HK1200192B - Saccharomyces cerevisiae strains with phytosanitary capabilities - Google Patents

Description

Saccharomyces cerevisiae strain with plant disease control capability

The application is a divisional application with the application date of 26/1/2010 and the application number of 201080005774.3 in China, and the invention name of the application is 'Saccharomyces cerevisiae strain with the capability of controlling plant diseases'.

Technical Field

The invention

Relates to Saccharomyces cerevisiae, which is useful as an antagonistic microorganism for protecting plants against various pathogens, in particular fungi. The invention is suitable for treating a plurality of plant varieties.

Background

Among the pathogens of plants, the fungi that cause fungal diseases or cryptogamic diseases are the pathogens with the greatest economic impact. Each plant species is susceptible to one or several major diseases which can strongly reduce its robustness, its growth and ultimately the quantity or/and quality of the harvest.

Various parameters influence the development of disease, for example: soil conditions and fertilization, variety sensitivity, cultivation methods (crop rotation, cultivation, number of plants or seedlings per hectare, pruning systems, etc.), or especially climatic conditions. However, in general, acting on some of these factors is not sufficient to adequately limit damage caused by disease. Furthermore, as a safeguard against this disease, practitioners wishing to optimize and ensure their yield will treat their cultures at the correct time with products that control plant diseases, often preventively. In the most common cases, the products used are chemical products, most of which are highly effective but present health hazards to the operators and produce residues in the treated products, soil and water. Furthermore, repeated use of certain fungicidally active substances acting on the same metabolic site selects strains resistant to these fungicides.

In an attempt to find a remedy to this problem, it is necessary to limit the use of the same chemical class each year, to switch to a chemical product class with a different mode of action, and to adopt other methods that are detrimental to the pathogen. Thus, in the context of this document, there is a real and obvious need for alternative solutions to plant diseases.

Ideally, these solutions should function in a manner different from existing chemical fungicides, should not produce any chemical residue in the harvest and environment, and be safer and healthier for the operator. Such treatments should be used alone or in combination with the chemical treatment of the invention or any other treatment for preventing the appearance of these pathogens and their resistant strains on plants or for limiting the growth of these pathogens and their resistant strains on plants and for limiting the harm to humans and the environment.

In the present context, it is known how to apply antagonistic microorganisms of pathogens to plants. For example, microorganisms so far referred to as antagonistic microorganisms include bacteria: bacillus subtilis, fungi: trichoderma harzianum, trichoderma viride, coniothyrium minitans, streptomyces griseoviridis, yeasts: aureobasidium pullulans, Metschnikowiafrrucicola, Candida oleophilic (Candidaolophia). The article by ElGhauth et al, "biological control of post-harvest diseases in fruits and vegetables" (applied mycologyand Biotechnology, Vol.2, Agricultureandfoodproduction, ElsevierScience B.V, p.219-238) presents an overview of biological control of pathogens on fruits and several possible explanations of the antimicrobial mode of action.

The invention also relates to the use of saccharomyces cerevisiae as an antagonistic microorganism. However, it has been estimated that in general the efficacy of these yeasts is lower than that of other microorganisms, or even zero in some cases. By way of example, reference may be made to the article written by A.B. Filonow "competition of sugars in yeast in the biological control of Botrytis cinerea" (biocontrol science and technology, 8: 243. sup. 256, 1998), which teaches that, unlike Cryptococcus laurentii (Cryptococcus laurentii) and Sporobolomyces (Sporobolomyces), Saccharomyces cerevisiae is not effective in reducing infection of apples by Botrytis cinerea.

Now, antagonistic microorganisms, which are generally considered to be the most effective, are often isolated from the natural environment and are not well known, and thus may exhibit undesirable characteristics during their development and use. Then, people are faced with problems of industrialization or even with drawbacks for people or the environment.

Therefore, there is a need to develop new strains of antagonistic microorganisms that are more stable from an industrial point of view, safer from a health and environmental point of view, and effective in controlling diseases caused by pathogens in plants.

Disclosure of Invention

The invention relates firstly to a strain of saccharomyces cerevisiae, characterized in that it is selected from the strain deposited under accession number I-3936 at french national collections of microorganisms ("collections of microorganisms", institute of pasteur, 25 rueda country reux, 75724paris cedex15, france) at 3.4.2008, the strain deposited under accession number I-3927 at 3.4.2008, the strain deposited under accession number I-3938 at 3.4.2008 at french national collections of microorganisms, and the strain deposited under accession number I-3939 at 3.4.2008 at french national collections of microorganisms.

The present invention also relates to a composition for controlling plant diseases, comprising saccharomyces cerevisiae selected from the group consisting of the strain deposited at french national collection of microorganisms at 3 and 4 months 2008, and the strain deposited at french national collection of microorganisms at I-3939 days at 2008, and a mixture thereof.

According to one embodiment, the composition for controlling plant diseases further comprises more than one formulation and/or at least one additional active adjuvant.

According to one embodiment, the plant disease controlling composition is a concentrated plant disease controlling composition, which is a solid or liquid dry formulation.

