Origin, Progenitor, classification, Floral biology, breeding objectives and breeding methods in cowpea, KAU varieties, vegetable cowpea

1. BREEDING OF COWPEA
ARUN CHACKO
PhD Scholar
Plant Breeding & Genetics

3. • Cowpea is one of the most important food and forage legumes
in the semi-arid tropics that include parts of Asia, Africa,
Southern Europe, Southern United States, and Central and
South America.
• It is truly a multifunctional crop, providing food for man and
livestock and serving as a valuable and dependable revenue-
generating commodity for farmers and grain traders.
• A drought tolerant and warm weather crop, cowpea is well
adapted to the drier regions of the tropics, where other food
legumes do not perform well.
• It also has the unique ability to fix atmospheric nitrogen
through its nodules, and it grows well even in poor soils with
more than 85% sand and with less than 0.2% organic matter
and low levels of phosphorus.

4. • Cowpea grains complement the grains of cereals
as foods for people by enhancing the quantities
and qualities of proteins and vitamins.
• cowpea grains have substantial levels of folic
acid, which is a critical vitamin for all people and
especially pregnant women.
• Storage proteins in cowpea seeds are rich in the
amino acids lysine and tryptophan.
• Cowpea leaves and stems (stover) are also an
important source of high-quality hay for livestock
feed.

5. Diploid with 2n = 2x = 22
Progenitor:
• the wild cowpea, Vigna unguiculata ssp.
unguiculata var. spontanea (formerly
var.dekindtiana)
• found in all low lying areas of Sub Saharan
Africa(SSA)
• Centre of origin for wild cowpea: S. Africa
• Synonymous-Lobia, Barbati, Black eyed pea

6. Taxonomical classification

7. • The genus Vigna comprises about 85 species, which
divided into seven subgenera, namely Ceratotropis,
Haydonia, Lasiocarpa, Macrorhycha, Plectotropis,
Sigmoidotropis and Vigna.
The Asiatic Vigna includes
• green gram (Vigna radiata),
• black gram (Vigna mungo)
• rice bean (Vigna umbellata) of the subgenus
Ceratotropis,
• Cowpea along with its cross-compatible wild relatives
are in a subgenus of Vigna.

8. The five cultivar groups of cultivated cowpea
Cultivar Group Selected Feature
Ungiculata Includes most African grain and
forage types. More than 16
ovules/pod
Melanophthalmus Black eye pea types, < 17 ovules/pod,
mostly grown in America
Biflora (Catiang) Smooth seed in short erect pods, <
17 ovules/pod, common in India
Sesquipedalis Asparagus/Yard long bean, very long
pods
Textilis Rare form with very long peduncles,
used for fibre in Africa

9. • Of the domesticated Vigna species, cowpea and mungbean
are the most important in terms of production.
• Rice bean (V. umbellata) is locally important in parts of
northern India and Southeast Asia.
• Moth bean (V. aconitifolia) is an important crop in drier
parts of South Asia.
Moth bean (V. aconitifolia) Rice bean (V. umbellata)

10. The genus Vigna
• The Vigna species grow in warm temperate
and tropical regions globally.
• Vigna is most closely related to Phaseolus,
hence Asia Vigna (subgenus Ceratotropis) was
treated as Phaseolus until 1970.
(Verdcourt, 1970).

11. African Vigna Cultigens (subgenus Vigna)
• Vigna cultigens were domesticated from African
Vigna (subgenus Vigna), Eurasian Vigna (subgenus
Plectotropis) and Asian Vigna (subgenus
Ceratotropis).
• Two species, cowpea (Vigna unguiculata) and
bambara groundnut (Vigna subterranea) were
domesticated from African Vigna probably in West
Africa.

12. • Bambara groundnut (Vigna subterranea) domesticated from African Vigna
(subgenus Vigna) probably in West Africa.

13. Eurasian Vigna Cultigen (subgenus Plectotropis)
• Fully domesticated
form of Vigna
vexillata (named as
Tuber Cowpea) was
recently found
cultivated in Bali and
Timor, Indonesia.

