Four Seasons of Learning and Engaging Smallholder Farmers - icrisat

Figure 5-8: Reactions of some cultivated and wild cowpea seedlings to aphid infestation
Seedlings of the cultivated cowpea lines have collapsed following aphid damage while those of some
of the wild cowpea relatives did not show evidence of aphid damage.
Validation of molecular markers
Cowpea SNP Marker Validation: As part of the collaboration between TL I and TL II some molecular
markers found to be associated with desirable traits in cowpea at UC Riverside were validated at the IITA
facility, at BECA in Nairobi. Allele-specific primers were designed to capture SNPs linked to important
traits like SUR, Striga, Macrophomina/*CPMVnewb, Macrophomina, Gy-1, Gs-4, Gs-2,Flow-5, Flow-
1/2, Drought, DLS-5/6, DLS-4,DLS-3, DLS-1/2, CoBB-3, CoBB-2/DLS-4, CoBB-2, CoBB-1/CPMVnewb,
CoBB-1, Dehydrin, CPSMV and CPMVnewb. The SNPs were mined from the HarvEST:Cowpea v1.18
software which is a principally EST database. In order to design AS-PCR primer of extra 3’ mismatch,
WebSNAPER (http://ausubellab.mgh.harvard.edu/) was used. Primers without extra 3’ mismatch were
designed by use of DNASTAR Lagergene Software (www.dnastar.com/). PCR was performed using
AccuPower ® PCR PreMix (www.bioneer.com). Total of 10 SNPs appeared as reliable plus/minus scoring
on agarose gel of the PCR products (Table 9). These are the SNPs, converted to the agarose gel assay
format and utilized to test 32 samples from a cowpea breeding population at IITA.
100
Engaging Smallholder Farmers | Tropical Legumes II Project