International Journal of Horticulture, 2017, Vol.7, No.22, 180-204
180
Review Article Open Access
Improvement of Ornamental Plants - A Review
L.C. De
ICAR-NRC for Orchids, Pakyong, Sikkim, India
Corresponding email
International Journal of Horticulture, 2017, Vol.7, No.22 doi
Received: 06 Aug., 2017
Accepted: 12 Aug., 2017
Published: 15 Sep., 2017
Copyright
©2017 De, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
De L.C., 2017, Improvement of ornamental plants -a review, International Journal of Horticulture, 7(22): 180-204 (doi
Abstract
Ornamental crops provide better income from a unit area with higher profitability. There is huge untapped flower
production potential in our country which could benefit a large segments of the weaker sections of the society. Both the domestic
market and the export potential of flowers and ornamentals are tremendous. Besides, earning foreign exchange and improving the
national income, the floriculture business being labour intensive generates gainful employment to rural youth. Ornamental plants are
appreciated by their ability to please the eye of consumers as garden or pot plants or when sold as cut material. The main emphasis
in ornamental plant breeding is to improve variety traits, novel colour, form, size, number of flowers, flower vase life, repeat
blooming, disease resistance, nutrient uptake capacity and growth habit. Various types of new varieties of ornamental crops have
been produced for many years by cross hybridization and mutation breeding techniques, separately or in combination. Many
ornamental plants have been originated from inter-specific and inter-generic crosses, which leads to high degree of heterozygosity in
the resulting hybrids, often polyploidy and aneuploidy also occur. In the present review, origin, modes of reproduction, introduction,
selection, hybridization, mutation and polyploidy breeding of various ornamental plants are discussed in details.
Keywords
Varieties; Flowers; Hybrids; Hybridization; Polyploidy; Selection
1 Introduction
Ornamental plants include woody and herbaceous as well as annuals, bi-annuals and perennials. Ornamentals are
grown as both seed propagated and vegetative propagated cultivars. A general characteristic of ornamentals is
assessed by their quantitative capacity for production of seeds or other plant organs. Utilization of polyploidy
both auto-polyploidy from spontaneous or induced chromosome doubling and allo-polyploidy from spontaneous
or artificial interspecific hybridization is widely used among ornamentals to rapidly combine traits and to create
giant type of flowers and leaves. In seed propagated ornamentals, with a considerable seed marked, cultivars will
normally be bred as hybrids based on inbred parental lines.
Ornamental plants are appreciated by their ability to please the eye of consumers as garden or pot plants or when
sold as cut material. For these reasons, cultivars or ornamentals must fulfill aesthetic criteria in demand. The
main emphasis in ornamental plant breeding is to improve variety traits, novel colour, form, size, number of
flowers, flower vase life, repeat blooming, disease resistance, nutrient uptake capacity and growth habit. Recently,
many spectacular shades and forms like dwarf hollyhocks, dwarf delphiniums, uniform perfumed cyclamen, red
and white marigolds, blue roses and carnation, yellow antirrhinum, fragrant gladioli, coloured tuberose etc. have
great demand in ornamental trade (Raghava, 1999).
2 Origin of Ornamental Plants
The origin of a crop is determined by the collection of existing forms of cultivated and wild species in a particular
area.
Indian origin
: The important flowers which are natives of India cultivated in different parts of the world are
orchids, rhododendrons, musk rose (
Rosa moschata
), begonia, balsam (
Immpatiens balsamina
), globe
amaranth(
Gomphrena globosa
), gloriosa lily (
Gloriosa superba
), foxtail lily (
Eremerus himalicus
), primula
(
Primula denticulata P.rosea
), blue poppy (Meconopsis), lotus (
Nelumbo nucifera
), water lily (
Nymphaea
spp.),
