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8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 1/21
LIWANAG, IRISH D.AGRONOMY 152-T 1L
A GENETICRESOURCES:STATUS,PROBLEMS,
ANDPROSPECTS
8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 2/21
•Cowpea•Vigna unguiculata
L. Walp
•Paayap•Considered to haveoriginated in Africa
•Widely grown inafrica, latin America,Southeast Asia,
Southern UnitedStates
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PEA
8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 3/21
•Order: Fabales
•Family: Fabaceae
•Genus :Vigna
•Species: unguiculata
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PEA
8/3/2019 Cowpea - Final
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Four cultivated subspecies arerecognised:
1. Vigna unguiculata subsp. cylindrica Catjang2. Vigna unguiculata subsp. dekindtiana AfricanCowpea
3. Vigna unguiculata subsp. sesquipedalis Yardlongbean
4. Vigna unguiculata
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PEA
8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 5/21
BIOLOGY
Warm-season annual legumeLeaf is somewhat shiny and flower
color is either purple, white or yellowSeed color is diverse, ranging fromwhite, black, brown, purple to
various types of mottled seedPod length is from 20 to 30cmPod attaches sideward or downwardto the peduncle.Length of seed is 6 to 10mm
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PEA
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8/3/2019 Cowpea - Final
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Uses
Weed control•grows quickly and will shade
and smotherWeeds•may outcompete them for
soil moisture andnutrients
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PEA
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8/3/2019 Cowpea - Final
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Attract beneficialinsects•extrafloral nectaries onpetioles and leaflets;
− nourishes beneficial
insects such ashoneybees,
lady beetles,
predatory wasps, ants,-
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PEA
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8/3/2019 Cowpea - Final
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Feed and Food
when grown to maturity can be
used as a feed (grazedor harvested for fodder), or itspods can be harvestedand eaten as a vegetable
seed is valued as a nutritionalsupplement to cereals and anextender of animal proteins.
UsesOW
PEA
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8/3/2019 Cowpea - Final
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Protein 24.8%
Fat 1.9%
Fiber 6.3%Carbohydrate 63.6%
Thiamine 0.00074%
Riboflavin 0.00042%Niacin 0.00281%
Table 1. Nutrient content of mature cowpea
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PEA
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8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 10/21
Germplasm diversity
• IITA holds the largestcowpea germplasm
collection− 15,115 accessionswere collected all
over the world− 10, 814 werecollected from Africa
alone
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PEA
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8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 11/21
Germplasm
diversity
•Improved varieties in 63
countries−some of which have beengiven popular local namessuch as ‘Vijaya’ (victory) and
‘Varuni’ (breeze) in Sri Lanka;‘Akash’ (sky) and Prakash(light) in Nepal; ‘Big Buff’ in
Australia; ‘Fahari’ (hope) and
‘Tumaini’ (pride) in Tanzania;
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PEA
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8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 12/21
Germplasm diversity
Various tools arecurrently used to
analyze Vignadiversity:
• Isozymes forwild Vigna• SSR for primary
gene pool
• SNP for
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PEA
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8/3/2019 Cowpea - Final
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Extent of Genetic
Erosion
•diseases,insect pests,nematodes,
and parasitic
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PEA
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8/3/2019 Cowpea - Final
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Extent of Genetic
Erosion Every stage inthe life cycle ofcowpea has at
least one majorinsect pest.
•Aphids (Aphiscraccivora)attack cowpea
especially in the
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PEA
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8/3/2019 Cowpea - Final
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Extent of Genetic
Erosion• flower thrips(Megalurothrips
sjostedti) at flowering,pod borer (Marucavitrata) at flowering and
pod formation,
•a complex of pod-sucking bugs atpodding, and the weevil
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PEA
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8/3/2019 Cowpea - Final
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Extent of Genetic
Erosion
Cowpea issusceptible toseveral fungal,
bacterial, and viral
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PEA
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8/3/2019 Cowpea - Final
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•Cercospora leaf spot,• ashy stem blight,•bacterial blight,•blackeye cowpea mosaic
potyvirus (BICMV),•cowpea aphid-bornemosaic potyvirus (CABMV),•and cowpea mosaic
comovirus (CPMV).• Cowpea plants are alsoattacked by the parasiticflowering plants Striga
gesnerioides and Alectra
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PEA
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8/3/2019 Cowpea - Final
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GERMPLASM CONSERVATION
IITA’s Genetic Resources Center (GRC) 28,000 accessions
Over 50% of the collection is made of cowpea collected from 89countries, mainly in Africa, and other Vigna spp. It is also the mostshared, with 54 of all the germplasm materials being distributed.
IITA maintains a collection of about 15,000 accessions of cultivated
cowpea and 1,500 accessions of wild cowpea relatives in its genebank.
cowpea is maintained in two storage conditions, medium (5°C) andlong-term (-20°C) at an optimal water content of 7−8% fresh weight
basis. The viability of most accessions stored at –20°C for 25 yearsremains as hi h as 90%.
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PEA
8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 19/21
US$358,143 and$28,217 was spent
annually on theconservation andmanagement of cowpea
and wild Vigna.
Each accession costabout $72 for cowpeaand only about half ofthat for wild Vigna
Seed health testing
PEA PROBLEMS IN
GERMPLASMCONSERVATION
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8/3/2019 Cowpea - Final
http://slidepdf.com/reader/full/cowpea-final 20/21
estimated the annualworld cowpea crop at
12.5 million ha,
the total grain
production at 3 million t
64% of the estimated 3million t of cowpea seed
roduced annuall
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PEA ECONOMICALAND POLITICALASPECTS OF
CROPGERMPLASM
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8/3/2019 Cowpea - Final
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One way to reduce these costsis by increasing the number ofaccessions, thus lowering theunit cost. Also, upgrading andexpanding the current
infrastructure to improve theefficiency of the genebank wererecommended.
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PEA RECOMMENDATION