According to one embodiment, the plant disease controlling composition is a ready-to-use composition for controlling plant diseases, in a dry or liquid formulation, preferably a liquid formulation.

According to one embodiment, the composition for controlling plant diseases is contained at 10⁴To 10¹¹Between cfu/ml, preferably 10⁵To 10¹⁰Between cfu/ml, more preferably 5 × 10⁵To 5 × 10⁹An amount of between cfu/ml of Saccharomyces cerevisiae.

The present invention also relates to a method for treating or protecting a plant from a disease caused by a pathogen, comprising contacting the plant with saccharomyces cerevisiae selected from the group consisting of the strain deposited at french national collection of microorganisms at 3-4.2008, and a mixture thereof.

According to one embodiment, the pathogen is selected from the group consisting of fungi, viruses, bacteria, mycoplasma, spiroplasma, viroids and combinations thereof, preferably a fungus.

According to one embodiment, the pathogen is a microorganism selected from the group consisting of: alternaria (Alternaria spp.), in particular Alternaria solani (Alternaria) and Alternaria alternata (Alternaria), Chaetomium (Ascocytaspp.), in particular Chaetomium (Ascochytapaceae) or Ascochytapodenum fabarum, Aspergillus, in particular Aspergillus niger and Aspergillus fumigatus, Botrytis, in particular Botrytis cinerea, Bremia (Bremia spp.), in particular Bremia lactuca (Bremia lactucae), Cercospora (Cercospora spp.), in particular Cercospora betaine (Cercospora beta.), Cladospora (Cladosporium sp.), in particular Cercospora terrestris (Cercospora rosea), in particular Cephalosporium cepa (Cladosporium sp.), in particular Cladosporium (Cladosporium sp.), in particular Fuscoporia rosea), in particular Fuscoporia graminis (Fuscoporia oxysporium), in particular Fuscoporia rosea (Fuscoporia), in particular Fuscoporia oxysporium (Fusarium) and Fusarium (Fuscoporia oxysporum), in particular Fusarium (Fusarium) and Fusarium (Fusarium oxysporum (Fusarium) in particular Fusarium (Fusarium) in the genus of the genus Fusarium (Fusarium) or Fusarium (Fusarium) in particular Fusarium (Fusarium) in the genus Fusarium (Fusarium) or Fusarium (Fusarium) in the genus of the genus Fusarium) or Fusarium (Fus, The genera of the species coccidiodes (Guignardiaspp.), in particular Staphylococcus coccinellii (Guignardiabidwellii), Helminthosporium (Helminthosporium spp.), in particular Helminthosporidium-repeniis, Discospora (Marssonina spp.), in particular Rosa serrulata (Marssorosa), Pleurospora sp, in particular Peilosporium praecox (Monilia spp.), in particular Peilospora praecox (Monilia fregatigen), Mycosphaerella (Mycosphaerellasporium), in particular Brassica campestris (Mycosphaerasporicola), Penicillium (Penicillium spp.), in particular Penicillium expansum (Penicillium praecosporium) or Penicillium digitatum, in particular Penicillium praecospora (Pseudomyces praecospora), in particular Pseudomonas aeruginosa, Poisseria (Phospongiella sp.), in particular Pseudomonas sp, in particular Phosphorocapsilaea (Phosphaerella), in particular Pseudomonas sp), Pseudomonas sp, in particular Pseudomonas sp, in particular Pseudomonas sp. In particular Pseudoperonospora cubensis (Pseudoperonospora cubensis), Pseudoperonospora (Pseudoperonospora sclerotiorum), in particular Pseudoperonospora medicaginosa (Pseudoperonospora zizamedeca), Puccinia puccinia (Pucciniaspp.), in particular Puccinia graminis (Pucciniavein), Pythium (Pyrethium spp.), Podocarpospora (Ramularia spp.), in particular Stachyurospora glaucocalyx (Ramularia), Rhizoctonia (Rhizoctoniensis), in particular Rhizoctonia solani (Rhizoctonia sep), in particular Rhizoctonia solani (Septoria septoria), in particular Rhizophora nigrostreatus (Rhizoctoniensis), in particular Rhizophora nigripes (Rhizoctonia roseospora), in particular Rhizophora nigrospora roseospora (Spirospora), in particular Rhizophora roseospora (Spirospora), in particular Sphingospora roseospora (Spirospora), Sphingoticola (Sphingospora), in particular Sphingotiopsis), Sphingospora (Sphingospora), Sphingospora (Rhizoctonia), in particular Sphingoticola (Sphingospora), Sphingoticola (Rhizoctonia), Sphingospora), Sphingoticola (Rhizoctonia), in particular Sphizomorph (Spirostricola (Sphingosporispora), Spiro (Spirostricola (Sphizomorph), Spirochaetomium (Spiro (Spirostricola), Spirochai), Spirochaetomium (Sphizomorph), Spirochaetomium (Spirochai), Spirochaetomium (Spirochai), Spirochaeto, Devil's claw (Uncinula spp.), especially grape devil's claw (Uncinula necator), Ustilago (Ustilago spp.), especially Ustilago tritici (Ustilago tritici), Venturia (Venturia spp.), especially Venturia inaequalis (Venturia aqualis), and combinations thereof; preferably the pathogen is selected from the group consisting of penicillium digitatum, penicillium expansum, botrytis cinerea and combinations thereof.

