Location: Sunflower and Plant Biology ResearchTitle: Molecular mapping of three nuclear male sterility mutant genes in cultivated sunflower (Helianthus annuus L.) Author
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2014
Publication Date: 6/1/2014
Citation: Gong, L., Li, C., Capatana, A., Feng, J., Qi, L., Seiler, G.J., Jan, C.C. 2014. Molecular mapping of three nuclear male sterility mutant genes in cultivated sunflower (Helianthus annuus L.). Molecular Breeding. 34:159-166. Interpretive Summary: The global production of sunflower is dependent on a single female parent, PET1, derived from a wild sunflower some 45 years ago. Needless to say, reliance on a single cytoplasmic male sterile source for hybrid sunflower production may prove to be disastrous, as was experienced by the epidemic of southern corn leaf blight in corn in the early 1970s. The need for more diversified female parent(s) in sunflower has led to the search for new male sterile sources. Male sterility can appear spontaneously or can be chemically induced via mutation in nuclear or cytoplasmic genes. Three previously produced nuclear male sterile lines with genes ms6, ms7, and ms8 controlled by single recessive genes were developed using chemical mutation. Genetic markers have not been identified to map these genes on the sunflower map to better diversify the sunflower base and utilize these sources. The objectives of this study were to map the three nuclear male sterile genes using genetic markers and place them on sunflower map to facilitate the utilization of the genes for sunflower breeding through molecular marker-assisted selection, and to improve breeding efficiency by eliminating emasculation. A partial linkage map consisting of eight markers was constructed for the ms6 gene. Six markers were identified for ms7, while ten markers were identified for the ms8 gene. The markers and mapping information will be useful for selection of the recessive nuclear male sterility genes in marker-assisted selection to improve efficiency in breeding programs and to broaden the genetic base of cultivated sunflower.
Technical Abstract: The nuclear male sterility (NMS) trait is a useful tool for sunflower (Helianthus annuus L.) breeding and genetic programs. Previously, we induced NMS mutants in cultivated line HA 89. The mutants possessed single recessive genes, ms6, ms7, and ms8, respectively, in NMS HA 89-872, NMS HA 89-552, and NMS HA 89-747. Bulked segregant analysis based on the male-fertile and male-sterile DNA pools and 560 SSR and In Del markers randomly selected from 17 linkage groups (LG) was used to locate ms6 to LG 16, ms7 to LG 6, and ms8 to LG 5. Subsequent genotypings of three F2 populations of 88, 93, and 76 individuals confirmed their map positions. Additional polymorphic markers derived from four RFLP-converted STS primer pairs were identified. A partial linkage map consisting of eight markers was constructed for the ms6 locus, covering a region of 69.24 cM, with markers ORS807 and ORS996 flanking the ms6 locus at the distances of 7.2 cM and 18.5 cM, respectively. Six markers were constructed for ms7 covering a region of 53.4 cM, with ORS608 and ORS1229 flanking the ms7 at a distance of 2.6 and 9.5 cM, respectively. Ten markers were constructed for ms8 covering a region of 18.0 cM, with six markers below ms8 and CRT518 above flanking the ms8 at a distance of 7.4 and 3.8 cM, respectively. The markers and mapping information will be useful for selection of the recessive NMS genes in sunflower breeding programs.