Disease resistant watermelon plants
The present invention relates to novel watermelon plants displaying an increased resistance to Fusarium oxysporum f. sp. niveum race 2 infection. The present invention also relates to seeds and parts of said plants, for example fruits. The present invention further relates to methods of making and using such seeds and plants. The present invention also relates to novel genetic sequences associated with said increased resistance and to molecular markers associated with said novel genetic sequences.
1 . A cultivated Citrullus lanatus subsp. lanatus plant resistant to Fusarium oxysporum f. sp. niveum race 1,2 (FON 2) infection, comprising in its genome an introgressed sequence from Citrullus lanatus subsp. citroides which confers resistance to FON 2, wherein said introgressed sequence is comprised in Citrullus lanatus subsp. citroides accession RCAT055816 or in watermelon plant 18WMH505078, representative seed of which is deposited under NCIMB Accession No. 43627, and wherein said introgressed sequence is located on chromosome 10 and comprises at least the following SNP markers:
a) an A genotype in the heterozygous or homozygous state for SNP marker 7 at a position corresponding to position 66 in SEQ ID NO: 31; and
b) an A genotype in the heterozygous or homozygous state for SNP marker 10 at a position corresponding to position 64 in SEQ ID NO: 46.
2 . The plant according to claim 1 , wherein:
a)
the A genotype for SNP marker 7 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 32 and reverse primer of SEQ ID NO: 35, and probe of SEQ ID NO: 33; and
b) the A genotype for SNP marker 10 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers:
forward primer of SEQ ID NO: 47 and reverse primer of SEQ ID NO: 50, and probe of SEQ ID NO: 48.
3 . The plant according to claim 1 , wherein said introgressed sequence comprises at least one of SEQ ID NO: 31 or SEQ ID NO: 46, or a sequence that is at least 80% identical to one or both of said sequences.
4 . The plant according to claim 1 , wherein said plant is homozygous for at least one of SNP marker 7 or SNP marker 10.
5 . The plant of claim 1 , wherein said plant is obtained by crossing Citrullus lanatus subsp. citroides accession RCAT055816 or watermelon plant 18WMH505078, representative seed of which is deposited under NCIMB Accession No. 43627, or a progeny or an ancestor thereof, with a watermelon plant that does not contain said FON 2 resistance-conferring introgressed sequence.
6 . The plant of claim 1 , wherein said plant is an inbred, a dihaploid, a diploid, a triploid, a tetraploid or a hybrid plant.
7 . A plant of watermelon plant 18WMH505078, representative seed of which is deposited under NCIMB Accession No. 43627.
8 . A plant part of a plant according to claim 1 .
9 . A seed that produces a plant according to claim 1 or claim 7 .
10 . A method for producing a cultivated watermelon plant, exhibiting resistance to FON 2 comprising the steps of
a) crossing a plant according to claim 1 with a cultivated watermelon plant lacking said FON 2 resistance-conferring introgressed sequence;
b) selecting a progeny plant comprising said introgressed sequence located on chromosome 10 conferring resistance to FON 2, said selecting step comprising detecting at least one of the following SNP markers:
i)
an A genotype in the heterozygous or homozygous state for SNP marker 7 at a position corresponding to position 66 in SEQ ID NO: 31; and
ii) an A genotype in the heterozygous or homozygous state for SNP marker 10 at a position corresponding to position 64 in SEQ ID NO: 46;
thereby producing a plant with enhanced resistance to FON 2.
11 . The method according to claim 10 , wherein the method further comprises:
c) selfing the selected progeny or crossing the selected progeny with another watermelon plant to produce further progeny.
12 . The method according to claim 11 , wherein further progeny are selected and selfed/crossed for 2 to 10 more generations.
13 . A method for producing a F1 watermelon plant exhibiting resistance to FON 2, the method comprising crossing an inbred watermelon plant, which is a plant according to claim 1 , with a different inbred watermelon plant to produce F1 hybrid progeny.
14 . A method of producing watermelon seed, the method comprising growing a plant from the seed of claim 9 , and allowing the plant to produce further seed.
15 . The plant according to claim 1 , wherein said introgressed sequence comprises at least one of the following SNP markers:
c) a G genotype in the heterozygous or homozygous state for SNP marker 1 at a position corresponding to position 129 in SEQ ID NO: 1;
d) an A genotype in the heterozygous or homozygous state for SNP marker 2 at a position corresponding to position 120 in SEQ ID NO: 6;
e) an indel genotype in the heterozygous or homozygous state for SNP marker 3 at a position corresponding to position 164 in SEQ ID NO: 11;
f) an A genotype in the heterozygous or homozygous state for SNP marker 4 at a position corresponding to position 51 in SEQ ID NO: 16;
g) an A genotype in the heterozygous or homozygous state for SNP marker 5 at a position corresponding to position 93 in SEQ ID NO: 21;
h) a C genotype in the heterozygous or homozygous state for SNP marker 6 at a position corresponding to position 135 in SEQ ID NO: 26;
i) an A genotype in the heterozygous or homozygous state for SNP marker 8 at a position corresponding to position 61 in SEQ ID NO: 36;
j) a G genotype in the heterozygous or homozygous state for SNP marker 9 at a position corresponding to position 83 in SEQ ID NO: 41;
k) an A genotype in the heterozygous or homozygous state for SNP marker 11 at a position corresponding to position 93 in SEQ ID NO: 51;
l) an A genotype in the heterozygous or homozygous state for SNP marker 12 at a position corresponding to position 83 in SEQ ID NO: 56;
m) a G genotype in the heterozygous or homozygous state for SNP marker 13 at a position corresponding to position 138 in SEQ ID NO: 61;
n) a G genotype in the heterozygous or homozygous state for SNP marker 14 at a position corresponding to position 69 in SEQ ID NO: 66; and/or
o) an A genotype in the heterozygous or homozygous state for SNP marker 15 at a position corresponding to position 51 in SEQ ID NO: 71.