According to an embodiment, the plant is selected from the group consisting of graminaceous plants, dicotyledonous plants, annual plants, secondary and perennial plants, seedlings of vegetables or harvested vegetables, fruit bearing plants or trees or harvested fruits, flower bearing plants or trees or harvested flowers, cereals, oil bearing plants, protein producing (proteaginous) plants, woody plants, ornamental plants, in particular from the group consisting of plantlets or products derived from potato, beetroot, sugarcane, tobacco, vine, wheat, rapeseed, barley, rice, maize, sorghum, millet (millet), soybean, beans, tomato, cucumber, lettuce, strawberry plants, apple trees, pear trees, citrus, banana, pineapple, peach trees, apricot trees, cherry trees, walnut trees and hazelnuts.

According to one embodiment, the method comprises:

applying the ready-to-use plant disease control composition to the whole or part of the plant; or

The above-described concentrated plant disease-controlling composition is mixed with a formulation to form a final plant disease-controlling composition, and then the final plant disease-controlling composition is applied to the whole body or part of the plant.

According to one embodiment, the application of the plant disease controlling composition to the whole body or part of said plant consists of applying the composition to the foliage, stems, flowers, fruits, trunks and/or roots or parts thereof, preferably by spraying, preferably by ground spraying, mechanical blending, mixing with fertilizers, fortifiers or in the form of premixes to the roots.

The invention can overcome the defects of the prior art. In particular, the present invention provides novel strains of antagonistic microorganisms that are more stable from an industrial point of view, safer from a health and environmental point of view, and effective in controlling diseases caused by pathogens in plants.

The invention is based on the development by the present inventors of a new strain of Saccharomyces cerevisiae having a very good ability to control plant diseases. Since saccharomyces cerevisiae is a known yeast species and has been used in the manufacture of bread and wine, including on an industrial scale for centuries, its use as an antagonistic microorganism is particularly advantageous.

Thus, it is possible to effectively control plant pathogens and diseases caused by pathogens by using products that are not harmful or very harmful to humans and the environment and that are easy to produce on an industrial scale.

According to a particular embodiment of the invention, the invention also has one, or preferably several, of the following advantageous features:

the present invention provides long-term plant protection (e.g., 1 week, 2 weeks, or more than 1 month) and multivalent effects against multiple pathogens;

the invention is particularly applicable to the field of biological agriculture;

the present invention can increase the overall efficacy of plant protection by reducing infection levels and/or reducing inoculum remission;

the present invention makes it possible to limit the residual amount of agrochemicals on (or in) consumer products as well as in soil and water during the treatment of cultures or plants.

Description of the preferred embodiments

The invention will now be illustrated in more detail in the following description in a non-limiting manner.

Type of treatment (therapeutic or prophylactic)

As previously mentioned, the present invention relates to methods and products for prophylactically or therapeutically controlling pathogens in plants.

The relevant plants may be any type of plant, in particular graminaceous and dicotyledonous plants, annual plants, secondary and perennial plants, vegetables, cereals, including wheat, barley and rice, maize, sorghum, millet, oleaginous plants, protein (proteinous) plants, potatoes, sugar beet roots, sugar cane, tobacco, woody plants, fruit or non-fruit trees, vines, ornamental plants, and the like.

According to a particular embodiment, the plant is a fruit tree, for example of the seed type, in particular chosen from the apple tree, the pear tree and the citrus tree.

According to another embodiment, the plant is selected from the group consisting of a vine, a cereal (in particular wheat), a rapeseed, a beetroot, a potato, a bean, a tomato, a cucumber, a lettuce or a strawberry plant.

The term "plant" as used within the scope of the present invention encompasses plants (e.g. fruit trees and the like) and isolated parts of these plants, such as harvested fruits or flowers, but also grain or seeds (plant propagation material).

According to a particular embodiment, the plant is a fruit, such as an apple, or a pear, or a citrus.

Hereinafter, when contacting a plant with the composition, it is to be understood that such contacting may be carried out on the entire surface of the plant or only a portion of the surface. For example, when the plant is a whole plant, the contacting may be performed on all of the plant or on more than one part of the plant (e.g., leaves, stems, flowers, fruits, trunks, and/or roots) or only a portion of the surface of such leaves, stems, flowers, fruits, trunks, and/or roots.

The product of the invention is able to effectively protect plant fruits against pathogens in cold conditions for a considerable period of time, which may exceed one month, or even several months. Of course, repeated administrations at intervals determined by the user can be contemplated.

The invention can be used to control any type of pathogen, in particular fungi, viruses, bacteria, mycoplasma, spiroplasma or viroids. The present invention is particularly effective in controlling fungi.

