Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 10 of 10
Full-Text Articles in Beef Science
Molecular Mapping Of Qtls For Domestication-Related Traits In Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko
Molecular Mapping Of Qtls For Domestication-Related Traits In Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko
All Peer-Reviewed Publications
Understanding the genetic basis underlying domestication-related traits (DRTs) of cowpea (Vigna unguiculata (L.) Walp.) is important since the genome has experienced divergent domestication and in addition it is also useful to utilize the wild germplasm efficiently for improving different traits of the cultivated cowpea. Quantitative trait loci (QTLs) for DRTs were identified in a population of 159 F7 recombinant inbred lines derived from a cross between a domesticated cowpea (V. unguiculata (L.) Walp.) variety, 524B, and a wild accession, 219. Using the constructed linkage map, QTLs for 10 DRTs were analysed and mapped. QTLs for seed, pod and flower related …
Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko
Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko
All Peer-Reviewed Publications
Cowpea (Vigna unguiculata (L.) Walp.) is a grain legume commonly grown and consumed in many parts of the tropics and subtropics. A genetic linkage map was constructed using simple sequence repeat (SSR) markers and a recombinant inbred (RI) population of159 individuals derived from a cross between the breeding line 524B, a California Blackeye, and 219-01, a perennial wild cowpea from Kenya. Out of 912 primer combinations predicted to amplify SSRs in cowpea, 639 reliably produced amplification products in PCR assays and 202 (31.6%) were polymorphic between the two parents. These polymorphic SSRs were used to construct a genetic map consisting …
Development Of Pcr-Based Chloroplast Dna Markers That Characterize Domesticated Cowpea (Vigna Unguiculata Ssp. Unguiculata Var. Unguiculata) And Highlight Its Crop-Weed Complex, Y. Feleke, R. S. Pasquet, P. Gepts
Development Of Pcr-Based Chloroplast Dna Markers That Characterize Domesticated Cowpea (Vigna Unguiculata Ssp. Unguiculata Var. Unguiculata) And Highlight Its Crop-Weed Complex, Y. Feleke, R. S. Pasquet, P. Gepts
All Peer-Reviewed Publications
In 1992, Vaillancourt and Weeden discovered a very important mutation for studying cowpea evolution and domestication. A loss of a BamHI restriction site in chloroplast DNA characterized all domesticated accessions and a few wild (Vigna unguiculata ssp. unguiculata var. spontanea) accessions. In order to screen a larger number of accessions, primers were designed to check this mutation using PCR RFLP or direct PCR methods. Using these new primers, 54 domesticated cowpea accessions and 130 accessions from the wild progenitor were screened. The absence of haplotype 0 was confirmed within domesticated accessions, including primitive landraces from cultivar-groups Biflora and Textilis, suggesting …
Genetic Diversity In Cowpea [Vigna Unguiculata (L.) Walp.] As Revealed By Rapd Markers, Fana Sylla Ba, Remy S. Pasquet, Paul Gepts
Genetic Diversity In Cowpea [Vigna Unguiculata (L.) Walp.] As Revealed By Rapd Markers, Fana Sylla Ba, Remy S. Pasquet, Paul Gepts
All Peer-Reviewed Publications
The present study, using RAPD analysis, was undertaken to characterize genetic variation in domesticated cowpea and its wild progenitor, as well as their relationships. The materials used consisted of 26 domesticated accessions, including accessions from each of the five cultivar-group, and 30 wild/weedy accessions, including accessions from West, East and southern Africa. A total of 28 primers generated 202 RAPD bands. One hundred and eight bands were polymorphic among the domesticated compared to 181 among wild/weedy cowpea accessions. Wild accessions were more diverse in East Africa, which is the likely area of origin of V. unguiculata var. spontanea. Var. spontanea …
Genetic Relationships Among Subspecies Of Vigna Unguiculata (L.) Walp. Based On Allozyme Variation, R. S. Pasquet
Genetic Relationships Among Subspecies Of Vigna Unguiculata (L.) Walp. Based On Allozyme Variation, R. S. Pasquet
All Peer-Reviewed Publications
The cowpea [Vigna unguiculata (L.) Walp.] is a morphologically and genetically variable species composed of wild perennial, wild annual, and cultivated forms that are mainly used for edible seeds and pods. In this study, genetic variation in 199 germplasm accessions of wild and cultivated cowpea was evaluated using an allozyme analysis. The results from this survey showed that wild cowpea exhibits genetic variation perfectly fitted with the existing morphological classification. The cowpea gene-pool is characterized by its unusually large size. It encompasses taxa (ranked as subspecies) that could be considered as different species considering the high genetic distances observed between …
Morphological Study Of Cultivated Cowpea Vigna Unguiculata (L.) Walp. Importance Of Ovule Number And Definition Of Cv Gr Melanophthalmus, Rémy Stéphane Pasquet
Morphological Study Of Cultivated Cowpea Vigna Unguiculata (L.) Walp. Importance Of Ovule Number And Definition Of Cv Gr Melanophthalmus, Rémy Stéphane Pasquet
All Peer-Reviewed Publications