14. Asian Vigna Cultigens (subgenus Ceratotropis)
Six species have been fully domesticated from 21
species of Asian Vigna (subgenus Ceratotropis).
• Mungbean (Vigna radiata), black gram (Vigna
mungo) and moth bean (Vigna aconitifolia) are
considered to have been domesticated in India.
• Rice bean (Vigna umbellata) and creole bean
(Vigna reflexo-pilosa var. glabra) were
domesticated in Southeast Asia and azuki bean
(Vigna angularis) in East Asia, most probably in
Japan

15. • Mungbean (Vigna radiata) domesticated from Asian Vigna
(subgenus Ceratotropis) in India.

16. • Moth bean (Vigna aconitifolia) domesticated from Asian Vigna
(subgenus Ceratotropis) in India.
• Upper row: cultigen, Lower row: putative wild form.

17. • Rice bean (Vigna umbellata) domesticated from Asian Vigna
(subgenus Ceratotropis) in Southeast Asia.

18. • Vigna belong to the hot weather herbaceous
legumes, those legumes that do not grow or
survive in the winter season in temperate
regions.
• Vigna is closely related phylogenetically to the
agriculturally important genera Cajanus,
Glycine, and Phaseolus.

19. The main characteristics that distinguish Vigna from
the very closely related genus Phaseolus
Phaseolus Vigna
Stipule Attached to stem
by its basal part
Attached in
several ways
Tuberacles Absent Present
Keel Narrowly curved
around the style
Variously shaped
Style Curved through
360o
Curled or may not
be curled
Stigma At the end of style Laterally to style
as tip of style
elongates into
style beak

21. Classification
According to Faris 1965 three subspecies are recognised.
1. Vigna unguiculata subsp. unguiculata (Syn V.u. subsp.
catjang) - grain cowpea : Primitive of all cowpea types. Pods
8 to 13cm long. Neither flabby nor inflated. Pods remain erect
at maturity.
2. V.unguiculata subsp. sinensis - Grain type cowpea. Pod
length 20 to 30 cm. Pods are not inflated. Pods fibrous when
green. The stature of pods are pendent when matured. Seed
size medium 6-9 mm. Seeds are closely packed in the pod.
3. V.unguiculata subsp. sesquipedalis - Yard long bean –
vegetable cowpea: Pod size may be 30 to 100 cm, pendent.
No fibre content is geeen pods. Seeds are sparsely arranged,
kidney shaped and usually double coloured. Pods inflated
when green, shriveled on drying.

22. Inflorescence
• It is composed of axillary racemes, with 2-12 flowers in each
peduncle.
• Peduncle is 4-30 cm long, glabrescent at top, purplish at base.
Rachis is glabrescent, tuberculate.
Flower
•It is bisexual, white, purple or pale violet.
•Fertile flowers are paired, laterally inserted into a tubercle.
•Bracts are one per flower and deciduous, about 3-4 mm long,
fleshy at base, with ciliolate edge.
•The flower is complete with five sepals and five petals. The keel
petal is straight, the standard petal is whitish to violet in colour.
•The stamens are 10 in nos. in which 9 are fused and 1 is free.
•The ovary is multilocular, the style is right angled and
pubescent, stigma is oblique .

24. Calyx
• The calyx is composed of five sepals, which are
gamosepalous. The two are large and three are small
which makes 2+3 arrangement of sepals.
Corolla
• The corolla is composed of five petals same as in case of
chick pea. It consists of one large standard, two wings and
two keels which are straight and purple in color.
Androecium
The androecium is diadelphous (9+1). The nine stamens are fused
and one is free.
Gynoecium
The style is right angled and is hairy on inner side, with a
terminal stigma; the ovary is monocarpellary with many ovules
and is unilocular.

27. Anthesis and Mode of Pollination
• Self-pollination
• In about 50% of the flowers the buds do not open (i.e.
they are cleistogamous).
• The flower opens in the early mornings, i.e. from 6 to
8 a.m., and may remain open till 11 a.m..
• The dehiscence, however, takes place about 3 to9 hrs
before the flower opens.