As specific examples of pathogens, fungi of the following genera are specifically enumerated: alternaria, such as Alternaria solani and Alternaria alternata, Ascopytapanodella, such as Ascochyta or Ascocytapanodella, Aspergillus, in particular Aspergillus niger and Aspergillus fumigatus, Botrytis, such as Botrytis cinerea, Bremia, such as Bremia lactucae, Cercospora, such as Brettanomyces, Cladosporium, such as Cladosporium cepacia, Anthragmatis, such as Anthragmatis graminis, Cryptosporidium, in particular Cryptosporidium humicola, Erysiphelus, such as Microtoena or Erysiphelus, Fusarium, such as Fusarium oxysporum and Fusarium roseum, Penicillium, such as Helminthosporium, Hypocrea, such as Pseudosporidium torulosum, Sphaerothecium, Penicillium, such as Penicillium, or Penicillium, Sphaerothecium, such as Penicillium roseum, Sphaerothecium, and Brevibacterium, Peronospora, for example Peronospora parasitica, Peziculaspp, in particular Peziculamalicortici, Polychaetobacter, for example Phragmidiumbrubii, Phytophthora, including Phytophthora infestans, Plasmopora, including Plasmopora, Sphaerotheca, for example Sphaerotheca fuliginospora, Pseudocercospora, including Pseudocercospora erulea, Pseudoperonospora, for example Pseudoperonospora cubensis, Pseudocercospora, for example Pseudocercospora, Puccinia, including Puccinia, Pythium, Stylosporium, including Stachybotrytis, Rhizoctonia, for example Rhizoctonia solani, Rhizopus, for example Rhizopus nigricans and Rhizopus, Rhinochlorospora, for example Rycnospora, Scleroticus, for example Sclerotiopsis nodorum, for example Rhizoctonia cerealis, or Sphaerotheca, such as Sphaerotheca, in particular Sphaerotheca, especially Sphaerotheca, and Sphaerotheca, such as, Uncaria species, such as Uncaria botrytis, Ustilago species, such as Ustilago tritici, Ustilago species, such as apple scab. Combinations of the above pathogens may also be controlled by the present invention.

Penicillium digitatum, Penicillium expansum and Botrytis cinerea are particularly effective species of the present invention.

Examples of bacteria affecting cultivated crops include in particular: corynebacterium, Brevibacterium, Streptomyces, Pseudomonas, Xanthomonas, Erwinia, especially Erwinia pestis (Erwinia amylovora), Erwinia carotovora (Erwinia carotovora), and Erwinia chrysanthemi (Erwinia chrysogenmi).

Examples of viruses which affect cultivated crops are, for example, tobacco mosaic virus or potato virus Y.

The present invention provides a method for the treatment and/or protection of plants against diseases caused by the above-mentioned pathogens, for example Botrytis cinerea. The method encompasses any therapeutic or prophylactic method aimed at delaying or preventing the occurrence of these diseases, eradicating the diseases, or limiting or reducing the scale, extent or effect of these diseases.

Saccharomyces cerevisiae strains as antagonistic microorganisms

By "antagonistic microorganism" is meant a microorganism which is within the scope of the present invention an antagonist of a pathogen, in particular a pathogen which is likely to cause plant disease (in particular one of the pathogens listed above).

The present invention provides four strains of saccharomyces cerevisiae that can be used as antagonistic microorganisms, namely:

strain accession No. I-3936, deposited at 4/3/2008 in french national collections of microorganisms (CNCM);

the strain deposited at the french national collections of microorganisms (CNCM) on 4 days 3/2008 as accession number I-3937;

a strain deposited at the french national collections of microorganisms (CNCM) on 4/3/2008 with accession number I-3938; and

strain accession No. I-3939, deposited at 4/3/2008 in french national collections of microorganisms (CNCM).

Application of Saccharomyces cerevisiae strain

The present invention provides the use of the aforementioned strain of saccharomyces cerevisiae for protecting or treating plants against diseases caused by pathogens.

In particular, to achieve this object, the present invention provides a plant disease controlling composition comprising one of the aforementioned saccharomyces cerevisiae strains (or a mixture of several of these strains).

"composition for controlling plant diseases" means, within the scope of the present invention, a composition capable of protecting plants against one or several pathogens and/or treating plants infected by more than one pathogen.

The plant disease controlling composition according to the present invention may be in a concentrated form or a ready-to-use form. The plant disease controlling composition may be in dry form, for example in the form of a powder or granules, or in liquid form, in particular in aqueous form, for example a suspension, dispersion, gel, cream, paste, or in solid form. In the case of a ready-to-use composition, an aqueous liquid form is preferred, as this form is suitable for spraying.

In dried form, the yeasts of the aforementioned strains are preferably in dehydrated, lyophilized and/or encapsulated form.

In the ready-to-use compositions for controlling plant diseases, active substances for plants (the aforementioned strains of Saccharomyces cerevisiae) have been formulated in an appropriate manner. Thus, the active substance is mixed, for example, with an acceptable carrier, such as a liquid filled spray-type sprayer, a fertilizer, a culture substrate for greenhouses. The ready-to-use composition may be in the form of a powder, but is preferably in liquid form.

