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Genetic mapping and legume synteny of aphid resistance in African cowpea (Vigna unguiculata L. Walp.) grown in California.

Huynh BL, Ehlers JD, Ndeve A, Wanamaker S, Lucas MR, Close TJ, Roberts PA - Mol. Breed. (2015)

Bottom Line: One minor and one major quantitative trait locus (QTL) were consistently mapped on linkage groups 1 and 7, respectively, both with favorable alleles contributed from IT97K-556-6.SNP markers flanking each QTL were positioned in physical contigs carrying genes involved in plant defense based on synteny with related legumes.These markers could be used to introgress resistance alleles from IT97K-556-6 into susceptible local blackeye varieties by backcrossing.

View Article: PubMed Central - PubMed

Affiliation: Department of Nematology, University of California, Riverside, CA 92521 USA.

ABSTRACT

The cowpea aphid Aphis craccivora Koch (CPA) is a destructive insect pest of cowpea, a staple legume crop in Sub-Saharan Africa and other semiarid warm tropics and subtropics. In California, CPA causes damage on all local cultivars from early vegetative to pod development growth stages. Sources of CPA resistance are available in African cowpea germplasm. However, their utilization in breeding is limited by the lack of information on inheritance, genomic location and marker linkage associations of the resistance determinants. In the research reported here, a recombinant inbred line (RIL) population derived from a cross between a susceptible California blackeye cultivar (CB27) and a resistant African breeding line (IT97K-556-6) was genotyped with 1,536 SNP markers. The RILs and parents were phenotyped for CPA resistance using field-based screenings during two main crop seasons in a 'hotspot' location for this pest within the primary growing region of the Central Valley of California. One minor and one major quantitative trait locus (QTL) were consistently mapped on linkage groups 1 and 7, respectively, both with favorable alleles contributed from IT97K-556-6. The major QTL appeared dominant based on a validation test in a related F2 population. SNP markers flanking each QTL were positioned in physical contigs carrying genes involved in plant defense based on synteny with related legumes. These markers could be used to introgress resistance alleles from IT97K-556-6 into susceptible local blackeye varieties by backcrossing.

No MeSH data available.


Related in: MedlinePlus

Chromosomal regions associated with aphid damage symptoms measured at different days after planting (DAP) in the CB27 × IT97K-556-6 RIL population grown at UC-KARE, Parlier, CA, in 2012 and 2013: a whole genome scan, b minor QTL QAc-vu1.1 on LG 1 and c major QTL QAc-vu7.1 on LG 7
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Fig3: Chromosomal regions associated with aphid damage symptoms measured at different days after planting (DAP) in the CB27 × IT97K-556-6 RIL population grown at UC-KARE, Parlier, CA, in 2012 and 2013: a whole genome scan, b minor QTL QAc-vu1.1 on LG 1 and c major QTL QAc-vu7.1 on LG 7

Mentions: Two QTLs associated with response to CPA infestation were identified using data recorded at different assay times and growing seasons (Table 1; Fig. 3). The major QTL, QAc-vu7.1, was located on linkage group 7 of the CB27 × IT97K-556-6 genetic map, explaining approximately 61–66 % of the total phenotypic variation. The minor QTL with a smaller additive effect, QAc-vu1.1, was located on linkage group 1, explaining approximately 5–13 % of the total phenotypic variation. The linkage group designations (LG 1 and LG 7) on the CB27 × IT97K-556-6 individual map are equivalent to the linkage group designations on the latest version of the cowpea consensus genetic map (Lucas et al. 2011) available at HarvEST:Cowpea (http://harvest-web.org/). Favorable alleles (low-symptom score alleles) were contributed from IT97K-556-6 at both loci. There was no epistatic interaction between two QTLs.Table 1


Genetic mapping and legume synteny of aphid resistance in African cowpea (Vigna unguiculata L. Walp.) grown in California.

Huynh BL, Ehlers JD, Ndeve A, Wanamaker S, Lucas MR, Close TJ, Roberts PA - Mol. Breed. (2015)

Chromosomal regions associated with aphid damage symptoms measured at different days after planting (DAP) in the CB27 × IT97K-556-6 RIL population grown at UC-KARE, Parlier, CA, in 2012 and 2013: a whole genome scan, b minor QTL QAc-vu1.1 on LG 1 and c major QTL QAc-vu7.1 on LG 7
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4300395&req=5

Fig3: Chromosomal regions associated with aphid damage symptoms measured at different days after planting (DAP) in the CB27 × IT97K-556-6 RIL population grown at UC-KARE, Parlier, CA, in 2012 and 2013: a whole genome scan, b minor QTL QAc-vu1.1 on LG 1 and c major QTL QAc-vu7.1 on LG 7
Mentions: Two QTLs associated with response to CPA infestation were identified using data recorded at different assay times and growing seasons (Table 1; Fig. 3). The major QTL, QAc-vu7.1, was located on linkage group 7 of the CB27 × IT97K-556-6 genetic map, explaining approximately 61–66 % of the total phenotypic variation. The minor QTL with a smaller additive effect, QAc-vu1.1, was located on linkage group 1, explaining approximately 5–13 % of the total phenotypic variation. The linkage group designations (LG 1 and LG 7) on the CB27 × IT97K-556-6 individual map are equivalent to the linkage group designations on the latest version of the cowpea consensus genetic map (Lucas et al. 2011) available at HarvEST:Cowpea (http://harvest-web.org/). Favorable alleles (low-symptom score alleles) were contributed from IT97K-556-6 at both loci. There was no epistatic interaction between two QTLs.Table 1

Bottom Line: One minor and one major quantitative trait locus (QTL) were consistently mapped on linkage groups 1 and 7, respectively, both with favorable alleles contributed from IT97K-556-6.SNP markers flanking each QTL were positioned in physical contigs carrying genes involved in plant defense based on synteny with related legumes.These markers could be used to introgress resistance alleles from IT97K-556-6 into susceptible local blackeye varieties by backcrossing.

View Article: PubMed Central - PubMed

Affiliation: Department of Nematology, University of California, Riverside, CA 92521 USA.

ABSTRACT

The cowpea aphid Aphis craccivora Koch (CPA) is a destructive insect pest of cowpea, a staple legume crop in Sub-Saharan Africa and other semiarid warm tropics and subtropics. In California, CPA causes damage on all local cultivars from early vegetative to pod development growth stages. Sources of CPA resistance are available in African cowpea germplasm. However, their utilization in breeding is limited by the lack of information on inheritance, genomic location and marker linkage associations of the resistance determinants. In the research reported here, a recombinant inbred line (RIL) population derived from a cross between a susceptible California blackeye cultivar (CB27) and a resistant African breeding line (IT97K-556-6) was genotyped with 1,536 SNP markers. The RILs and parents were phenotyped for CPA resistance using field-based screenings during two main crop seasons in a 'hotspot' location for this pest within the primary growing region of the Central Valley of California. One minor and one major quantitative trait locus (QTL) were consistently mapped on linkage groups 1 and 7, respectively, both with favorable alleles contributed from IT97K-556-6. The major QTL appeared dominant based on a validation test in a related F2 population. SNP markers flanking each QTL were positioned in physical contigs carrying genes involved in plant defense based on synteny with related legumes. These markers could be used to introgress resistance alleles from IT97K-556-6 into susceptible local blackeye varieties by backcrossing.

No MeSH data available.


Related in: MedlinePlus