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Breeding of Leafy Vegetable crops
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WELCOMETO ALL
LEAFY VEGETABLES
Jitendra Chandra Chandola 33415
LEAFY VEGETABLES Amaranths : Amaranthus spp. Spinach Beet / Palak : Beta vulgaris
var. bengalensis Hort. Spinach : Spinacia oleracea L. Newzealand Spinach : Tetragonia
tetragonoid.es (Pall.) O. Kuntze Poi / Basella / Malabar Nightshade :
Basella alba L. Fenugreek / Methi : Trigonella foenum
- graceum L.
AMARANTHS There are leaf amaranths as well as
grain amaranths. The leaf amaranths are used for vegetable but the young plants with tender stems and leaves of grain amaranths are also eaten as leafy vegetable.
It is widely cultivated throughout India but more in southern regions (Tamil Nadu, Kerala. Karnataka, Andhra Pradesh), it is also grown in the hills in north India, especially the grain amaranths.
BIOSYSTEMATICS
Family : Amaranthaceae Genus : Amaranthus The genus Amaranthus is classified into
two sections, namely Amaranthus and Blitopsis.
All species for grains are under Amaranthus and leaf amaranths under Blitopsis.
Species : tricolor (Badi chaulai) Species : blitum (Choti chaulai) Among the leaf amaranths,
Amaranthus tricolor, is most popular in South Asia and India.
FLORAL BIOLOGY The flowers in Amaranths are borne
in cymes having both pistillate and staminate flowers.
In the species A. tricolor and A. blilum the cymes are mostly clustered in leaf Axils.
Origin The vegetable amaranth, A. tricolor
originated somewhere in South Asia or South east Asia Most probably, it is native to India.
CYTOLOGY
The genus Amaranthns has two basic chromosome numbers, x =16 and x = 17.
All the Amaranthus species are diploids with chromosome number 2n=32 or 2n=34. Only one species A dubius is a tetraploid, 2n=64.
Breeding System
The vegetable amaranths are predominantly self-pollinating due to the presence of a high percentage (10-25%) of male flowers per glomerule and more number of axillary glomerules.
The percentage of male flowers per glomerule being only 0.5-1.0 per cent with protogyny contribute to natural outcrossing in grain types.
Amaranth is mainly a wind pollinated crop.
BREEDING OBJECTIVES The yield of greens is the main character for improvement in the leaf
amaranths. Plant height, stem diameter and weight, leaf length, width and weight,
leaf/stem ratio, leaf colour (green/red) and days to 50 per cent bolting have direct and positive influence on the yield of greens.
The optimum leaf / stem ratio should be above one. Plants of medium height with broader leaves and medium-thick stem are
ideal for selection. Plants with lower levels of antinutrient compounds like nitrates and
oxalates are desirable for selection. Selection of stable lines for yield and bolting in different environments. The
emphasis should be on selecting late bolting lines. Breeding for resistance to important dieases, like damping-off (Pythium
spp.), while rust (Albugo hliti), leaf spot (Cercospora spp.) and insect pests, such as, Hymeria spp. and other caterpillars, stem borer (Lixus truncalulus) and root-knot nematode (A, feloiciog).
BREEDING METHODS Since leaf amaranths are predominantly self-pollinating mass
selection has been effective in their improvement. Pure line selection can also be adopted in breeding leaf types. Recurrent selection has been suggested for improvement of
heterogeneous landraces of the grain amaranth. Autotetraploidy was induced by colchicine in A. blitum and
other species. The induced tetraploids of A. blitum had larger number and bigger leaves with prolonged vegetable phase.
Autotetraploid Mutation breeding in grain amaranths by using chemical mutagens and gamma rays.
Several promising mutants were selected which had earliness, dwarf plant height, broad leaves, late bolting.
IMPROVED VARIETIES
Pusa Kiran : Suitable for kharif season. Leaves are glossy green.
Pusa Lal Chaulai : Suitable for kitchen garden. Pusa Kirti : Suitable for summer season. Pusa Choti Chaulai : Plants are small in structure. It
respond well to cutting. Pusa Badi Chaulai : Plants are tall ; stems are thick and
tender with large green leaves. Arka Varna : high antioxidants with low oxalates and
nitrates. Arka Samraksha : high antioxidants with low oxalates
and nitrates. Arka Arunima : Resistant to white rust.
