANIZMI PROTI chemical control products (e.g. methyl bromide) have now ŠKODLJIVCEM been restricted due to their toxic characteristics. Research on agents that work against root-knot nematodes and do not have Ogorčice koreninskih šišk (Meloidogyne spp.) uvrščamo med a detrimental impact on the environment is becoming pomembne škodljivce številnih kmetijskih rastlin. Najbolj increasingly important. Advances in the last decades produced učinkovita kemična sredstva za njihovo zatiranje so močno quite a number of biocontrol products that are already strupena, zato je njihova uporaba močno omejena ali celo marketed. Some of the well-accepted commercial products prepovedana (npr. metil bromid). Razvoj na področju contain bacteria Bacillus firmus and Pasteuria penetrans, and pripravkov za zatiranje ogorčic koreninskih šišk z okoljsko fungus Purpureocillium lilacinus. In this review we sprejemljivimi lastnostmi se povečuje. Napredek v zadnjih summarize the antagonistic activity of bacteria and fungi, with desetletjih je viden v večjem številu biotičnih pripravkov, their advantages and limitations in biocontrol of root-knot mnogi med njimi se danes že tržijo. Aktivne snovi v nematodes. uveljavljenih biotičnih sredstvih sta bakteriji Bacillus firmus in Pasteuria penetrans ter gliva Purpureocillium lilacinus. V Key words: biological control, Meloidogyne spp., članku je predstavljen pregled zaviralnih mehanizmov antagonisms, bacteria, fungi, commercial delovanja bakterij in gliv, prav tako omenjamo največje products prednosti in slabosti njihove uporabe v biotičnem zatiranju ogorčic koreninskih šišk. Ključne besede: biotično varstvo rastlin, Meloidogyne spp., antagonizem, bakterije, glive, tržni pripravki 1 INTRODUCTION: OLD VS. MODERN PLANT PEST CONTROL STRATEGIES The success of pesticides in the middle of the 20th frequently by becomming resistant. Recently, the century enabled control of many harmful importance of healthly food and identification of organisms. Unfortunately, the adaptation of plant- environmental hazards inclined the research field damaging organisms was not accounted for. The toward alternative control disease strategies by pesticides introduced new environmental focusing on biological control agents. conditions to which plant pathogens had to adapt, 1 Young Researcher, B.Sc. Microbiology, Agricultural Institute of Slovenia, Plant Protection Department, Hacquetova ulica 17, SI-1000 Ljubljana, Slovenia, e-mail: [email protected] 2 Assist. Prof., PhD, Agricultural Institute of Slovenia, Plant Protection Department, Hacquetova ulica 17, SI-1000 Ljubljana, Slovenia 3 Assoc. Prof., University of Ljubljana, Biotechnical Faculty, Dept. of Agronomy, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia Acta agriculturae Slovenica, 101 - 2, september 2013 str. 263 - 275 Janja LAMOVŠEK et al. Plant parasitic nematodes are important pests of The concerns at this point are methods of many cultivated plants. The Meloidogyne genus controlling Meloidogyne spp. in soil because no belongs to a group of root-knot nematodes (RKN) effective nematicides are available. The public and is represented by over 90 species that have concern over the chemical nematicides is not only been described so far (Moens et al., 2009). These their toxicity but also their loss of efficiency after a are ubiquitous soil organisms with a wide host prolonged use. In 2005, the EU banned the use of range. From financial standpoint the most methyl bromide which was the most effective damaging species are M. incognita, M. javanica, nematicidal agent. The use of other nematicides and M. arenaria (Sasser et al., 1982). The RKN has been restricted or withdrawn recently produce galls on roots that eventually lead to (reviewed in Wesemael et al., 2011). Still useful reduced water uptake to shoots. The severeness of but not entirely effective are management yield loss can range from minimal to total strategies focusing on prevention rather than depending on the infesting RKN species and crop curation. These practices are an improvement of variety, season, soil type and use of crop rotation old practices. Among them are agrotechnical (Sikora and Fernández, 2005; reviewed in measures to restore and maintain healthy soils Wesemael et al., 2011). The tropic group of (removal of plant debris, solarisation of soil, crop Meloidogyne spp. thrive in hot climates but can rotation with plant species immune to pathogens survive in temperate climate conditions also that harm other rotation crops, soil fallow, and (Strajnar et al., 2011). Importing plants and addition of organic amendments), use of pathogen- seedlings infested with RKN from tropic to free seeds and resistant varieties, and biological temperate climates promotes their spread, which is control, which emerged as an alternative to especially important in greenhouses where chemical control (reviewed in Collange et al., temperatures are suitable for RKN reproduction 2011). (reviewed in Wesemael et al., 2011). 