Breeding and Seed Production of Ornamental Crops (2+1)

Breeding of gladiolus

Introduction:

• Gladiolus is one of the most important bulbous flowering crops grown commercially for cut flower trade in India.
• Breeding work in gladiolus has been carried out at IARI, New Delhi; IIHR, Bangalore; NBRI, Lucknow, IHBT, Palampur and Horticulture Experiment and Training Centre, Chaubattia.
• Gladiolus is hermaphrodite in nature, so new cultivars are evolved through hybridization and mutation. It belongs to family Iridaceae.
• The basic chromosome number in the genus is 30 but the number present in the typical modern gladiolus is 60.
• Many features and characteristics of gladiolus show a gradual variation from one extreme to another. It is primarily due to its polyploidy nature.
• Breeding work in gladiolus has been initiated with following objectives.

Objectives:

• To develop new cultivars with improved plant growth.
• To get better spike quantity.
• To develop new colour.
• To get desired size and form florets.
• Symmetrical arrangement of the florets on the spike.
• Bud counts and compactness.
• High rate of corm and cormel multiplication.
• Stem types such as slenderness and flexibility to high wind.
• Resistance to pests and diseases.

Important groups and species of gladiolus:
On the basis of their geographical origin, botanists listed the gladiolus species into four groups viz.

1. Eurasian group
2. East African group
3. Natalensis group
4. South African Cape species

Table. Species distribution and characteristics of some gladiolus groups

Group	Species	Distribution	Remarks
Eurasian	G.atroviolaceous	Syria, Jordan valley, Lebanon and Near East	Flat leaves and irrespective of weather conditions, shoots emerge during February and flower during May to July
	G. byzantinus	West and South East Europe	Narrow leaves and the first leaf is sword like and stem is branched. Cormels have net like husk and it protects even at -15°C
	G. communis	Near East, USSR, Western Asia and parts of eastern Europe	Unbranched stem with few leaves and 4-8 florets
	G. cardinalis	South Africa	Arching stem with 5-7 buds with scarlet red flowers reversing upward on the stem and grows in upland near waterfalls
	G. floribundus sp. miniatus	South Africa	Upright flowers which are large and plain rose pink and plant height is about 60 cm
	G. floribundus subsp. rudis	South Africa	Light pink flowers facing upright with three yellow lilac blotches formed on 40 cm tall plant
East Africa	G. aequinoctalis	South, South West and West Africa	Strong fragrance, thin drooping stem with 5-7 star shaped florets with tubular neck. Grows well in wetlands and is a triploid
Natalensis	G. psittacinus var. hookeri	All over the world	Pentaploid (5n=75), grows 1.75 m tall, late flowering and takes 190 days from planting to flowering, self sterile and highly prolific
	G. psittacinus var. cooperi	Africa	Less prolific with muddy greenish yellow flowers
	G. psittacinus var. dracocephalus	Africa	Narrow pointed flower, maroon and green speckled
	G. primulinus	South Africa	Small sized flowers, clear yellow colour, heavily veined with orange lines
South African Cape Species	G. maculatus	South Africa	Strongly fragrant with freesia like flowers
	G. odoratus	South Africa	Slightly fragrant, 6-9 flowers fromed on 30-40 cm long, slender erect stem
	G. oppositiflorus	South Africa	Very tall plant, grows upto 15 cm with 20-30 buds of which 15-18 will fully open at a time in pairs and top petals is hooded
	G. orchidiflorus	South Africa	Florets resemble orchids with throat markings in 3 lower petals which appear in 15-25 cm long shoots and sweetly fragrant
	G. saundersii	South Africa	Fan shaped leaves arise from the centre of the flat corm, stem is erect with 5-7 buds
	G. sempervirens	South Africa	Evergreen leaves 10-12 in number and root is intermediate between corm and rhizome with a number of fleshy roots. Stem is very thin and the flowers held in erect in strong winds
	G. tristis	South Africa	Florets are 3-10, spaced widely on the stems which are fragrant during evening. All the six petals are of similar size facing upwards.