Molecular mapping of three nuclear male sterility mutant genes in cultivated sunflower (Helianthus annuus L.)

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 ms (6), ms (7), and ms (8), 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 simple sequence repeat and insertion/deletion markers randomly selected from 17 linkage groups (LGs) were used to locate ms (6) to LG16, ms (7) to LG6, and ms (8) to LG5. Subsequent genotyping of three F2 populations of 88, 93, and 76 individuals confirmed their map positions. Additional polymorphic markers derived from four restriction fragment length polymorphism-converted sequence-tagged site primer pairs were identified. A partial linkage map consisting of eight markers was constructed for the ms (6) locus, covering a region of 69.24 cM, with markers ORS807 and ORS996 flanking the ms (6) locus at distances of 7.2 and 18.5 cM, respectively. Six markers were constructed for ms (7), covering a region of 53.4 cM, with ORS608 and ORS1229 flanking ms (7) at distances of 2.6 and 9.5 cM, respectively. Ten markers were constructed for ms (8), covering a region of 18.0 cM, with six markers below ms (8) and CRT518 above flanking ms (8) at distances 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.