Intensive cereal-legume–livestock systems in West African dry Savannas.

The dry savannas of West Africa are undergoing rapid transformation of agricultural practices owing to the rapid human and livestock population growth, increase in agricultural intensification and accelerated climate change which has increased the incidence and severity of diseases, pests and drought. The major constraints to agricultural production in the savanna include poor soil fertility, pests and diseases of crops and livestock, parasitic weeds such as Striga hermonthica, drought, and competition between crops and livestock for resources, Inadequate policies, weak institutional mechanisms, and poor linkages among farmers, and researchers prevent adoption of improved agricultural technologies that can combat these constraints. The risk of continuous cultivation on these poor and fragile soils is huge. Integrating crop and livestock production offers ways to increase production while protecting the environment. Over the years, research and development institutions have generated several agricultural technologies to alleviate the majority of the production constraints in the West African savannas. However, most development organizations use traditional extension methods that result in poor adoption of the improved technologies. The integration of crop and livestock production is particularly desirable in intensively farmed and densely populated areas with access to urban markets. Proper integration of these practices will diversify smallholder income and increase food security. Integrated genetic and natural resource management provides the keys improved eco-efficiency. This includes integrating pesticide use with cultural practices such as modified planting date and disease control; rotating/ intercropping cereals and legumes; use of pest resistant\tolerant cultivars to increase the effectiveness of pest control and reduce the need for pesticides; and improving soil fertility restoration/maintenance. Government and national institutions in West Africa are encouraged to scale-out these technologies to wider areas for increased benefit to farmers through the use of proven extension methods

Application of fast technology for analysis (FTA) for sampling and recovery of deoxyribonucleic acid (DNA) for molecular characterization of cowpea breeding lines for Striga resistance

Article purchasedStriga gesnerioides (Willd) Vatke is a significant constraint to cowpea production in the dry savannas of sub-Saharan Africa. Yield losses caused by S. gesnerioides in these regions are estimated in millions of tons annually and the prevalence of Striga soil infestation is steadily increasing. Conventional breeding efforts have developed some cowpea lines with Striga resistance as well as other important agronomic traits but it is time-consuming and difficult to pyramid favorable traits. The use of marker-assisted selection (MAS) makes it easier to select plant traits and reduce the time needed to develop new varieties. The potential of Fast Technology for Analysis (FTA) as an effective technology for sampling and retrieval of DNA from plant tissue and their subsequent molecular analysis was assessed in the laboratory. DNA was successfully recovered from the leaf tissues of cowpea pressed into the FTA® Classic card and the DNA obtained from the FTA papers was found to be suitable for molecular analysis by PCR-based techniques. The marker efficiency of Sequence Characterized Amplified Region (SCAR) marker MahSe2 and C42B was 93% in detecting SG3 resistance. This study demonstrated that the application of MAS using FTA technology has the potential to put the breeding process on a fast track and increase the efficiency of breeding activities

Inheritance of resistance to Cercospora leaf spot disease of cowpea [Vigna unguiculata (L.) Walp]

Open Access ArticleCercospora leaf spot (CLS) caused by Pseudocercospora cruenta (Sacc.) is an important disease affecting cowpea production in Nigeria. Understanding the genetic nature of CLS is an important step in developing an effective breeding strategy. This study investigated the inheritance of CLS disease in cowpea under natural epiphytotic field condition involving two CLS resistant parents (IT99K-573-1-1, IT99K216-24) and a CLS susceptible parent (UAM09-1055-6). The parental lines, F1, BC1P1, BC1P2, F2 and F3 generations were used to study the genetic nature and to detect SSR markers closely linked with the CLS resistance gene(s) using bulked segregant analysis (BSA). The result showed that F1 populations involving UAM09-1055-6 × IT99K-573-1-1 and UAM09-1055-6 × IT99K-216-24 were resistant to CLS in the 2 crosses suggesting the presence of gene dominance in the control of the disease. The observed segregating ratio of F2 populations fits the Mendalian ratio 3:1. The plants reaction to the disease in the backcross progeny test involving the resistant parent were all uniformly resistant, whereas those involving the susceptible parent segregated into ratio 1:1. The F3 generations, which segregated into ratio 1:2:1 further confirmed that resistance was controlled by a single dominant gene in the crosses studied. Heritability estimates varied from 81 to 97%. BSA showed that SSR marker code named RB24 of lima bean and validated on F2 population discriminated between resistance and susceptibility to CLS. Hence RB24 could be a useful marker for marker-assisted selection in CLS resistance breeding in cowpea