More than 400 cultivated cowpea accessions were studied using 29 morphophysiological characters. The analysis of data contrasts evolved cultivars and more primitive cultivars (and wild forms) according to seed size on the one hand and early and late flowering (under inductive conditions) on the other hand. The latter character is markedly correlated with ovule number. Photosensitive and early-flowering photoindependent cultivars have 11-17 ovules per pod and late flowering photoindependent cultivars have 16-25 ovules per pod. The analysis leads to assigning the accessions studied to the following different cultigroups: cv gr Unguiculata, cv gr Sesquipedalis, cv gr Biflora and cv gr …
Neem Seed Extract Spray Applications As Low-Cost Inputs For Management Of The Flower Thrips In The Cowpea Crop, R. C. Saxena, E. L. Kidiavai
Neem Seed Extract Spray Applications As Low-Cost Inputs For Management Of The Flower Thrips In The Cowpea Crop, R. C. Saxena, E. L. Kidiavai
All Peer-Reviewed Publications
In field trials conducted at the Experiment Station and in a farmer's field at Mbita near the shores of Lake Victoria, Kenya, applications of 2% or 3% neem seed extract (NSE) @ 200 l/ha with a knapsack sprayer at 38, 47 and 51 days after emergence (DE) of the cowpea crop or 5%, 10% or 20% NSE sprayed @ 10 l/ha with an ultra-low-volume applicator at 31, 39 and 49 DE often significantly reduced the number of larvae of the flower thrips, Megalurothrips sjostedti (Trybom), in cowpea flowers recorded 2 days after each treatment. Also fewer adults occurred in flowers …
Genetics Of Resistance To Aphis Craccivora In Cowpea, S. M. Githiri, K. Ampong-Nyarko, E. O. Osir, P. M. Kimani
Genetics Of Resistance To Aphis Craccivora In Cowpea, S. M. Githiri, K. Ampong-Nyarko, E. O. Osir, P. M. Kimani
All Peer-Reviewed Publications
Inheritance of aphid resistance and allelic relationships among sources of resistance was studied in the parents, F1, F2, F3, and backcross populations of cowpea crosses. Each 4-day old seedling was infested with five fourth-instar aphids. Seedling reaction was recorded 14-16 days after infestation when the susceptible check was killed. The segregation data from eight crosses between resistant and susceptible cowpea cultivars indicated that aphid resistance was inherited as a monogenic dominant trait. Segregation data from crosses among eight resistant cultivars indicated that one or two loci and modifier(s) were involved in the expression of resistance to aphids. It was suggested …
Linkage Relationships Among Loci Controlling Morphological Traits In Cowpea (Vigna Unguiculata (L.) Walp.), S. M. Githiri, P. M. Kimani, R. S. Pathak
Linkage Relationships Among Loci Controlling Morphological Traits In Cowpea (Vigna Unguiculata (L.) Walp.), S. M. Githiri, P. M. Kimani, R. S. Pathak
All Peer-Reviewed Publications
Linkage among loci controlling various morphological traits in cowpea were determined using F2 progenies. Data were collected on individual plants of four crosses segregating for several loci. Recombination estimates between the following pairs of loci were as follows: Sw (swollen vs normal stem base)-Fbc (cream vs green flower buds) (41±4.8%), Pus(purple vs green stems)-Cbr (cocoa-brown vs straw-yellow dry pods) (31±5.7%), Pup(purple vs green immature pods)-Cbr (30±5.7%), Pus-Pup (4±1.5%), Ndt (non-determinate vs determinate)-Pd (peduncle colour) (26±2.8%), Ndt-Hg (semi-erect vs erect plant type) (26±2.8%), Pt(purple vs green pod tips)-Bk (greyish-black vs straw-yellow dry pods) (19±2.4%) and Hg-Bpd (normal vs branching peduncle (24±9.5%). …
Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe
Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe
All Peer-Reviewed Publications
Pubescence (trichomes) in wild and cultivated cowpeas, Vigna vexillata and V. unguiculata, adversely affected oviposition, mobility, and food consumption and utilisation by the legume pod borer, Maruca testulalis (Geyer), in tests conducted with TVnu 72 (wild, highly resistant and highly pubescent), TVu 946 (semi-wild, moderately resistant and pubescent) and IT82D-716 (cultivated, highly susceptible and pubescent). In free-choice and no-choice tests, significantly (P < 0.05) fewer eggs were laid on 3-week-old potted plants of TVnu 72, the highly pubescent and wild species; this species also received fewer eggs on abaxial and adaxial leaf surfaces. Ovipositional activity on stipules, stem, branches, terminal shoots, adaxial and abaxial leaf surfaces of the susceptible cultivar, IT82D-716 was higher (P < 0.05) than on TVu 946 and TVnu 72. More eggs were laid on the abaxial surfaces than on the adaxial surfaces of leaves for all tests conducted, except for the TVnu 72 no-choice test. Significant negative correlations (r = -0.99** and r = -0.99**) were found between mean number of eggs laid and length and density of non-glandular trichomes. There was a significant negative correlation (r = -0.99**) between larval velocity and length of non-glandular trichomes on pod surface. Similarly, significant negative correlations (r = -0.85* and -0.89*) were found between larval velocity and density and length of non-glandular trichomes on leaf surface. Pods of IT82D-716 and TVnu 72 were the most - and least - preferred for settling by larvae of M. testulalis, respectively. There was a significant positive correlation (r = 0.99**) between larval penetration time on pods and length of non-glandular trichomes. Weight loss, number of feeding punctures and number of larvae on whole pods of TVnu 72 were lower and significantly different (P < 0.05) from IT82D-716 and TVu 946. This study showed that it would be advantageous to use TVnu 72 in a breeding programme to incorporate pubescence into high-yielding commercial cultivars for resistance against M. testulalis and possibly other major pests. © 1995.