SPINACH BEET
It is a very common leafy vegetable in India, particularly in northern plains of Uttar Pradesh, Bihar, West Bengal, Rajasthan, Punjab and Haryana.
It is also grown in Maharashtra, Gujarat and Madhya Pradesh but not so common in southern States.
The spinach beet probably had its origin in Indo-Chinese region. It was known in China in A.D. 647.
In India, perhaps it was first cultivated in Bengal. It was first recorded in the medicinal treatise, Carak Samhita, c. 600 B.C.
BIOSYSTEMATICS Palak, Bela vulgaris var. bengalensis Hort., belongs to the
genus Beta of the family Chenopodiaceae. It is closely related to beet root and sugar beet (B. vulgaris
ssp. cicla). The sea beet B. vulgaris ssp. maritima, is the ancestor of beet
root, palak and some other cultivars.
Cytology
The spinach beet / palak is a diploid with a chromosome number, 2x=2n=18, the basic chromosome number being x=9.
Colchicine-induced aneuploids, triploids and tetraploids have also been reported.
GENETICS The red or purple colour of stems and leaves is dominant
over green and governed by two genes with a segregation of 9 purple: 7 green in F2 generation along with intermediate colours.
The monogerm seed character is controlled by a single recessive gene and multigerm was partially dominant, perhaps with some modifier genes.
The gene-cytoplasmic male sterility, reported in palak, was observed to be governed by two recessive genes with a 15:1 ratio in F2 segregation.
In the cross between garden beet and palak. early bolting was found to be governed by dominant genes. The higher dry matter content was controlled by dominant genes.
BREEDING OBJECTIVES To select for vigorous plant growth, quick growing,
strong succulent stem, large leaves, preferably green coloured leaves and stems.
Higher vitamin A content. Resistance to important diseases and insect pests. Higher yield. Better and quick rejuvenation ability after cuttings. Good flavour and taste. Wider adaptability to varying climate.
BREEDING METHODS Palak is a cross-pollinating crop, mainly due to wind-pollination. Mass selection and hybridization followed by pedigree method of
selection or bulk method are effective in improvement of the palak. Since there is inbreeding depression much selfing should be avoided
and instead sib- mating will be more effective. Recurrent selection may be adopted for the improvement of a
heterogeneous population. Colchicine-induced polyploids have also been selected for developing
improved cultivars. Crosses between palak and beet root, sugar beet and Swiss chard were
attempted to develop improved cultivars having late bolting habit and better rejuvenation ability and wider adaptability to varying climate.
The improved varieties were developed by selection from local types, hybridization between palak and sugar beet, Swiss chard or beet root and colchicine-induced polyploid.
IMPROVED VARIETIES All Green : The plants produced uniform green tender
leaves (6-7 cuttings). Pusa Palak : Selection from (Swiss Chard x Local
Palak). Pusa Jyoti : 2 % colchicines for 24 hours on All Green
variety. Pusa Harit : Sugar beet x Local palak. It tolerates to
alkaline soils. Jobner Green : Spontaneous mutant from local
collection of Sel. No. 5. Banerjee’s Giant : Palak x Beet root.
SPINACH Spinach is a temperate crop for growing in cool
season, there are a few varieties developed in china which are tolerant to warmer conditions and can be grown in subtropical regions of northern plains in India.
Origin
The spinach originated in central Asia, most probably in Persia. It was first grown by the Arabs in Persia about 2000 years ago.
The primitive forms of Spinacia oleracea have been reported from northwestern India and Nepal.
BIOSYSTEMATICS Family : Chenopodiaceae Genus : Spinacia. It is a dioecious annual. Sex expression in spinach is tetramorphic which includes :
(1) extreme male plants having smaller plants and earlier flowering,
(2) vegetative male plants with larger plants,
(3) female plants having larger size and longer vegetative period and
(4) monoecious plants which may be true-breeding or segregating for staminate and pistillate flowers.
The extreme male plants do not have any commercial use. In an improved variety extreme male plants are almost eliminated. The species Spinacea oleracea has two diploid wild relatives, S. tetranda and S.
turkesianica. Perhaps S. tetranda is the ancestor of spinach, Spinacia oleracea.