Performance of semideterminate and indeterminate cowpeas relaycropped into maize in Northeast Nigeria

Field trials were conducted in 2005 and 2006 in Tilla (northern Guinea savanna) and Sabon-Gari (Sudan savanna) in northeast Nigeria to determine the performance of two improved cowpea varieties when relay-intercropped with early and late maize, 6 and 8 weeks after planting the maize. Grain yield, number of branches and number of pods per plant were higher for the variety IT89KD-288 than for IT97K-499-35, whether planted sole or relay-intercropped with maize. Grain yield was lower for IT97K-499-35 than for IT89KD-288 when relay-intercropped with maize irrespective of the maturity period of the companion maize crop. This may be due to the indeterminate growth habit and shade tolerance of IT89KD-288 which allowed a higher pod load than IT97K-499-35. However, relay-intercropping with early maize gave higher yield than relay-intercropping into late maize. Also relay-intercropping at 6 weeks after planting maize (WAP) gave a higher yield than relay-intercropping at 8 WAP. This therefore, suggests that introducing cowpea into short statured early maize may mean less competition for light and soil resources compared to taller late maize. Also introducing the cowpea earlier may allow the crop to make full use of soil moisture during the cropping season

Decolonization: The Litmus Test of the Human Rights Framework

This literature review examines the complicated relationship between anticolonial activism and the human rights framework that emerged in the wake of the Second World War. I contextualize the scholarly debate on the tension between conceptions of human rights as an individual entitlement and the collectivist nature of African anticolonial struggles. The universalism of the human rights framework endures the harsh light of critique, given its emergence from the twentieth-century European experience of genocide and great powers’ competing commitments to democracy and empire. The crimes against humanity committed in the name of colonial conquest and rule challenge the great powers’ moral authority as arbiters of human rights. Varied contexts of anticolonial struggle, from Algeria to Cameroon, offer different answers to the question of the efficacy and applicability of the human rights framework. Ultimately, I look to indigenous praxis and epistemology as paths to liberation that is not merely nominal

Nature of ergastic substances in some Nigerian asteraceae

Seeds of 110 species of the Nigerian Asteraceae were examined for fats and oils, proteins and starch using standard detection procedures. All the examined species except for 8 species were herbs. Fats and oils were found in all the species investigated comprising of both herbs and shrubs(100% detection rate). Protein bodies were found in 23 species. While starch grains were found to be absent in all the investigated species. There was no correlation between life forms and the nature of ergastic substances in the family. The results from this study did not support the changes of names in the revision of the tribe Vernonieae as such this character cannot be used as a delimiting species.Keywords: Ergastic substances, Shrubs, Herbs, Asteraceae

Amino acid Profile of Trichosantes cucumerina from four Geopolitical Zones in Nigeria.

Abstract The aim of the study was to investigate the amino acid profile of five (5) ecotypes of T. cucumerina (snake gourd) from four geopolitical zones in Nigeria. Fresh ripe fruit of T. cucumerina was collected from the research farm of Michael Okpara University of Agriculture, Umudike, Umuahia Abia State Nigeria. The seeds were extracted from the fresh ripe fruit, blended and stored in the refrigerator for further use. Amino acid was determined using HPLC apparatus. Glutamate had the highest protein content which ranged from 14.4643-15.23094g/100 of protein; followed by aspartate with 2.0981-12.20628g/100 of protein, leucine with 7.20846-8.9831g/100 of protein. Glycine protein was the least with a ranged of 0.0435-4.2118g/100. The snake gourd amino acid profile was found highest in North-Central ecotype (Benue State) with a ranged of (1.115-14.46497) g/100 protein; followed by South-West ecotype (Ekiti and Osun States) with a range of (0.87481-12.20628), (0.0435-15. 23094) g/100protein respectively. South- East ecotype (Abia State) T.cucumerina result ranged from (0.54978-14.67031)g/100 protein. The least result was found in South-South ecotype snake gourd with 0.35514-14.46243g/100 protein. Variation in amino acid content in ripe fruits of T. cucumerina accessions investigated revealed that glycine had the highest coefficient variation of 140% followed by tyrosine with 54.31%, aspartate 47.56%, and least from valine 5.62%, isoleucine 7.05%, tryptophan 6.51% and cysteine 6.82% glutamate 2.14%. There were three clusters in the dendrogram of amino acid composition of selected snake tomato ecotypes investigated.  Amino acid result revealed that the highest amino acid content was found in snake gourd from the North -Central and least in South-South ecotype respectively. Keywords: Amino acid, Trichosanthes cucumerina, Ecotypes, South-East, South-South, South-West and North Central

