composition including a strain of Mitsuaria noduli

Abstract

The invention relates to a composition intended to improve plant growth comprising at least one strain of bacteria belonging to the species Mitsuaria noduli, preferably the Mitsuaria noduli strain filed with the CNCM on July 30, 2021 under No. I-5724 or I-5725; and the use of such a strain as a biostimulant.

Description

Title of the invention: Composition comprising a strain of Mitsuaria noduli Technical field

[0001] The present invention relates to the field of agriculture and, more specifically, to the use of a strain belonging to the species Mitsuaria nodulipour to improve plant growth. Previous art

[0002] In the agricultural sector, increasing production yields remains a major challenge, both economically and socially. To achieve this, numerous chemical and biological compositions have been proposed, leading to varying degrees of effectiveness. They aim to (i) directly control crop pests, (ii) protect plants from abiotic stress, (iii) stimulate natural defenses, and (iv) improve plant nutrition and growth. Description of the invention

[0003] The inventors have now found that, surprisingly, a particular species of Mitsuaria (i.e., Mitsuaria noduli) exerted significantly greater effects, in terms of plant growth and protection, compared to those obtained with other reference bacterial species.

[0004] The invention therefore aims to provide a new, highly effective composition to improve plant growth.

[0005] Accordingly, a first object of the invention relates to a composition intended to improve plant growth comprising at least one strain of bacteria belonging to the species Mitsuaria noduli.

[0006] Advantageously, this strain is the Mitsuaria noduli strain filed with the CNCM on July 30, 2021 under No. 1-5724 or 1-5725.

[0007] A second object of the invention relates to a method for increasing plant growth which includes a step of applying to the seed, the soil, the root or leaf part of the plant by spraying a composition such as described above.

[0008] Advantageously, the method according to the invention aims to increase plant growth under water stress.

[0009] Typically, this improvement could take the form of:

[0010] 1) the improvement of yield for rapeseed, strawberry or basil.

[0011] 2) the improvement of the nutrition of the strawberry plant.

[0012] 3) the improvement of sunflower flowering.

[0013] 4) the improvement of rapeseed rooting.

[0014] A third object of the invention relates to the use of a bacterial strain belonging to the species Mitsuaria noduli as a biostimulant.

[0015] Advantageously, said biostimulant is a water-stress biostimulant.

[0016] Typically, this biostimulant aims to:

[0017] 1) improve the yield for rapeseed, strawberry or basil.

[0018] 2) improve the nutrition of the strawberry plant.

[0019] 3) improve sunflower flowering.

[0020] 4) improve rapeseed rooting.

[0021] A fourth object of the invention relates to the CNCM 1-5724 and CNCM 1-5725 strains Detailed description

[0022] The composition according to the invention typically comprises 104 to 1012 CFU / g or CFU / ml, in particular 105 to 1010 CFU / g or CFU / ml, preferably 106 to 108 CFU / g or CFU / ml of Mitsuaria noduli.

[0023] In terms of weight, the composition according to the invention may comprise from 0.005 to 4% by weight (relative to the total weight of the composition) of Mitsuaria noduli, preferably from 0.1 to 3% by weight (relative to the total weight of the composition) of Mitsuaria noduli.

[0024] The composition according to the invention may take one of the multiple forms suitable for use as a biostimulant such as solid forms (e.g. powders, in particular wettable powders, or granules, in particular micro-granules), liquids (e.g. suspensions) or gels.

[0025] The Mitsuaria noduli strain is advantageously in live form. Optionally, extracts of said strain may be used.

[0026] By biostimulant, we mean. Also, and in the sense of the present invention; the term biostimulant encompasses that of fertilizer.

[0027] The composition according to the invention may include at least one support acceptable in agriculture.

[0028] Such supports are well known and include in particular talc, chalk, maltodextrin, glucose, kaolin, diatomaceous earth, chitin, alginates or carrageenan.

[0029] The composition according to the invention may include at least one other active agent.

[0030] In one embodiment, the composition of the invention is characterized in that it comprises at least said strain of bacteria in combination with other microorganisms (yeasts, bacteria and / or fungi) that are live, inactivated or in the form of extracts.

[0031] In another embodiment of the invention, the composition will further comprise, and advantageously, microorganisms, living or inactivated, extracts of microorganisms, fertilizers, herbicides, insecticides, fungicides, mineral solutions and / or culture media.

[0032] The invention also relates to formulations of the composition for soil treatment, root treatment, foliar treatment and / or seed treatment.

