Biology Reference
In-Depth Information
Chapter 10
Enabling Tools for Modern Breeding of
Cowpea forBioticStress Resistance
Bao-LamHuynh,JeffreyD.Ehlers,TimothyJ.Close,NdiagaCisse,IssaDrabo,Ousmane
Boukar,MitchellR.Lucas,SteveWanamaker,MartiPottorff,and PhilipA.Roberts
Abstract
This chapter summarizes recent advances in genomic resources, technologies, breeding platforms,
and molecular markers that are being used to expedite delivery of cowpea cultivars with resistance
to important biotic stresses. The genomic resources available in cowpea include high-throughput
single nucleotide polymorphism (SNP) genotyping platforms, a high-density consensus genetic map
with more than 1,100 markers, a whole genome sequence assembly, bacterial artificial chromosomes
(BACs), and a physical map anchored to the genetic map. Markers linked to important biotic resistance
traits, including resistance to foliar and flower thrips, Fusarium wilt, root-knot nematode, bacterial
blight, ashy stem blight (
Macrophomina
),
Striga
, and viruses are described, together with tools
developed to integrate SNP genotypes, genetic maps, and trait information to guide breeding. A
genetic transformation system has been developed for cowpea and breeding lines developed with
resistance to cowpea weevil and Maruca pod borer. Some examples of initial work in evaluating and
optimizing marker-assisted backcross and marker-assisted pedigree breeding are described. Major
challenges that must be overcome to allow for the adoption of modern marker-assisted breeding
(MAB) in cowpea include human and precision phenotyping capacity issues. Further, as essentially
all cowpea breeding is being conducted by the public sector with modest resources, efficient strategies
are needed to minimize running costs.
being cultivated, of which about three-fourths
of the area and two-thirds of the production
occur in the semi-arid Sudan savanna and Sahe-
lian zones of the African continent running from
west to east, south of the Saharan desert, and in
more dispersed but extensive pockets of similar
agro-ecologies in eastern and southern Africa.
Introduction
Cowpea (
Vigna unguiculata
L. Walp.) is perhaps
the most widely adapted, versatile, and nutritious
grain and fodder legume for warm and dry agro-
ecologies of the tropics and subtropics. World-
wide there are more than 14 million ha of cowpea
Search WWH ::
Custom Search