International Journal of Horticulture, 2015, Vol.5, No.21, 1-45
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biosynthesis pathway (Datta, 1992, 1997; 1998a, 1998b, 2001).
Role of phenolic compounds in solving different taxonomic problems in different crops have been reported earlier
(Bose, 1975; Bose and Frost, 1967; Frost and Holm, 1971; Fahselt and Ownbey, 1968). It has been reported that
species and variety specific spots for phenolic compounds occure in a large number of plants. Both naturally
occurring and experimentally-produced hybrids can, therefore, be detected early through thin layer
chromatographic analyais of phenolic compounds in different plant parts. Alston and Turner (1963) have
recognized a large number of species specific spots for phenolic compounds in
Baptisia
and numerous
interspecific hybrids. Hunter (1967) has been able to demonstrate that
Vernonia gandalupensis
is really a natural
hybrid between V. lindhermeri and V. interior, because all the parental compounds could be recognized in the
interspecific hybrids. Species and variety specific phenolic compounds could be recognized in a number of plant
species and F
1
hybrids have been identified by detecting summation of parental compounds as has been done in
Viola
(Stebbins et al., 1963),
Phlox
(Levin, 1966, 1967), Saxifraga (Jaworska and Nybom, 1967), Vinca (Stebbins
et al., 1963),
Trichosanthes
(Datta, 1987) (etc. Significant qualitative and quantitative differences in
chromatographic pattern of phenolic compounds in leaves and petals were observed in new mutant varieties of
bougainvillea, chrysanthemum and rose (Datta and Basu, 1976; Datta, 2001, 1997). These changes might be due
to alternation in biogenesis of certain phenolic compounds or degradation of some of the existing phenolic
compounds of the original cultivars.
Scanning electron microscope is most commonly used for studying the leaf/seed epidermal micromorphology,
morphology of the pollen taxa etc. for solving various taxonomic problems (Robinson, 1971; Sharp et al., 1978;
Brisson and Peterson, 1977; Cole and Behnke, 1975; Trivedi et al., 1978; Haridassan and Mukherjee, 1987;
Patricia and Clark, 1990). Petal micromorphology studies of original and mutant cultivars of chrysanthemum and
rose revealed considerable variation, particularly in cell boundaries, cell surface, striations and papillae not only
between the original cultivars but also between the original cultivars and their respective induced mutants. Studies
indicated that flower colour change due to mutation was also associated with some changed micromorphology of
petal surface. It clearly indicated that petal micromorphological characters can be utilized not only for identifying
mutants but also a correlation study will help the proper identification of different present day cultivars of
chrysanthemum and rose and their origin (Datta and Shome, 1994; Datta, 1997; 1992).
Pollen morphological features are well accepted in present days as unique stable characters which may be used as
important diagnostic characters for identification even at microtaxa level.The pollen morphological characters are
categorized as appertural, exine ornamentation, exine strata, shape and size in order to their importance and
stability. Pollen morphological features especially aperture and exine ornamentation patterns have been used as
important diagnostic characters to study the interrelationship and taxonomic and cytological status of the cultivars
and even of individuals of the plant population (Lewis, 1965; Nair, 1970). A number of studies have been carried
out in the field of cytopalynology to study the nature of hybridity and the effect of polyploidy on pollen
morphology (Henderson, 1972; Quiros, 1975; Srivastava, 1976; Chaturvedi et al., 1990). These characters are
genetically stable and any change in any of the regulating characters indicates some changes in those features. The
pollen morphological characters of large number of original and their gamma ray induced mutant varieties of
chrysanthemum and
Lantana depressa
were analysed and found variations in the nature of endocolpium and some
ultra surface patterns (Datta and Datta, 1998)
.
Electrophoresis of crude proteins and enzyme extracts has been successfully used to establish phylogenetic
relationships, identification of varieties, intra and inter subspecific variation of different taxa in various groups of
crop plants. Protein and isozyme polymorphism has been successfully used for demonstrating genetic variation,
identifying interspecific hybrids, and finger printing cultivars (Cherry et al., 1971; Nainawatee and Das, 1972;
Challice, 1981; Coehen and deWET, 1981; Cardy and Kannebberg, 1982; Chaparro, 1987; Ellstrend, 1984;
Oshima, 1993; Chang et al., 1995; Obara-Okeyo and Kako, 1997; Huang et al., 2000; Kuhns and Fretz, 1978).
Kuhns and Fretz (Kuhns and Fretz, 1978) have shown how by combining the results for several isozyme systems,
a clear separation could be achieved between the rose cultivar ‘peace’ and three of its sports ‘Chicago Peace’,