16 . The plant according to claim 1 , wherein:
c) the G genotype for SNP marker 1 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 2 and reverse primer of SEQ ID NO: 5, and probe of SEQ ID NO: 3;
d) the A genotype for SNP marker 2 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 7 and reverse primer of SEQ ID NO: 10, and probe of SEQ ID NO: 8;
e) the indel genotype for SNP marker 3 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 12 and reverse primer of SEQ ID NO: 15, and probe of SEQ ID NO: 13;
f) the A genotype for SNP marker 4 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 17 and reverse primer of SEQ ID NO: 20, and probe of SEQ ID NO: 18;
g) the A genotype for SNP marker 5 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 22 and reverse primer of SEQ ID NO: 25, and probe of SEQ ID NO: 23;
h) the C genotype for SNP marker 6 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 27 and reverse primer of SEQ ID NO: 30, and probe of SEQ ID NO: 28;
i) the A genotype for SNP marker 8 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 37 and reverse primer of SEQ ID NO: 40, and probe of SEQ ID NO: 38;
j) the G genotype for SNP marker 9 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 42 and reverse primer of SEQ ID NO: 45, and probe of SEQ ID NO: 43;
k) the A genotype for SNP marker 11 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 52 and reverse primer of SEQ ID NO: 55, and probe of SEQ ID NO: 53;
l) the A genotype for SNP marker 12 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 57 and reverse primer of SEQ ID NO: 60, and probe of SEQ ID NO: 58;
m) the G genotype for SNP marker 13 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 62 and reverse primer of SEQ ID NO: 65, and probe of SEQ ID NO: 63;
n) the G genotype for SNP marker 14 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 67 and reverse primer of SEQ ID NO: 70, and probe of SEQ ID NO: 68; and/or
o) the A genotype for SNP marker 15 can be identified in a PCR by amplification of a nucleic acid fragment with a pair of oligonucleotide primers: forward primer of SEQ ID NO: 72 and reverse primer of SEQ ID NO: 75, and probe of SEQ ID NO: 73.
17 . The plant according to claim 1 , wherein said introgressed sequence comprises at least one of SEQ ID NO: 1, SEQ ID NO: 6, SEQ ID NO: 11, SEQ ID NO: 16, SEQ ID NO: 21, SEQ ID NO: 26, SEQ ID NO: 36, SEQ ID NO: 41, SEQ ID NO: 51, SEQ ID NO: 56, SEQ ID NO: 61, SEQ ID NO: 66, and/or SEQ ID NO: 71, or a sequence that is at least 80% identical to one or more of said sequences.
18 . The method according to claim 10 , wherein said selecting step of (b) further comprises detecting at least one of the following SNP markers:
iii) a G genotype in the heterozygous or homozygous state for SNP marker 1 at a position corresponding to position 129 in SEQ ID NO: 1;
iv) an A genotype in the heterozygous or homozygous state for SNP marker 2 at a position corresponding to position 120 in SEQ ID NO: 6;
v) an indel genotype in the heterozygous or homozygous state for SNP marker 3 at a position corresponding to position 164 in SEQ ID NO: 11;
vi) an A genotype in the heterozygous or homozygous state for SNP marker 4 at a position corresponding to position 51 in SEQ ID NO: 16;
vii) an A genotype in the heterozygous or homozygous state for SNP marker 5 at a position corresponding to position 93 in SEQ ID NO: 21;
viii) a C genotype in the heterozygous or homozygous state for SNP marker 6 at a position corresponding to position 135 in SEQ ID NO: 26;
ix) an A genotype in the heterozygous or homozygous state for SNP marker 8 at a position corresponding to position 61 in SEQ ID NO: 36;
x) a G genotype in the heterozygous or homozygous state for SNP marker 9 at a position corresponding to position 83 in SEQ ID NO: 41;
xi) an A genotype in the heterozygous or homozygous state for SNP marker 11 at a position corresponding to position 93 in SEQ ID NO: 51;
xii) an A genotype in the heterozygous or homozygous state for SNP marker 12 at a position corresponding to position 83 in SEQ ID NO: 56;
xiii) a G genotype in the heterozygous or homozygous state for SNP marker 13 at a position corresponding to position 138 in SEQ ID NO: 61;
xiv) a G genotype in the heterozygous or homozygous state for SNP marker 14 at a position corresponding to position 69 in SEQ ID NO: 66; and/or
xv) an A genotype in the heterozygous or homozygous state for SNP marker 15 at a position corresponding to position 51 in SEQ ID NO: 71.
19 . The method according to claim 10 , wherein the cultivated watermelon plant is a cultivated Citrullus lanatus subsp. lanatus plant.