International Journal of Horticulture, 2015, Vol.5, No.21, 1-45
24
consistent event. Park et al. (2009) used two molecular techniques, RAPD and methylationsensitive amplification
polymorphism (MSAP) analyses to characterize the somaclones. Their study demonstrated usefulness of MSAP to
detect DNAmethylation events in tissue cultured
Doritaenopsis
plants.
Gentian is one of the most important ornamental flowers in Japan and cultivars are easily proliferated vegetatively.
Shimada et al. (2008) attempted to develop a reliable discrimination method to prevent the illegal propagation and
distribution of various high-value cultivars. They used five (SCAR markers based on the length polymorphisms in
introns of four gentian flavonoid biosynthetic genes. These SCAR markers effectively discriminated nine gentian
cultivars and nine breeding lines. This method could be applied in identifying gentian cultivars/lines and therefore
will aid in protecting breeders’ rights.
Dallavalle et al. (2002) applied RAPD experiments and isolated the specific band in
Gladiolus
for different
sensitivities to
Fusarium oxysporum
Schlecht.
Bhatia et al. (2009) used 32 ISSR markers to study the genetic fidelity of
in vitro
raised 45 plants of gerbera
(
Gerbera jamesonii
Bolus) derived from three different explants,
viz.
, capitulum, leaf and shoot tips. Fifteen ISSR
markers generated a total of 3773 bands, out of which 3770 were monomorphic among all the clones. The
Jaccard's similarity coefficient revealed that out of 45 clones derived from different explants, 44 were grouped
into a single large cluster alongwith the mother plant with a similarity coefficient value of 1.00, whereas one clone
(C38) remained ungrouped. The clones derived from capitulum and shoot tip explant s did not show any genetic
variation, whereas, one of the leaf-derived clones exhibited some degree of variation.
Genetic diversity of 29 commercial and 13 wild accessions of Barberton daisy (
Gerbera jamesonii
) was evaluated
by RAPD markers and morpho-agronomic characters. A total of 74 polymorphic bands were obtained using a set
of 12 primer pairs. The genetic similarity coefficient was evaluated by Jaccard index and the genetic structure was
evaluated by hierarchic classification analyses and UPGMA modeling. Shannon (
H
′) index analysis using the
molecular markers showed higher values of genetic diversity for the commercial cluster in comparison to the
values obtained for the individuals from the non-commercial cluster. Results indicated the presence of higher
genetic variation among commercial accessions in comparison to the cluster representing non-commercial
accessions, suggesting that genetic breeding programs may focus on commercial accessions to recombine
interesting genotypes with commercially important and marketing-desired characteristics (Mata et al., 2009).
Flower color is one of the main important morphological aspects in genetic breeding programs. The use of
molecular markers may serve to direct crossings, new hybrids and mutants, besides confirm and identify new
genotypes for commercial purposes. The genetic divergence among six cultivars of
Gerbera jamesonii
was carried
out with 21 primers, which amplified 37 DNA polymorphic fragments. The results showed that the RAPD is a fast,
relatively inexpensive and useful technique for genetic divergence characterization between different cultivars of
Gerbera jamesonii
[319]
.
Sheela et al. (2006) analysed seventeen
Heliconia
species and varieties using RAPD markers and found a strong
parallelism between genetic and morphologic/taxonomic variability of
Heliconia
genotypes.
The daylily (
Hemerocallis
spp.) is one of the most economically important ornamental plant species in commerce
(Tomkins et al., 2001). In order to determine the effects of intensive breeding on cultivar development, and to
study relationships among different species, genetic variation in the daylily was estimated using AFLP markers.
Nineteen primary genotypes (species and early cultivars) and 100 modern cultivars from different time periods
were evaluated using 152 unambiguous bands derived from three AFLP primer combinations. When comparing
cultivar groups from different time periods (1940-1998), genetic similarity was initially increased, compared to
the primary diploid genotypes, remained constant from 1940 to 1980, and then steadily increased as breeding
efforts intensified and hybridizers began focusing on a limited tetraploid germplasm pool derived by colchicine
conversion. Among modern (1991-1998) daylily cultivars, genetic similarity has increased by approximately 10%
compared to the primary genotypes. These data were also used to evaluate recent taxonomic classifications among
