This is my M.Sc. 1st seminar at Vegetable Science department of Bidhan Chandra Krishi Viswavidyalaya under my honourable chairman Prof. T. K. Maity.

1. Course No.: VSC 649 Date:09.03.2021
Masters’ Seminar: I
KRISHNENDU SADHUKHAN
M.Sc.(Hort.), 3rd Semester
Chairman: PROF. T. K. MAITY
Seminar Leaders:
DR. CHANDAN KARAK
DR. SIBSANKAR DAS
Faculty of Horticulture
Dept. of Vegetable Science
Bidhan Chandra Krishi Viswavidyalaya, Mohanpur
CROP IMPROVEMENT IN ONION (Allium cepa L.)

2. INTRODUCTION
Common Name: Onion
Scientific Name: Allium cepa
Family: Alliaceae (Old Amaryllidaceae)
Origin: Asia

3. 27%
20, 20%
2%
2%
2%
2%
2%
1%
1%
1%
39.6, 40%
Leading onion producing countries
China
India
Pakistan
Turkey
Brazil
Russia
Myanmar
Indonesis
Bangladesh
Viet Nam
Others

4. AREA AND PRODUCTION
 Onion is one of the important vegetable crops grown in
this country in a large area of 3,95,500ha producing
40,80,000mt bulbs for local consumption and export
perpose.
 India ranks third in export after Netherlands and Spain.
 In India Maharashtra is the leading onion producing state
with 23.4% area and 27.50% production followed by
Karnataka (19.90% area, 10.80% production).
 The average yield per unit area in India is very low (10.6
tonnes/ha).

5. Botany
 Biennial herb
 Leaves are tubular
 Bulbs are formed by attachment of swollen leaf base to underground
part of stem
 Flowers are produced during second phase after bulb formation
 Flowering structure : umbel
Taxonomy
 Class: Monocotyledon
 Kingdom: Plantae
 Division: Angiosperms
 Order: Liliaceae
 Family: Alliaceae
 Genus: Allium
 Species: cepa

6. Important Allium species
 Allium cepa Common onion
 Allium sativum Garlic
 Allium cepa var. ascalonicum Shallot
 Allium cepa var. aggregatum Potato onion or
multiplier onion.
 Allium cepa var. viviparum Tree onion
 Allium fistulosum Welsh onion or Japanese
bunching onion.
 Allium ampeloprasum Great headed garlic.
 Allium tuberosum Chinese Chive. Leaves are
consumed as leafy vegetable.

7. Classification of Allium cepa
Common onion: Allium cepa L. (2n=2x=16).
 With large bulbs born singly and propagated
through seeds.
 It mainly used as salad or curries.
Shallot: Allium cepa var. ascalonicum (2n=2x=16).
 Produces bulbs in clusters on surface of soil.
 The perennial onion produces seeds and propagated
through bulbs.
Potato onion or multiplier onion: Allium cepa var.
agrregatum (2n=2x=16).
 Producing small bulbs brone in clusters and
generally propagated through small bulbs.
Tree onion: Allium cepa L. var viviparum(2n=2x=16).
 It is a viviparous plant that grows as a perennial
underground bulb.
 Bulb-lets are also used for propagation.

8. TYPES OF ONIONS BASED ON COLOUR
The Colour of Onions
I.Yellow Onions are full-flavoured and are a reliable
standby for cooking almost anything. Yellow onions
turn a rich, dark brown when cooked and give French
Onion Soup its tangy flavour.
II. Red Onions, with their wanderful colour, are a
good choice for lots of fresh uses or for grilling and
roasting.
III. White Onions are often used in prepared salads,
white sauces, and is the traditional onion for classic
Mexican cuisine.

9. Table1: Nutritive value of Onion
Sr. No Item Value
1 Energy 166KJ /40 kCal
2 Carbohydrates 9.34 g
3 Sugars 4.24 g
4 Dietary fibers 1.7 g
5 Fat 0.1 g
6 Protein 1.1 g
7 Water 89.11 g
8 Thiamine (B1) 0.046 mg
9 Riboflavin (B2) 0.027
10 Niacin (B3) 0.166 mg
11 Pantothenic acid
(B5)
19 microg
12 Vitamin B9 7.4 mg
13 Vitamin C 23 mg
Source: https://www.slideshare.net

10. FLORAL BIOLOGY
 Anthesis occurs in early morning (6-7 hrs).
 Anther dehiscence is between 7.00 and 17.00 hr and on
next day also with peak between 9.30 and 17.00 hr.
 Pollen fertility is highest on the days of anthesis.
 Sigma respectively is also high on the day of anthesis
(Jones, 1933)
 The duration of anthesis is approximately 4 weeks on
interval umbel.

