ALS INHIBITOR HERBICIDE TOLERANT BETA VULGARIS MUTANTS

1 . An ALS inhibitor herbicide tolerant Beta vulgaris plant and parts thereof comprising a mutation of an endogenous acetolactate synthase (ALS) gene, wherein the ALS gene encodes an ALS polypeptide containing an amino acid different from tryptophan at a position 569 of the ALS polypeptide.

2 . The Beta vulgaris plant and parts thereof according to claim 1 , in which the ALS polypeptide has at position 569 the amino acid alanine, glycine, isoleucine, leucine, methionine, phenylalanine, proline, valine, or arginine instead of the naturally encoded amino acid tryptophan.

3 . The Beta vulgaris plant and parts thereof according to claim 1 , wherein the ALS gene encodes an ALS polypeptide containing an amino acid different from tryptophan at a position 569 of the ALS polypeptide sequence as set forth in SEQ ID NO: 2.

4 . The Beta vulgaris plant and parts thereof according to claim 1 , in which the amino acid is leucine and in which the endogenous ALS gene is identical to the nucleotide sequence defined by SEQ ID NO: 3.

5 . The Beta vulgaris plant and parts thereof according to claim 1 , which are tolerant to one or more ALS-inhibitor herbicides belonging to the group consisting of sulfonylurea herbicides, sulfonylaminocarbonyltriazolinone herbicides, imidazolinone herbicides, triazolopyrimidine herbicides, and pyrimidinyl(thio)benzoate herbicides.

6 . The Beta vulgaris plant and parts thereof according to claim 1 , which are homozygous for the mutation of the endogenous acetolactate synthase (ALS) gene.

7 . The parts of the Beta vulgaris plant according to claim 1 , wherein the parts are organs, tissues, and cells of the plant, and preferably seeds.

8 . Method for the manufacture of the Beta vulgaris plant and the parts thereof of claim 1 , comprising the following steps:

(a) exposing calli from B. vulgaris , to about 10 −7 M-10 −9 M of an ALS inhibitor herbicide, preferably foramsulfuron;

(b) selecting cell colonies which can grow in the presence of up to 3×10 −6 M of an ALS inhibitor herbicide, preferably foramsulfuron;

(c) regenerating shoots in presence of an ALS inhibitor herbicide, preferably foramsulfuron;

(d) selecting regenerated plantlets with an ALS inhibitor herbicide, preferably foramsulfuron, iodosulfuron-methyl-sodium and/or a mixture of both, wherein the dose of foramsulfuron is preferably equivalent to 7-70 g a.i./ha and the dose of iodosulfuron-methyl-sodium is preferably equivalent to 1-10 g a.i./ha.