Biological control of pythium disease in crops
Strains of Rhizobium leguminosarum biovar viceae have antifungal activity against the pathogen Pythium ultimum . Compositions and methods for treating or protecting plants susceptible to Pythium ultimum damage, and Pythium sp. “group G” damage in particular, are provided. Such strains include, for example, the strains deposited in the International Depository Authority of Canada under accession numbers IDAC 200704-01, IDAC 200704-02, IDAC 200704-03, and IDAC 200704-04.
1 . A method for treating or protecting a plant susceptible to Pythium ultimum comprising contacting the plant or part thereof, or the soil surrounding the plant, with an effective amount of at least one Rhizobium leguminosarum biovar viceae strain which has suppressive activity against Pythium ultimum.
2 . The method according to claim 1 wherein the at least one Rhizobium leguminosarum biovar viceae strain which has suppressive activity against Pythium sp. “group G”.
3 . The method according to claim 1 wherein the plant is in the form of a seed.
4 . The method according to claim 1 wherein the plant part contacted comprises root.
5 . The method according to claim 1 wherein the plant is selected from the group consisting of sugar beet, field pea, lentil, safflower, canola, chickpea, sunflower, alfalfa, soybean and field bean.
6 . The method according to claim 1 wherein the plant is treated or protected from seed rot or damping-off.
7 . The composition according to claim 2 wherein the strain inhibits the colonization of Pythium sp. “group G” on an agar plate.
8 . The method according to claim 1 wherein the bacteria comprises the bacterium deposited under International Depository Authority of Canada Accession number IDAC 200704-01.
9 . The method according to claim 1 wherein the bacteria comprises the bacterium deposited under International Depository Authority of Canada Accession number IDAC 200704-02.
10 . The method according to claim 1 wherein the bacteria comprises the bacterium deposited under International Depository Authority of Canada Accession number IDAC 200704-03.
11 . The method according to claim 1 wherein the bacteria comprises the bacterium deposited under International Depository Authority of Canada Accession number IDAC 200704-04.
12 . The isolated Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-01.
13 . The isolated Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-02.
14 . The isolated Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-03.
15 . The isolated Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-04.
16 . An antifungal composition comprising bacteria of at least one isolated Rhizobium leguminosarum biovar viceae strain which has suppressive activity against Pythium ultimum.
17 . The composition according to claim 16 wherein the at least one Rhizobium leguminosarum biovar viceae strain has suppressive activity against Pythium sp. “group G”.
18 . The composition according to claim 17 wherein the strain inhibits the colonization of Pythium sp. “group G” on an agar plate.
19 . The composition according to claim 16 comprising one or more biologically inert components.
20 . The composition according to claim 19 wherein the one or more inert component is selected from the group consisting of carrier materials, stickers, binders, adhesives, extenders, and mixtures thereof.
21 . The composition according to claim 19 comprising cells or spores of other biological control agents, one or more chemical fungicides, or one or more pesticides.
22 . The composition according to claim 16 wherein the bacteria strain is the Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-01.
23 . The composition according to claim 16 wherein the bacteria strain is the Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-02.
24 . The composition according to claim 16 wherein the bacteria strain is the Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-03.
25 . The composition according to claim 16 wherein the bacteria strain is the Rhizobium leguminosarum biovar viceae strain deposited under International Depository Authority of Canada Accession number IDAC 200704-04.