2 BIOLOGICAL CONTROL – NATURAL INTERACTIONS IN FOCUSED ACTIONS Soil is a complex ecosystem, one that harbours 2.1 The action: specific vs. non-specific many different organisms with a complex network The microorganisms with the ability to control of interactions. In rhizosphere where nutrients are plant parasitic nematodes belong to bacteria, fungi, abundant the soil organisms have to compete for and actinomycetes. They exert antagonistic action food sources. Biological control exploits these through various mechanisms. Non-pathogenic interactions to either protect the host plant from bacteria antagonize the nematodes by (1) inducing infections or to reduce the severity of the disease. plant resistance (induced or systemic resistance), In short, biological control uses microbes to by (2) degrading signalling compounds to which control plant pathogens. The pioneer of nematode the nematodes are attracted to, or (3) simply by biocontrol was Duddington in 1951. Since then the colonizing the roots thus blocking the penetration research has led to a production of various of infective juveniles. Some microbes produce commercial biological control products containing toxic compounds that kill the nematodes, others live microorganisms or their metabolites that target (e.g. fungi) parasitize on them. All these specific nematode hosts, though their low efficacy mechanisms can be affected by multiple factors, on the fields remains an issue. We will focus on biotic or abiotic, which limit their use in biological live microbe action towards the RKN; products control (Sikora, 1992). based on microbial metabolites are classified as biopesticides and their registration resembles that of chemical pesticides. 264 Acta agriculturae Slovenica, 101 - 2, september 2013 Biological Control of Root-Knot Nematodes (Meloidogyne spp.): Microbes against the Pests 3 ACTIVE INDIGREDIENTS IN BIOLOGICAL CONTROL PRODUCTS Each soil has the capacity to limit the Meloidogyne 2005). The most common endoparasite of spp. reproduction to a certain degree, the rest Meloidogyne spp. is P. penetrans (Stirling, 1985) depends on the activity of native microbial and P. hartismeri in Meloidogyne ardenensis community in soil (Sikora, 1992). Research on (Bishop et al., 2007). Meloidogyne-suppresive soils revealed a high microbial diversity (Bent et al., 2008). Microbial Pasteuria-infected female nematodes produce low groups with highest suppressive potential are (1) numbers of eggs. The endospores are resistant to pathogenic fungi infecting nematode eggs; (2) drying and have good shelf-life; they also reduce rhizobacteria; (3) fungi with a general antagonising infectivity of the juveniles and fecundity of the effect; (4) endophytic fungi, and (5) obligate females (Mankau and Prasad, 1977; Davies et al., parasitic bacteria (Whipps and Davies, 2000). 1988; Chen et al., 1996). Unfortunatelly, their narrow host range limits their wide use, and mass Most promise for RKN (Meloidogyne spp.) endospore production is currently hard to achieve. biological control show fungi from Trichoderma The Pasteuria Biosciences LLC (recently aquisited and Purpureocillium genera (Dababat et al., 2006; by Syngenta) is the only company able to produce Affokpon et al., 2011; Wilson and Jackson, 2013), enough endospores in a bioreactor to accomodate endospores of Pasteuria penetrans, and small field trials (Hewlett at al., 2004; 2006). They rhizobacteria (e.g. Bacillus firmus) that are already overcame the obstacle of obligate living conditions marketed (Wilson and Jackson, 2013). by regulating the activity of the sporulating protein Spo0F (Kojetin et al., 2005). 3.1 Bacteria and antagonists Plant-parasitic nematodes co-exist in rhizosphere Endospores have different binding affinities to with biologically diverse bacterial communities. infective juveniles J2. The attachment of These