28. Emasculation and Pollination
• Fertilization occurs in the bud stage.
• The age of the bud appropriate for emasculation is
indicated by the appearance of the corolla just above
the calyx.
• Immature anthers can easily be removed at this stage
with a pair of forceps or with a needle.
• All the buds except those which are to be emasculated
are removed.
• One day after emasculation the anthers collected from
the newly opened flowers of the male parent are gently
rubbed on the stigma of the emasculated flower.
• The petals of the emasculated flowers are again brought
to the normal position.

29. • Another method of emasculation in cowpea
requires removal of the entire corolla.
• Then push a soda straw of optimum length
over the pistil and pinch the upper end of soda
straw with adhesive tape.
• Tagging is done as usual.

30. Pollination
• The mature anthers are collected in the next
morning and pollination is done by gently
rubbing ripe anthers against the stigma of
female flowers.
• After applying the pollen, the soda straw
should be replaced and left until fertilization is
completed.

31. Fruit
• The pods are 20 -30 cm long,
cylindrical and slightly curved,
with a thick beak slightly
constricted between the seeds the
seeds are variable in size and
color.
• Abortion Problem: There is high
rate of abortion in cow pea, which
can shed 70 to 80 % of its 100 to
500 flower buds prior to anthesis.
Only 6 to 16% of the total flower
buds produce mature fruits.

32. Breeding of Cowpea

33. Breeding objectives
Breeding for
• Medium Duration high Yielding Varieties for dry land
Conditions
• Short Duration varieties Suited for Irrigated and Mixed
Cropping Conditions
• Dual purpose (seed and vegetable type and seed and fodder)
• Vegetable Cowpea
• Disease Resistance
• Pest Resistance
• Abiotic resistance
• Forage Cowpea

34. Breeding methods
Cowpea is a self-pollinating plant and the
breeding methods that have been widely and
successfully used for its improvement are:
–Pure line selection,
–Mass selection,
–Pedigree method,
–Backcross breeding,
–Single seed descent method.

35. Introduction
• India is believed to be the center of cowpea diversity
because of two important “cultigroups” viz. Biflora
and Sesquipedalis which have evolved from
Unguiculata in India and Southeast Asia, respectively
under intensive human selection.
• Introduced varieties: Iron cowpea, Russian giant

36. Variability in Cowpea

37. Selection
Pusa Barsati:
• It is a selection from exotic materials from Philippines.
Vellayani Jyothika
• Selection from Sreekaryam local
Malika
• Single plant selection from Thiruvanathapuram
Sharika
• Single plant selection from Valiyavila local
CO 4
• Selection from Russian Giant

38. Pureline selection
• Involves a selection of promising individuals
from segregating populations after systematic
crossing or induced mutagenesis.
• Selected individuals are harvested individually
and continuously selfed and selected to
develop and release Pure line cultivars.
Vyjayanthi
• Pole type cowpea, pink long pods – selection
from Perumpadavam local.

39. Pedigree breeding
• Maintains detailed records of the relationship between
the selected plants and their progenies.
• In this method, each progeny in every generation can be
traced back to the F2 plant from which it had
descended.
• It is commonly applied in selection of desirable plants
from the segregating populations of self- pollinated
crops.
• Pedigree method following crossing between two
parental Lines has been used for improving some
specific traits lacking in an already established variety.

40. Bulk population breeding
• Bulk population method is also known as mass selection or
population breeding.
• A portion of the bulk seed is used to grow the next
generation and individual plant selection is often started in
the F6 or later generation.
• Bulk selection method is useful to increase the frequency of
desirable types through positive mass selection.
• It is suitable for studies on the advancement of genes and
genotypes in populations and it offers greater chances of
isolation of transgressive segregants than pedigree method.
Hridya
• mass selection of the local Kuttipayar.

41. Backcross breeding
• Backcross breeding was used to transfer disease and
pest resistance genes, and to introduce genetic
variability in crop plants.
• It is used to transfer few genes into an established
cultivar of self- or cross-fertilizing crop.
• Backcrossing leads to increased homozygosity allowing
selection of desirable genotype in homozygous and
desirable genetic backgrounds.
• The use of new resistance genes from the wild have
steadily increased since many breeders have exploited
wild relatives for incorporating resistance to diseases
for over a century through backcross breeding.