11. POLLINATION
Onion is cross-pollinated in nature and bees, flies and
other insects do pollination.
It is essential to ensure that there is sufficient population
of pollinating insects to achieve the full potential of
onion seed.

12. BREEDING
 Onion is indigenous to India. Natural variability is
created constantly due to its outbreeding nature.
 Local type cultivers like Nasik Red, Poona Red,
Patna Red and Bellary Red are the result of selection
by growers.
 As a result, a number of varieties of common onion
and multiplier onion have been developed.
 Introduction, mass selection, selfing and massing,
inbreeding, hybridization and heterosis breeding have
been used for improvement of onion.

13. Breeding objectives
1. High yield
2. Superior bulb quality traits (size, shape, colour, pungency,
firmness and dormancy), high total soluble solids content
important for dehydration industry, skin retention and high dry
matter
3. Resistance to diseases (purple blotch, basal rot, Stemphyllium
blight, anthracnose, pink root and bacterial rot).
4. Resistance to insect pests, mainly thrips
5. Resistance to abiotic stresses (moisture stress, high temperature,
salinity and alkalinity)
6. Development of high yielding varieties capable of producing
good seed yield
7. Development of varieties suitable for export market
8. Development of disease resistant F1 hybrids with superior quality
bulbs.

14. Germplasm resources
 Following centers in india are maintaining the onion
germplasms/lines) :
1. Directorate of Onion and Garlic Research (DOGR),
Rajagurunagar, Pune.
2. National Bureau of Plant Genetics Resources (NBPGR),New
Delhi.
3. Indian Institute of Horticultural Research (IIHR), Bangalore.
4. Indian Agricultural Research Institute (IARI), New Delhi.
5. Punjab Agricultural University, Ludhiana
6. Central Institute of Temperate Horticulture, Srinagar
7. Tamil Nadu Agricultural University, Coimbatore
8. Indian Institute of Vegetable Research, Varanasi

15. Characteristics of an ideal bulb
 Bulb should be attractive, uniform in size, shape,
colour and time of maturity.
 It should consist flavour (pungency) as per
requirement, high dry matter and long storage life.
 Additional desirable features are intact and
attractive skins, thick leaf scales (rings), single centred
bulb, thin neck and resistant to early bolting, disease
and pests.

16. Bulb colour:
 White colour is preferable for
dehydration because pigmented
dehydrated products are most preferred.
Bulb shape:
 Globe shape is preferred as it leads to
reduces waste during tailing and
topping.
Bulb size:
 5.0 to 7.5 cm bulb diameter is preferable
Pungency:
 High pungency is preferable
Density:
 Firm bulbs with higher TSS, dry matter
are preferred.

17. Genetic control of bulb colour in onion
 Bulb colour is one of the important traits in onion (A.
cepa L). Three major colours of white, yellow, red and
gold exist in onion germplasm.
 The bulb colour is due to flavonoid compunds and 54
kinds of flavonoids have been reported in onion
(Slimestad et al. 2007)
 The inactivation of dihydroflavonol 4-reductase (DFR)
in the anthocyanin synthesis pathway was responsible
for colour differences between yellow and red onions,
and two recessive alleles of the anthocyanin synthesis
gene were responsible for pink bulb colour (Kim et al.
2005b).

18. Breeding Methods
 Introduction, mass selection, selfing and massing, inbreeding, hybridization
and heterosis breeding have been used for improvement of onion.
Plant Introduction: Early Grando is an introduction developed by this
method. In long day types--- Brown Spanish has also been developed.
Selection procedure
 Mass–selection: Common in cross pollinated crops. Most of the varieties in
India have been developed by mass-selection.
 Selfing and Massing: This method is very good for improvement in a
crop, where inbreeding depression is common. Improvement in a cultivar can
be affected by selfing followed by massing Jones and Mann(1963). The
procedure are follows:
 First year (Bulb crop): Select 100 best bulbs of desired type.
 Second year (seed crop): Grow selected bulbs, self one or more umbles
per plant to initiate a separate line each.

