The present invention provides methods of marker-assisted selection for high oleic/low linolenic traits in canola and in other oil seed crop species, as well as isolated nucleic acids for use as molecular markers in such methods. In particular, molecular markers and Brassica nucleic acid corresponding to fad2 and fad3 gene mutations are disclosed. The markers of the present invention are highly useful for the direct selection of desirable fad2 and fad3 alleles during marker-assisted trait introgression and breeding. In one aspect of the embodiment, two single nucleotide polymorphism (SNP) markers are provided that correspond to the alleles. Thus, the present invention advantageously permits one of skill in the art to breed for the molecular markers described herein, or derivatives thereof, rather than breeding for a high oleic/low linolenic phenotype.
1. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying one or more nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise a nucleotide sequence within a Fad2 gene that is capable of hybridizing to the nucleic acid molecule of SEQ ID NO:8 under high stringency conditions, but is not capable of hybridizing to the nucleic acid molecule of SEQ ID NO:7 under high stringency conditions;
crossing a Brassica plant comprising the identified one or more nucleic acid markers with another Brassica plant that does not comprise the identified one or more markers; and
selecting progeny from the cross that comprise the identified one or more nucleic acid markers.
2. The method of claim 1 , wherein Brassica is canola.
3. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying one or more nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise a nucleotide sequence within a Fad3 gene that is capable of hybridizing to the nucleic acid molecule of SEQ ID NO:12 under high stringency conditions, but is not capable of hybridizing to the nucleic acid molecule of SEQ ID NO:13 under high stringency conditions;
crossing a first Brassica plant comprising the identified one or more nucleic acid markers with a second Brassica plant that does not comprise the identified one or more markers; and
selecting progeny from the cross that comprise the identified one or more nucleic acid markers.
4. The method of claim 3 , wherein Brassica is canola.
5. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise
a nucleic acid marker comprising a nucleotide sequence within a Fad2 gene that is capable of hybridizing to the nucleic acid molecule of SEQ ID NO:8 under high stringency conditions, but is not capable of hybridizing to the nucleic acid molecule of SEQ ID NO:7 under high stringency conditions, and
a nucleic acid marker comprising a nucleotide sequence within a Fad3 gene that is capable of hybridizing to the nucleic acid molecule of SEQ ID NO:12 under high stringency conditions, but is not capable of hybridizing to the nucleic acid molecule of SEQ ID NO:13 under high stringency conditions;
crossing a Brassica plant comprising the identified markers with another Brassica plant that does not comprise the identified nucleic acid markers; and
selecting progeny from the cross that comprise the identified nucleic acid markers.
6. The method of claim 5 , wherein Brassica is canola.
7. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying one or more nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise SEQ ID NO:5;
crossing a first Brassica plant comprising the identified one or more nucleic acid markers with a second Brassica plant; and
selecting progeny from the cross that comprise the identified one or more nucleic acid markers.
8. The method according to claim 7 , wherein Brassica is canola.
9. The method according to claim 7 , wherein the one or more nucleic acid markers consist of a nucleic acid marker consisting of the polynucleotide of SEQ ID NO:5, wherein the presence of the nucleic acid marker consisting of the polynucleotide of SEQ ID NO:5 is determined in the first Brassica plant and the selected progeny by polymerase chain reaction, and wherein the Brassica plants are canola plants.
10. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying one or more nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise SEQ ID NO:6;
crossing a first Brassica plant comprising the identified one or more nucleic acid markers with a second Brassica plant, wherein the first Brassica plant comprises a G to A mutation at the first base of the 5′ splice site of the third intron in the Fad3 gene; and
selecting progeny from the cross that comprise the identified one or more nucleic acid markers.
11. The method according to claim 10 , wherein Brassica is canola.
12. The method according to claim 10 , wherein the one or more nucleic acid markers consist of a nucleic acid marker consisting of the polynucleotide of SEQ ID NO:6, wherein the presence of the nucleic acid marker consisting of the polynucleotide of SEQ ID NO:6 is determined in the first Brassica plant and the selected progeny by polymerase chain reaction, and wherein the Brassica plants are canola plants.
13. A method for reliably and predictably introgressing traits for high oleic and/or low linolenic acid content into Brassica germplasm, said method comprising:
identifying one or more nucleic acid markers that map to at least one of linkage groups N14, N4, N5 or N1, wherein the nucleic acid markers comprise
a first nucleic acid marker comprising SEQ ID NO:5 and
a second nucleic acid marker comprising SEQ ID NO:6;
crossing a first Brassica plant comprising the identified one or more nucleic acid markers with a second Brassica plant; and
selecting progeny from the cross that comprise the identified one or more nucleic acid markers.
14. The method according to claim 13 , wherein Brassica is canola.
15. The method according to claim 13 , wherein the one or more nucleic acid markers consist of two nucleic acid markers,
the first nucleic acid marker consisting of the polynucleotide of SEQ ID NO:5, and
the second nucleic acid marker consisting of the polynucleotide of SEQ ID NO:6,
wherein the presence of the two nucleic acid markers is determined in the first Brassica plant and the selected progeny by polymerase chain reaction, and wherein the Brassica plants are canola plants.