[0033] In the context of improving plant growth, the composition according to the invention can be applied repeatedly, for example every 3 to 6 weeks, preferably on the seed or at the time of emergence, at the early stages of flowering, appear favorable to the development of the plant and increase its growth.

[0034] The application of the composition defined above to cereal crops (wheat, barley, oats, rye), root crops (sugar beet, potato, corn), legumes (alfalfa, clover, sainfoin), grasses (ryegrass, fescue, orchard grass), oilseed and protein crops (soybean, rapeseed, pea, broad bean, white lupin), vegetable and market garden crops, fruit tree cultivation, viticulture and ornamental crops (flower production, nurseries of young plants) are of particular interest.

[0035] Other features and advantages of the invention are given, by way of illustration, in the following examples and in the single Figure which shows the results of a test on tomato plants in a growth chamber. Examples

[0036] 1) Improvement of strawberry plant yield and nutrition induced by Mistuaria noduli

[0037] The strawberry plants used were of the ciflorette variety, which were planted in 9 trays containing 4.3 kg of THREL (FLORANTAISE) potting soil.

[0038] An inoculum comprising the strain Mistuaria noduli Bio T025 (CNCM-° 1-5724) or the strain Pae n ibacillus polymixa CT43 is introduced into 3 trays at a rate of 3 x 10⁹ CFU / liter of potting soil. The 3 remaining trays are not inoculated and serve as controls.

[0039] Yield, number of fruits, their weight, and their quality are determined at the end of the growing season. Simultaneously, the efficiency of nutrient use in the soil is determined by establishing their respective concentrations before and after cultivation. The results are presented in Table I below.

[0040] Table I Indicators: Mistuaria noduliBïo T0 25 ( / control) Pae n ibacillus polymixa CT43 ( / control) Yield (%) +17.6 +24.3 Number of fruits (%) +14.3 +17.9 Fruit weight (%) +8.3 +16.6 Brix percentage +25.1 Nitrogen use efficiency (%) +89.7 +61.22 Magnesium use efficiency (%) +88.8 +66.6 Potassium use efficiency (%) +82.6 +26 Phosphorus use efficiency (%) +85.7 +57.51

[0041] The results demonstrate that both tested strains have an effect on yield, with a parallel increase in the number of fruits. While a simultaneous increase in plant nutrition is observed, this increase is particularly pronounced with the inoculum of the Mistuaria noduli Bio T025 strain. It should be noted that a slight improvement in fruit quality (Brix percentage) is observed with the Mistuaria noduli Bio T025 strain, whereas a more marked decrease is observed with the Paenibacillus polymixa CT43 strain.

[0042] 2) Improvement of plant yield, particularly under water stress basil induced by Mistuaria noduli

[0043] The basil seeds (Basilicum genovese) used were of the variety Eleonora ENZA ZADEN).

[0044] The seeds were planted in a germination potting mix composed of coconut fiber, peat, and perlite (FLORENTAISE), and an inoculum comprising the strain Paraburkolderia graminis Bio Tl 19, the strain Mistuaria noduli Bio T025 (CNCM-1-5724), or the strain Pae n ibacillus polymixa CT43 was introduced per tray at a rate of 1.5 x 10⁹ CFU / liter of germination potting mix. A second inoculation was then carried out with the different strains as soon as the cotyledons of the basil plants had emerged. This inoculation was performed by subirrigation and aimed to ensure homogeneous colonization of the bacteria around the roots (inoculation dose: 1.5 x 10⁹ CFU / liter of potting mix). The three controls were not inoculated.

[0045] On the day of transplanting, the percentage of germination is determined for each of the conditions. The results are given in Table II below.

[0046] Table II Inoculum % germination - 89.6 Paraburkolderia graminis Bio Tl 19 100.0 Mistuaria noduliBïo T025 95.1 Pae n ibacillus polymixa CT43 98.6

[0047] The results show that each of the bacterial strains improves germination.

[0048] The plants are then transplanted into 20 trays containing 3.6 kg of THREL (Florentaise) potting soil, with 14 plugs per tray, each plug containing 2 basil plants.

[0049] An inoculum comprising the strain Paraburkolderia graminis Bio Tl 19, the strain Mistuaria noduli Bio T025 (CNCM-1-5724), or the strain Pae n ibacillus polymixa CT43 is introduced into four trays at a rate of 3 x 10⁹ CFU / liter of potting soil, onto plants that have been previously inoculated with the same strain. The four remaining trays are not inoculated and serve as controls.

[0050] Two distinct water regimes are applied, each to two tanks inoculated with a specific bacterial strain and to two control tanks, with:

[0051] - a control modality where 100% of evapotranspiration is replenished per day

[0052] - a water stress modality (ETP 65) where only 65% ​​of evapotranspiration is filled per day.