Returns to physician human capital: Evidence from patients randomized to physician teams

Physicians play a major role in determining the cost and quality of healthcare, yet estimates of these effects can be confounded by patient sorting. This paper considers a natural experiment where nearly 30,000 patients were randomly assigned to clinical teams from one of two academic institutions. One institution is among the top medical schools in the U.S., while the other institution is ranked lower in the distribution. Patients treated by the two programs have similar observable characteristics and have access to a single set of facilities and ancillary staff. Those treated by physicians from the higher ranked institution have 10–25% less expensive stays than patients assigned to the lower ranked institution. Health outcomes are not related to the physician team assignment. Cost differences are most pronounced for serious conditions, and they largely stem from diagnostic-testing rates: the lower ranked program tends to order more tests and takes longer to order them

Genetic variability and heritability studies of some reproductive traits in cowpea (Vigna unguiculate (L.) Walp.)

The success of most crop improvement programs largely depends upon the genetic variability and the heritability of desirable traits. The magnitude and type of genetic variability help the breeder to determine the selection criteria and breeding schemes to be used for improvement purposes. A screen house experiment was carried out at Samaru, Nigeria in 1999 and 2000 dry seasons to estimate the genotypic variability of some reproductive traits and their heritability in some selected cowpea varieties. Results of the study showed that there was considerable variation among cultivars for duration of reproductive phase and rate of photosynthate partitioning. Genotypic coefficients of variation were also high for days to first flower, 100-seed weight, plant height, and harvest index. Broad-sense heritability estimate (h2) was 98.9% for 100-seed weight, 94% for duration of reproductive phase, 84.5% for days to first flower, 83.9% for days to maturity, and 77.3% for harvest index. This information showed that there is sufficient genetic variance to warrant selection for improvement in the cowpea genotypes studied. We concluded that considerable progress in cowpea breeding could be achieved by exploiting these traits

Suitability and use of two molecular markers to track race-specific resistance striga gesnerioides in cowpea (Vigna unguiculata (L.) Walp.)

The obligate root parasitic weed Striga gesnerioides poses a severe constraint to cowpea productivity in the dry savannahs of West and Central Africa, where cowpea is a major crop. At least seven races of S.gesnerioides have been identified within the cowpea-growing regions of West and Central Africa, based onhost differential response and genetic diversity analysis. Molecular markers linked to resistance to  different races of S. gesneriodes have been identified. It was desirable to demonstrate the applicability and efficiency for use in marker-assisted selection (MAS) to fast-track the development of cowpea for resistance to S. gesnerioides. The objective of the study was to determine the suitability of two molecular markers in tracking race-specific S. gesnerioides resistance in cowpea (SG3), the predominant race found in Nigeria. F2 mapping populations and recombinant inbred lines (RILs) derived from the cross involving IT97K-499-35 and a susceptible local landrace (Borno Brown), and another resistant parent B301 with the same susceptible land race (Borno Brown) were assayed using two linked markers. Genetic analysis showed that resistance to S. gesnerioides in cowpea is qualitatively inherited with single dominant gene action. Two SCAR markers, 61RM2 and C42-2B were validated in the same F2 populations and subsequent recombinant inbred lines (RILs). The two markers were able to discriminate between resistance and susceptibility and the genotypic score was quite similar to the phenotypic score with the markers score showing greater efficiency in selection than phenotypic score. The 61RM2 had two bands in resistant cultivars and amplified a ~450 bp fragment with marker efficiency of 98% while C42-2B amplified a single ~250 bp fragment with marker efficiency of 96% in resistant cultivars and absent in susceptible cultivars. The genetic distance between 61RM2 and phenotypic score was 3.5 cM while that of C42-2B and phenotypic score was 8.5 cM. The two marker data set were significantly correlated with the phenotypic data (r=0.95). Based on the tight linkage with the resistant locus, 61RM2 was found to be a utility marker to initiate MAS in cowpea breeding for resistance to S. gesnerioides.Key words: Cowpea, Striga, molecular marker, genetic distance, race-specific, obligate parasitic weed, Vigna unguiculata