Unlike ready-to-use plant disease control compositions intended for application to plants, the concentrated plant disease control composition is intended to be mixed with a formulation (carrier) by the user to form the final ready-to-use composition. Preferably, the formulation is water or an aqueous solution. Therefore, it is common for the user to dissolve the granules (concentrated plant disease-controlling composition) in water, or to dilute the aqueous suspension or dispersion (concentrated plant disease-controlling composition) in water, to obtain the final ready-to-use composition.

If the yeasts are in dehydrated form in the concentrated phytosanitary composition and if the final composition is in liquid form (usually aqueous form), care should be taken to take the usual precautions against rehydrating the yeasts; for example, the temperature of the formulation suitable for dissolution/rehydration (typically water or an aqueous solution) is advantageously between 20 and 25 ℃.

Whether the plant disease control composition is concentrated or ready-to-use, in either case the composition will generally comprise one or several solid or liquid formulations.

The formulation may consist of any compound or any inert material capable of facilitating or optimising the transport, storage, handling, application and/or persistence of the active substance on the plant or part thereof. The formulation is suitable for the desired purpose: retention of the active substance, maintenance of the active substance in suspension during storage or during use in preparing the treatment mixture, anti-foaming, anti-dust, adhesion to plants, penetration into tissues, and other purposes. The formulation or formulations may be solid, liquid; may be used alone or in combination.

The formulation may in particular be selected from surfactants, dispersants, preservatives, wetting agents, emulsifiers, sticking agents, pH buffers, nutrients; can be used alone or in combination.

The amount of Saccharomyces cerevisiae applied to the plant is determined by one skilled in the art, and depends in particular on the pathogen or pathogens treated, the type of plant, the strain, and the combination of strains used, etc. Preferably, the amount applied is sufficient to protect the plant against pathogens or to limit or inhibit the growth and action of the pathogens present. This amount can be obtained, for example, by field trials (or, for example, when the plant is fruit, by laboratory testing, or self-testing at the fruit packaging station).

Preferably, the ready-to-use composition for controlling plant diseases comprises at least one compound of formula 10⁴To 10¹¹Between cfu/ml, preferably 10⁵To 10¹⁰Between cfu/ml, more preferably 5 × 10⁵To 5 × 10⁹A strain of the aforementioned yeasts in an amount between cfu/ml.

The above-described plant disease control compositions, in their final (ready-to-use) form, can be applied to plants in different ways and according to different steps or procedures of treatment. In a preferred embodiment, the composition is a liquid and is applied by spraying, particularly onto foliage or the ground. In a specific embodiment, the composition is a liquid and is applied by spraying on harvested flowers or fruits.

Alternatively, the composition can be applied in a mixture with a fertilizer, a culture support, water spray or other product. Thus, the composition may be applied to the roots by ground spraying, mechanical blending, mixing with fertilizers, enhancers, or in the form of a premix, or other methods.

Other possible active adjuvants

Other active adjuvants may be used within the scope of a preventive or therapeutic treatment against diseases caused by pathogens in plants. "active adjuvant" means any compound (other than the aforementioned strains of Saccharomyces cerevisiae) capable of helping to prevent or treat plant diseases caused by pathogens, or capable of enhancing the effect of the aforementioned strains of Saccharomyces cerevisiae in preventing or treating plant diseases caused by pathogens.

According to one embodiment, the plant disease control composition of the present invention may contain these other active adjuvants.

According to another embodiment, these other active adjuvants may be administered to the plants individually, as an additional treatment (sequentially or alternatively).

These other relevant active adjuvants include in particular:

(1) any antagonistic microorganism different from the aforementioned strain of saccharomyces cerevisiae. Any known microorganism may be used as an antagonist, for example, of more than one plant pathogen.

Preferably, the antagonistic microorganism is selected from bacteria, fungi and yeast, preferably yeast.

The antagonistic micro-organism may be chosen in particular from: agrobacterium, Erysiphe, Aureobasidium, Bacillus, Bullessypium, Candida, Chaetomium, Cryptococcus, Debaryomyces, Dekkera, Erwinia, Exophiliaspp, Gliocladium, Hansenula, Issatchenkia, Kluyveromyces, Malaysia, Metschnikowia, Microdesmodium, Paecilomyces, Penicillium, Phlebiopsis pp. (ii) a Pichia, Pseudomonas, Candida, Pythium, Rhodotorula, Saccharomyces, Spinospora, Sporobolomyces, Streptomyces, Talaromyces, Trichoderma, Geobacillus, Verticillium, Zygosaccharomyces, and mixtures thereof; more specifically Agrobacterium radiobacter, Aureobasidium pullulans, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Candida oleophilic, Candida utilis, Candida sake, Candida tenuis, Candida utilis, Candida mycoderma, Chaetomium parvispora, Cryptococcus albidus, Cryptococcus laurentii, Cryptococcus flavescens, Erwinia carotovora, Gliocladium catenulatum, Gliocladium virens, Hansenula sporum, Kluyveromyces thermotolerans, Methchnikoviafaracofaracorucella, Metschnikoviavora, Microdochiumdimeum, Paecilomyces fumosoroseus, Penicillium oxalicum, Phanerochaete, Pichia anomala, Pichia guilliermondii, Pseudomonas cepacia, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pyrenophora tabacum, Pseudomonas pseudochinensis, Pseudomonas aeruginosa, Rhodotorula rubra, Rhodotorula glutinis, Saccharomyces cerevisiae, Streptomyces viridin, Streptomyces glaucopialus, Trichoderma polyspora, Trichoderma viride, Trichoderma asperellum, Trichoderma gamsii, Gekkera nigrescens, Verticillium alboatrum, and mixtures thereof.