[0053] The basil plants are cut several times (about once every 10-12 days) before the final harvest at the end of the growing season.

[0054] The yield is then determined, which is calculated in relation to the weight of dry matter per cell (g / cell). The results are presented in Table III below.

[0055] Table III Inoculum Yield under normal conditions (% compared to control) Yield under water stress conditions at 65% of ETP (% compared to control) Paraburkolderia gramis Bio Tl 19 + 12.58 +13.90 Mistuaria noduli Bio T0 25 + 14.92 +32.39 Paenibacillus polymix a CT43 + 15.52 +31.12

[0056] The results demonstrate that the three strains tested have an effect on yield. Now, the inocula of Mistuaria noduli Bio T025 and Pae n ibacillus polymixa CT43 allow for the maintenance of a much better yield in the presence of water stress.

[0057] 3) Improvement of rapeseed plant yield induced by Mistuaria noduli

[0058] Sensation winter rapeseed seeds (SEMENCES DE FRANCE) are placed in a pot (500 ml) containing clay soil (dominated by sunflower and rapeseed).

[0059] For each seedling, a sprinkling of 0.5 ml of solution is carried out, containing or not an inoculum of 109 CFU / ml of the strain Paraburkolderia graminis Bio Tl 19, the strain Mistuaria noduli Bio T025 (CNCM-1-5724), or the strain Mistuaria noduliBio T027 (CNCM-I5725).

[0060] The culture is then carried out in a greenhouse for 8 weeks. At the end of this period, the aboveground dry matter and root dry matter are determined for each plant. The results are presented in Table IV.

[0061] Table IV Inoculum Aerial dry matter (%) Root dry matter (%) - 100 100 Paraburkolderia graminis Bio Tl 19 121.05 121.04 Mistuaria noduliBio T025 136.8 105.26 Mistuaria noduliBio T027 194.7 178.94

[0062] The results demonstrate that the three strains tested have an effect on yield. Now, the Mistuaria noduli Bio T027 inoculum allows for a very significant improvement in yield, which improvement is accompanied by better rooting.

[0063] 4) Improvement of sunflower plant flowering under water stress induced by Mistuaria noduli

[0064] Naturela variety sunflower seeds (CAUSSADE SEMENCES) are coated or uncoated at a rate of 105 CFU / seed of the strain Paraburkolderia graminis Bio Tl 19 or of the strain Mistuaria noduliBio T025 (CNCM-1-5724).

[0065] These seeds are then planted in micro-plots in Charente during periods of water stress over a period of 5 months.

[0066] Flowering is determined at harvest and the results are presented in Table V below.

[0067] Table V Inoculum Flowering Homogeneity - 6.5 Paraburkolderia graminis Bio Tl 19 8.5 Mistuaria noduli Bio T025 7.3

[0068] As a preliminary point, it should be noted that rainy periods occurred in August. These periods allowed for a significant recovery in flowering for the control. Despite this recovery, the results demonstrate that both tested strains have an effect on flowering. Furthermore, the Mistuaria noduliBio T025 inoculum significantly improves flowering.

Claims

Demands

1. A method for increasing plant growth under water stress comprising an application step on the seed, soil, root or leaf part of the plant by spraying a composition comprising at least one live bacterial strain characterized in that said live bacterial strain: - increases plant growth under water stress, and - belongs to the species Mitsuaria noduli.

2. The method according to claim 1, characterized in that said strain is the Mitsuaria nodulidé strain filed with the CNCM on July 30, 2021 under No. 1-5724 or 1-5725.

3. The method according to any one of claims 1 or 2, characterized in that the composition typically comprises 104 to 1012 CFU / g or CFU / ml of Mitsuaria noduli.

4. The method according to any one of claims 1 to 3, characterized in that it aims to improve the yield of rapeseed, strawberry or basil.

5. The method according to any one of claims 1 to 3, characterized in that it aims to improve the nutrition of the strawberry plant.

6. A use of a live bacterial strain belonging to the species Mitsuaria noduli as a biostimulant under water stress, characterized in that said live bacterial strain: - increases plant growth under water stress, and - belongs to the species Mitsuaria noduli.

7. The use according to claim 6, characterized in that said strain is the Mitsuaria nodulidé strain filed with the CNCM on July 30, 2021 under No. 1-5724 or 1-5725.

8. A strain of Mitsuaria nodulidé filed with the CNCM on July 30, 2021 under No. 1-5724 or 1-5725.

9. A composition intended to improve plant growth comprising at least one strain as defined in claim 8.