CYTOLOGY
Spinacia oleracea is a diploid with the chromosome number, 2n=12.
The sex gene is located on the short arm of the long chromosome 1.
The chromosome pair having the sex gene is the longest of the genome.
The long arm of the chromosome carries the X sex factor and short arm has the Y sex factor.
GENETICS SEX EXPRESSION There are various views on the sex determination in spinach. Most of
the reports suggested that there are XY sex factors along with autosomal sex genes, like A/a (maleness) and G/g (femaleness), M/m (monoecious), and Xm (monoecious).
Breeding Objectives
Uniform plants, erect leaves, large leaf size, short petiole. Selecting vegetative male and female plants and discarding or
eliminating extreme male plants, Late bolting, high yield, resistance to important diseases and
insect pests, low content of nitrate and tolerance to high temperature.
In Europe and the USA, breeding for processing quality is also important.
BREEDING METHODS Spinach is cross-pollinating and wind pollinated. The breeding procedures are the same as adopted in cross-pollinating
crops, such as, mass selection, sib-mating, recurrent selection, hybridization, pedigree method of selection, and bulk method.
Polyploidy breeding has been reported in spinach. Heterosis upto 30-40 per cent has been observed in Fj hybrids and
utilized for the development of downy mildew and mosaic resistant hybrids and cultivars.
The commercial hybrid seed of spinach is produced by planting 6 or 8 female rows of two promising dioecious parental lines alternating with one or two rows of a good combiner male parent.
At the time of bolting staminate (male) plants are removed from female / seed parent rows.
Hybrid seeds are harvested from the plants of the seed (female) parent.
IMPROVED VARIETIES The spinach varieties are of three types on the bassis of leaves,
viz., smooth leaved, semi-savoy and savoy. There are two types of varieties, classified on the basis of
seeds, like smooth-seeded and prickly- seeded. Among the introductions the two important varieties are : Virginia Savoy : plants are vigorous, upright, with blistered,
crumpled, thick and dart green leaves, late bolting and smooth-seeded. Its average yield is about 12.5 tonnes per hectare.
Early Smooth Leaf : It has thin leaves, yellowish-green in colour, smooth with pointed apex and smooth-seeded.
NEWZEALAND SPINACH
It is not a common leafy vegetable in India. It is grown on a limited scale, mostly in kitchen
gardens in the plains of North India and in the hills of north (Himalayas) and Ooty.
New Zealand spinach is a warm season crop and moderately tolerant to frost.
It is a native to New Zealand.
Biosystematics
Scientific name : Tetragonia tetragonoides (Pall.) O. Kuntze.
Family : Tetragoniaceae
INDIAN SPINACH The Indian spinach, Malabar Spinach or Malabar
Nightshade, Basella alba L. is also known as Poi. It is a commonly grown leafy vegetable in tropical
Asia including South Asia and Southeast Asia, China, Africa and tropical areas of the New World.
In India, it is cultivated in South India (Kerala, Tamil Nadu, Karnataka), West Bengal.
BIOSYSTEMATICS The Indian spinach. Basella alba L.
belongs to the family Basellaceae. The genus Basella has about nine
other species besides B. alba. A cultivar or form with heart-shaped
leaves is known as B. cordifolia. The species B. lucida is from India
and B. nigra from China.
CYTOLOGY The species Basella alba has the chromosome number
2x=2n=48. The chromosome number in B rubra is 2x=2n=44. induced
polyploids with 4x=88 chromosomes were produced in Basella alba and B. rubra.
Botany
Poi is a short day, succulent, annual or biennial and perennial in the humid tropics.
The plants are climbing having alternate broad ovate leaves with pointed apex,
Flowers small, sessile, white (B. alba) or pink borne in clusters on elongated thick peduncles,
Fruit enclosed in fleshy perianth.
CULTIVARS There are two types of cultivars,
1) Reddish petioles, stems and leaves (B. rubra)
2) dark green leaves, petioles and stems (B. alba).
Both red and green-leaved varieties are popular in West Bengal, Assam and South India and the green-leaved cultivars in Uttar Pradesh and Punjab.
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