(2) Calcium, potassium or sodium salts

Particularly effective salts as active adjuvants are described in detail in WO2006/032530, which is incorporated herein by reference.

In particular the hydrochloride, propionate, sulphate, phosphate, carbonate, bicarbonate, acetate, glycerate, glutamate, erythronate, threonate, gluconate, arabinonate, xylonate, lyxonate, allosate, altronate, gluconate, maleate, gulonate, idonate, hemi-lactobionate, talonate, trans-heptanoate, altoheptonate, glucoheptonate, mannoheptonate, glucoheptonate, idoheptonate, lactoheptonate, taloheptonate, tartronate, malate, tartrate, citrate, saccharate, mucate, lactate, lactogluconate (lactogluconate), ascorbate, iso-citrate and citramalate, preferably sodium or calcium or potassium (preferably calcium), whether they are in anhydrous or hydrated form.

Calcium lactate is particularly preferred. Mixtures of the above salts are also possible.

(3) A stimulant selected from the group consisting of uronic acids, mannan, beta-1, 3-glucan, mixtures and derivatives (salts, hydrates, etc.).

Among uronic acids, galacturonic acid and glucuronic acid are preferred.

(4) Fungicidal, antiviral and/or antibacterial agrochemicals.

The fungicidal substances may, for example, be chosen from organic agrochemical fungicides or inorganic fungicides based on sulphur and/or copper.

Examples of currently available organic agrochemical fungicides are, in particular, benzonitrile, including chlorothalonil, carbamates, including dithiocarbamates, such as mancozeb, phthalimides, including captan, sulfonamides, guanidines, quinones, quinolines, thiadiazines, anilides, hydroxyanilides, and phenylamides, imidazolinones, oxazolidinones, strobilurins, cyanoimidazoles, fluazinam, dinocap, silamepanid, p-dicarboximides, fludioxonil, organophosphates, propamocarb hydrochloride, diphenylamine, pyridylamines, sterol biosynthesis Inhibitors (IBS), including imidazoles, pyrimidines, hydroxypyrimidines, anilinopyrimidines, triazoles, spiroxamines, morpholines and piperidines, fenhexamid, hymexazol, zoxamide, fenhexamid, Diethofencarb, benzimidazoles, pencycuron, quinoxyfen, propineb, cymoxanil, dimethomorph, phosphonates and triazines.

The invention may also be used with more than one compound that causes a plant defense mechanism, such as beta-aminobutyric acid, 2, 6-dichloroisonicotinic acid, acibenzolar-S-methyl, or certain seaweed extracts, alternatively, in combination or in combination. Examples of such compounds are in particular laminarin and ulvans.

In this respect, the invention also provides a method for preventing or slowing the growth of a strain of fungi resistant to a type of fungicide, characterized in that the plants are treated with a strain of saccharomyces cerevisiae as described previously, with the aim of reducing the selective pressure of said strain resistant to said type of fungicide, as described above, or in that the treatment of the plants with said type of fungicide is alternated with or combined with the treatment of the plants with saccharomyces cerevisiae of the aforementioned strain, as described above.

The invention also provides a method for preventing or slowing the growth of a strain of bacteria resistant to a type of antibacterial agent, characterized in that said plant is treated with a strain of saccharomyces cerevisiae as described above with the aim of reducing the selection pressure of said strain resistant to said type of antibacterial agent, or in that the treatment of the plant with said antibacterial agent is alternated or combined with the treatment of the plant with saccharomyces cerevisiae of the aforementioned strain as described above.

However, according to a specific embodiment, the plant disease control composition of the present invention does not contain any fungicide, antiviral and/or antibacterial substances toxic to Saccharomyces cerevisiae. According to a particular embodiment, prior to the treatment with Saccharomyces cerevisiae of the aforementioned strains, no treatment with any fungicidal, antiviral and/or antibacterial agrochemical at toxic doses to Saccharomyces cerevisiae is employed, except for observations made during sufficient waiting times.

Examples

The following examples are intended to illustrate the invention without limiting it.

Example 1

The efficacy of the present invention against post-harvest fungal diseases was tested as follows.

Three lesions were made on each grapefruit. The plant disease control composition is applied to each lesion, allowed to dry, and then inoculated with a composition comprising a pathogen.

