Gene Cloning and Characterization - Genetics, Genomics and Breeding of Crop Plants - page 209

Es 3 gene to LG 8 of the sunflower genetic map. The nuclear male sterility
gene Ms 11 gene was also mapped to LG 8. The genetic distance between this
gene and Es 3 was found to be 7.4 cM. Reliable codominant markers linked
to Es 3 have been identified (Pérez-Vich et al. 2006b). These markers can be
used to distinguish the heterozygote Es 3/ es 3 from the Es 3/ Es 3 in a backcross
program without the need for progeny testing. The Es 3 gene is an important
target for marker-assisted breeding programs because its expression is
strongly influenced by temperature during seed maturation (Fernández-
Moya et al. 2002, 2003).
An additional sunflower mutant, CAS-12, was obtained by X-irradiation
of the high-oleic line BDS-2-432, which has both high palmitic (about 30%)
and high oleic acid contents, and also substantial amount (about 7%) of
palmitoleic acid (Fernández-Martínez et al. 1997). Venegas-Caleron et al.
(2008) described a new half-palmitic mutant line, CAS-7, with about 14%
palmitic acid content that was obtained by chemical mutagenesis using
sodium azide. This mutant is also called wrinkled because the cotyledons
show a characteristic wrinkled phenotype. The homozygous line is lethal
within 10-12 days after germination, so the line can only be maintained as
a heterozygous. The triacylglycerol content showed a reduction of 57%
compared to the control. Furthermore, this mutant has 40% of trilinolein,
the highest content found till today in sunflower seeds. The cause of this
mutation that gave multiple changes in the phenotype including poor green
color and reduced chloroplast development is still unknown.
6.4.3.2 Mutants in Developmental Processes
Giordani et al. (1999) studied expression of the dehydrin gene, HaDhn1a in
two sunflower mutants for ABA synthesis and accumulation: nd-1 tan albino,
which is a nondormant and lethal mutant with a very low ABA content and
no ABA accumulation in response to stress and w-1, a wilty mutant with
reduced ABA accumulation during embryo and plantlet development. The
results indicated the existence of two regulation pathways of HaDhn1a
transcript accumulation, an ABA-dependent and an ABA-independent one,
which may have cumulative effects (Giordani et al. 1999).
Fambrini et al. (2003) described a spontaneous mutant of sunflower,
named missing flower ( mf ), which was found among progenies of the inbred
line Double Petal Whorl ( DPW ), previously selected from an in vitro-derived
progeny (Barotti et al. 1995). The DPW genotype is characterized by a homeotic
substitution of the anther whorl with chimeric structures mixed with anther
and petal tissue (Barotti et al. 1995). The mutant missing flower ( mf ) is
characterized by a lack of axillary shoots. The phenotype is the result of a
defect in axillary meristem initiation. In addition to shoot branching, the
mutation affects floral differentiation. The gene product of missing flower seems