19.  Third year (bulb crop): Grow the progenies of each inbreed lines
separately. Discard the poor performing lines during the growing season, at
harvest or in storage. Select at least 25 best lines and keep 15-20 bulbs of
each for selfing and open pollination next year.
 Fourth year (seed crop): Self pollinate 1-2 umbes in each plant and
allow others to open pollinate. Mass open pollinated seed and increase for
large scale production for one or more production.
 Fifth year (bulb crop): Grow the selfed progenies separately. Select
again the best 25 lines and 15-20 bulbs of each lines as above in the third
year.
 Sixth year (seed crop): Composite and plant bulbs of all selections in
a field or in a case for free open pollination in between the unrelated lines.
The open pollinated seed can be massed and increased as foundation seed.
o Inbreeding: In any onion improvement programme a considerable
amount of inbreeding or selfing is necessary. Brown paper bags and three
rings muslin cloth bags are used for selfing (Thamburaj and Singh 2015).

20. Hybridization : Used when we want to introduce characters from other
varieties
a) Intervarietal : very common
b) Interspecific : very rare
Utilized in A. cepa × A. fistulosum

21. Heterosis breeding:
 The F1 hybrids are high yielding with uniformity in bulb size, the
most desired characters.
 One of the main components for exploration of heterosis in onion
is isolation of male-sterile lines. The male-sterile lines have been
isolated in Pusa Red at IARI, (Netra Pal et al. 1986).
 Male-sterile lines have been also isolated at IIHR, Bangalore.
For heterosis breeding involves three important stages, namely
Production of inbreed lines
Testing combining ability of inbreed lines
Production the seeds of F1 hybrids.

22.  The onion disease and insect pests, which cause heavy
losses are; Purple blotch (Alternaria porri), Stemphyllium
blight (Stemphyllium vesicarium), Fusarium Basal rot
(Fusarium oxysporum f. sp. cepae) etc. and insect pests viz;
Thrips (Thrips tabaco) and Maggots (Delia antiqua).
 Germplasms showing resistance to various diseases and
insect pests have been identified and summarised in Table
2.
Breeding for disease and insect resistance

23. Table2: Sources of resistance to disease and insect pest in onion
Disease/Insect Level of resistance Source of resistance
Purple blotch Resistance IIHR 56-1
Moderately resistance Pusa Red, Pusa Ratnar, Arka
Kaiyan
Stemphyllium blight Tolerance IC-32176, 42900, 47954
Stemphyllium
blight+purple blotch
Tolerance IC-32176, 49121 and 48503
Basal rot Resistance Poona Red, Patna Red, IIHR-
141
Maggot Resistance A. Fistulosum (resistance to
Pink rot, Smut and onion
maggot)

24. Varieties :
 In India about 42 varieties have been developed by
different Institutions, Agricultural universities and
different Organisations.
Common Onion
Multiplier Onion

25. Table3 : Onion varieties developed in India.
Common onion (Allium cepa L.) Red coloured varieties
Variety Source Characters
Pusa Red IARI •Red colourd bulbs, flattish round shape.
•Yield 25-30 tonnes/ha.
•Very good in storage and wider
adaptibility.
Sukhsagar Local/farmers
varietiey
• Suitable for temperate and subtropical
regions.
• Widely cultivated in West Bengal. Yield
20-25 tonnes/ha
Bhima Supar DOGR,
Rajgurunagar
•Bulbs attain maturity within 100-105
days kharif and 100- 120 days late kharif
•Average yield 20-22 t/ha kharif and 40-
45 t/ha late kharif
Bhima Red DOGR,
Rajgurunagar
•Suitable for rabi and kharif season
•Yield 19-21 t/ha
Arka Niketan IIHR •Light-red, good for storage
•Yield 33 tonnes/ha
Arka Kalyan IIHR •Drak-Red, suitable for kharif season
•Yield 33 tonnes/ha

26. Scope of Breeding (Future Prospects)
 Proper breeding methods with improved crop
management practises.
 Use of heritability methods with improved crop
management practises.
 Quality Improvement in onion.
 Development of varieties which are desirable for
mechanical threshing and cultivation.
New tools of plant breeding include
A) Mutation breeding
b) Polyploidy
c) Plant Biotechnology
d) In Vitro Techniques and
e) Genetic engineering

27. Thank You