The pathogen used was Penicillium digitatum at a concentration of 5 × 10⁴Spores/ml.

After 4 or 5 days of incubation at 20 ℃, the mean diameter of the lesion was measured.

The following 4 plant disease controlling compositions containing various concentrations of microorganisms (obtained by serial dilution of a microbial culture in sterile distilled water) were used:

a: a composition comprising strain accession No. I-3936 deposited at french national collections of microorganisms (CNCMs) at 4.3.2008.

B: a composition comprising strain accession No. I-3937, deposited at french national collections of microorganisms ((CNCM)) on day 4/3 2008.

C: a composition comprising the strain of accession number I-3938 deposited at french national collections of microorganisms (CNCMs) at 4.3.2008.

D: a composition comprising strain accession No. I-3939, deposited at french national collections of microorganisms (CNCMs) at 4.3.2008.

The yeast strains are from LesafreInternational, France.

The pathogen is isolated from rotten grapefruit; storage on a glucose-potato agarose slant at 4 ℃; culturing in a glucose-potato agarose slant at 25 ℃; removing spores forming the edges of the spores after 2-3 weeks of culture; suspensions were made in sterile distilled water and spore concentrations were adjusted using a hemocytometer.

An average of more than 10 grapefruits were used per test.

The efficacy of the different prophylactic treatments was determined relative to the untreated control and the results are shown in table 1 below. The diameter of the lesion was measured on day 4, except for the results marked with an asterisk obtained on day 5.

TABLE 1 prevention of infection of grapefruit by Penicillium digitatum

Example 2

Except that apple was used instead of grapefruit and Botrytis cinerea (suspension of spores, concentration 10)⁶Spores/ml) and penicillium expansum (of a spore suspension, concentration 10)⁵Spores/ml) was used as the pathogen, and the same type of experiment as in example 1 was repeated. Lesions were assessed 6 days after inoculation and the results averaged for 15 fruits each time.

The results obtained for Botrytis cinerea are shown in tables 2a and 2b below, and the results against Penicillium expansum are shown in tables 3a and 3b below.

TABLE 2a prevention of infection of apple with Botrytis cinerea

TABLE 2b prevention of infection of apple with Botrytis cinerea

TABLE 3a prevention of infection of apple by Penicillium expansum

TABLE 3b prevention of infection of apple by Penicillium expansum

Example 3

The same type of experiment as in example 1 was repeated except that edible grapes were used instead of grapefruit and botrytis cinerea was used as the pathogen. Furthermore, the efficacy of yeast protection was determined by: the number of infected grape berries in each bunch of grapes was counted 7 days after inoculation with the pathogen in order to classify the bunch into 4 categories: (1) healthy grape bunch; (2) about 10% of the bunch is infected; (3) about 25% of the bunch is infected; (4) more than about 50% of the bunch is infected. The average damage value was calculated by assigning a score of 0 to the category (1), a score of 0.1 to the category (2), a score of 0.25 to the category (3), and a score of 0.6 to the category (4).

The results obtained for the undamaged grape bunch are shown in table 4 below, and the results obtained for the damaged grape bunch are shown in table 5 below.

TABLE 4 prevention of infection of undamaged grapes with Botrytis cinerea

TABLE 5 prevention of infection of impaired grapes by Botrytis cinerea

Example 4

This experiment was performed under actual conditions in the field and at the fruit packing station. In an orchard of nectarines of the species "Fantasia", 10 trees (including 5 untreated trees and 5 treated trees) were identified and numbered.

The dried yeast particles were dispersed in water at 20 ℃ by the instantaneous dispersion method to prepare a treatment mixture (ready-to-use plant disease-controlling composition) having a concentration of 25 g/L. The strain used to make these particles was strain a.

The fruit on the tree is treated before harvesting after the rotten fruit has been removed. After harvesting, the fruit trays are labeled with a tree number and placed in a freezer.

The fruits were kept at cold conditions (4 ℃) for one week and then at normal temperature (about 25 ℃) for 3 days to promote the development of diseases. And then scored. When lesions of glomus pratense or botrytis cinerea appear, the number and diameter (in mm) of lesions are recorded for each fruit observed.

Finally, the number of healthy fruits, the number of diseased fruits, the percentage of healthy fruits and diseased fruits, the average number of diseased spots per fruit, and the average diameter of diseased spots were calculated. Efficacy was calculated according to the Abott method based on the percentage of diseased fruit, the mean number of diseased spots and the mean diameter. The results are shown in table 6 below.

TABLE 6 effects on control of plant diseases at harvest conditions

Claims (17)

1. Saccharomyces cerevisiae strain selected from the group consisting of the strain deposited at CNCM at 3.4.2008, the strain deposited at CNCM at I-3938 at 3.4.2008, and the strain deposited at CNCM at I-3939 at 3.4.2008.

2. A composition for controlling plant diseases, characterized in that it comprises saccharomyces cerevisiae selected from the strain of accession No. I-3937 deposited at CNCM on day 3 and 4 of 2008, the strain of accession No. I-3938 deposited at CNCM on day 3 and 4 of 2008, and the strain of accession No. I-3939 deposited at CNCM on day 3 and 4 of 2008, and a mixture thereof.