42. Single seed descent selection method
• In this method, only a single seed collected from each
of the F2 plant is kept and bulked to grow the F3
generation.
• This process continues up to the F5 and F6 generations
whereby a desired level of homozygosity is achieved.
• In the F6, large number of single plants are selected
and their progeny grown separately.
• In the F7 and F8 best performing Lines are selected
for preliminary and national yield trials.

43. Mutation Breeding
• India is a pioneer centre for mutation research
on grain legumes.
Improved cultivars:
• V-16 (Amba), V-38 (Swarna) and V-240
• Co5 Forage cowpea (Mutant of Co 1 )

44. Hybridization
Pusa Do Fasali:
• It has been developed from cross of Pusa Phalguni and a
long podded introduction from Philippines.
Arka Garima
• V. Unguiculta TUV 762 x V. Unguiculata ssp. Sesquipedalis
Krishnamony (PTB 2)
• P118 x Kolinji Payar
Interspecific Hybridization
• Vigna ungiculata x Vigna vexillata - (having tuberous roots
which is edible)
• Vigna ungiculata x Vigna umbellata

45. Breeding for disease resistance
• Aphid borne mosaic virus
– Resistant variety – Kairali, Githika, Manjari
• Cercospora leaf spot
• Fusarium wilt
– Resistant variety: Mithra, Vellayani Jyothika
(tolerant)
• Anthracnose
– Resistant variety Bagya Lakshmi
• Dry root rot

46. Breeding for pest resistance
• Leaf hopper
• Black pea aphids
• Pod borer
• American leaf serpentine miner
• Pod bug

47. KAU Varieties
• Semi-trailing
• Trailing
• Bushy
• Grain type
• Dual purpose

48. Semi trailing
Kanakamony (PTB 1) Semi-trailing dual purpose type,
green pods, bold seeded,
suitable for kitchen garden
Anaswara Light green medium long pods
Kairali Violet coloured medium long
pods
Varun Long purple poded and bold
seeded

49. Trailing
Sharika High yielding, long white pods
with purple tip, seeds black in
colour
Malika High yielding, long wlight green
pods without purple tip, seeds
brown with a white speck having
irregular shape at one end
Lola High yielding, long light green
pods with purple tip and brown
seeds
Vyjayanthi Long wine red extra long pods
with brown seeds
KMV-1 Light green pods with brown tips
Vellayani Jyothika Light green pods, tolerant to
fusarium wilt
Manjeri local, Vyalathur local, Kurutholapayar, Geethika

50. Bushy
Bhagyalakshmy Bushy growth habit with light
green medium sized pods.
Grain type
•Krishnamony(PTB-2),
•Pournami (in summer rice fallows)
•Shubra (summer rice fallows during summer in Southern districts of
Kerala)
•Hridya (summer rice fallows of Onattukara)
Dual purpose type
•Kankamony(PTB-1),
•Anaswara

51. Molecular breeding in cowpea

52. • Transgenic cowpea was developed by
inoculating in vitro-germinated seedlings of
cultivar Pusa Komal with Agrobacterium
tumefaciens strain and reported that this
transformation method is efficient and
reproducible and could be used to introduce
desirable genes into cowpea for biotic and
abiotic stress tolerance.

53. • Callosobruchus maculatus and C. chinensis are
the major storage pest, causing severe damage to
the cowpea seeds during storage and α-amylase
inhibitor-1 (αAI-1) gene of bean (Phaseolus
vulgaris) provides resistance to both the storage
pests.
• Agrobacterium mediated transformation method
was used to insert α- amylase inhibitor-1 (αAI-1)
gene from bean to Pusa Komal and generated
fertile transgenic cowpea.

54. Institutes involved in Cowpea Breeding
• International Institute of Tropical Agriculture
(IITA)
• Indian Institute of Pulses Research, Kanpur,
India
• National Pulses Research Centre, Vamban, TN