3. The plant disease controlling composition according to claim 2, characterized in that it further comprises more than one formulation and/or at least one additional active adjuvant.

4. The plant disease controlling composition according to claim 2 or claim 3, characterized in that the plant disease controlling composition is a concentrated plant disease controlling composition which is a dry, solid or liquid formulation.

5. The plant disease controlling composition according to claim 2 or claim 3, characterized in that the plant disease controlling composition is a ready-to-use plant disease controlling composition in a dry or liquid formulation.

6. The plant disease controlling composition according to claim 5, wherein the plant disease controlling composition is contained at 10%⁴To 10¹¹An amount of between cfu/ml of Saccharomyces cerevisiae.

7. The plant disease controlling composition according to claim 6, wherein the plant disease controlling composition is contained at 10%⁵To 10¹⁰An amount of between cfu/ml of Saccharomyces cerevisiae.

8. The plant disease controlling composition according to claim 6, wherein the plant disease controlling composition is contained in 5 × 10⁵To 5 × 10⁹An amount of between cfu/ml of Saccharomyces cerevisiae.

9. A method for treating or protecting a plant against a disease caused by a fungus, said method comprising contacting said plant with saccharomyces cerevisiae selected from the group consisting of: the strain of accession number I-3937 deposited on CNCM at 4 d 3/2008, the strain of accession number I-3938 deposited on CNCM at 4 d 3/2008, and the strain of accession number I-3939 deposited on CNCM at 4 d 3/2008, and mixtures thereof, or contacting said plant with the composition for controlling plant diseases according to any one of claims 2 to 8.

10. The method according to claim 9, wherein the fungus is selected from the group consisting of fungi of the genera: alternaria, Chaetomium, Aspergillus, Botrytis, Aureobasidium, Cercospora, Cladosporium, anthrax, Cryptosporidium, Erysiphe, Fusarium, discospora, Sphaerotheca, Helminthosporium, Discospora, Pleurospora, Mycospora, Penicillium, Peronospora, Peziculaspp, Polychaetobacter, Phytophthora, Plasmopara, Sphaerotheca, Pseudocercospora, Pseudoperonospora, Puccinia, Pythium, Podospora, Rhizoctonia, Rhizopus, Rhinochloropsis, Sclerospora, Septoria, Monochaetomium, Neurospora, Exocladium, Sporotrichum, Uncaria, Ustilago, Venturia, and combinations thereof.

11. The method according to claim 10, wherein the fungus is selected from the group consisting of: alternaria solani, alternaria alternata, ascochyta nodella, aspergillus niger, aspergillus fumigatus, botrytis cinerea, colletotrichum lactucae, oxysporum graminearum, cladosporium cucumerinum, colletotrichum graminicolum, cryptosporidium humorum, aleuromyces graminis, fusarium oxysporum, fusarium roseum, levongosporium fructicola, gloeosporium viticola, helminthosporium graminum, rosewood spores, gloeosporium protuberans, gloeosporium brassicae, penicillium expansum, penicillium digitatum, peronospora parasitica, pezicula maliporticitis, phragmitis rubi-idaceae, phytophthora infestaphylum, plasmopara vitis, unispora leucotrichum, including cercospora brassicae, pseudoperonospora cubensis, pseudoperonospora medicaginis, phoma graminis, stylobacillus, rhizoctonia nigra, rhizopus, ryspora rosea, septoria, septori, Grape powdery mildew, wheat aleyrodids, apple scab, and combinations thereof.

12. The method according to claim 9, wherein the plant is selected from the group consisting of grasses, dicots, annual, semiannual and perennial plants, vegetable seedlings or harvested vegetables, fruit plants or harvested fruits, flower plants or harvested flowers, cereals, oil plants, protein producing plants, woody plants, and ornamental plants.

13. The method of claim 12, wherein the plant is selected from the group consisting of potato, beetroot, sugarcane, tobacco, vine, wheat, rapeseed, barley, rice, corn, sorghum, millet, beans, tomato, cucumber, lettuce, strawberry, apple, pear, citrus, banana, pineapple, peach, apricot, cherry, walnut, and hazel.

14. The method of claim 9, wherein the method comprises:

applying the ready-to-use plant disease control composition of claim 5 or 6 to the whole or part of the plant; or

Mixing the concentrated plant disease controlling composition according to claim 4 with a formulation to form a final plant disease controlling composition, and then applying the final plant disease controlling composition to the whole body or part of the plant.

15. The method according to claim 14, wherein the composition for controlling plant diseases is applied to the whole body or part of the plant, consisting of applying to leaves, stems, flowers, fruits, grains, seeds, trunks and/or roots or parts thereof.

16. The method of claim 15, wherein the applying is by spraying.

17. The method of claim 15, wherein the root is applied by ground spraying, mechanical blending, by mixing with a fertilizer, an enhancer, or as a premix.