Field screening of cassava (Manihot esculenta Crantz) germplasm for desirable traits by the use of augmented design

Ninety-eight cassava accessions were grown in augmented randomized complete block design to screen for superior clones with desirable traits. The desirable traits were root number (RTNO), fresh root yield (FYLD), harvest index (HI), dry matter (DM), cyanide potential (CNP), mean plant height (MPHT) and level of branching (LOBR). Three standard varieties were used, namely 30572, 91/01730 and 91/023227. Acessions that were superior to the standard types in more than one trait were 92/0681, 92/02325; 92/0455, 88/02555; Alice Local and 88/02555. These accessions could be selected and put into crossing blocks to combine the traits into one genotype. The present results show that augmented designs are efficient in the identification of superior cassava genotypes with desirable traits

Determination of some mineral components of wowpea (Vigna unguiculata (L.) Walp) Using instrumental neutron activation analysis.

Some mineral elements in the seeds of the cowpea were determined using instrumental neutron activation analysis. The cowpea cultivars were made up of improved varieties (Soronko, Gbeho, Ayiyi, Asontem, Asontem1, Bengpla, Asetenapa and Adom), farmers’ accessions (87/7, 87/1, 87/27, 87/147, 87/34, 87/49, 87/83, 87/157, 87/149, 87/30, 87/153, 96/046, 87/137, 96/129, BTB 96/091, OAA 96/30, BTB 96/054), and experimental materials (IT870-677-2, Caroni, Kaase Market, 1977 and 1239). A total of 14 elements (Al, Ca, Mg, V, Mn, Br, Cl, K, Na, Zn, Cu, Ta, Si andIn) were detected in the seeds of the 30 cowpea cultivars. Five of the elements (Na, K, Mg, Ca and Cl) identified are classified as major elements in the human body, while four (Mn, Zn, V, Si, Cu and I) are trace elements. The major elements K, Na, Ca, Mg and Cl were detected in high concentration in cultivars 96/129, 87/137, Ayiyi, 87/34 and 87/49, respectively. The trace elements Mn, Zn, V, Si, Cu and Al were detected in high concentration in cultivars 87/34, 87/27, 87/34, Bengpla, 87/34 and 87/34, respectively. From the results the following accessions could beselected and incorporated into a cowpea mineral nutritional improvement programme: 96/129, 87/137, Ayiyi, 87/34, 87/49 and 87/27. The presence of the five major elements and the trace elements indicates that cowpea has a rich source of mineral elements and, therefore, can be used to improve the diet of both humans and livestock

Use of Linear Discriminant Function Analysis in Five Yield Sub-Characters Relationship Study in 134 Cowpea (Vigna unguiculata (L.) Walp) Accessions

Variations in five yield sub-characters of cowpea in 134 accessions were studied. Data were collected on number of pods per plant, pod length, pod width, peduncle length and 100-seed weight. Differences among the accessions were significant based on four of the five characters, namely pod length, pod width, peduncle length and 100-seed weight. K-means cluster analysis grouped the 134 accessions into four distinct groups. Pairwise Mahalanobis 2 distance (D) among some of the groups was highly significant. From the study the yield sub-characters pod length, pod width, peduncle length and 100-seed weight contributed most to group separation in the cowpea accessions

Phenotypic and seed protein analysis in 31 Lima bean (Phaseolus lunatus) accessions in Ghana

Phenotypic and seed protein analyses were performed on 31 accessions of Lima bean assembled in Ghana. Data on 16 phenotypic characters consisting of eight quantitative and eight qualitative were analysed. There were significant differences among the accessions based on the eight quantitative characters. Seed protein analysis showed 17 bands with relative mobility of bands, which ranged from 0.01 to 0.86. An ordinal logistic regression analysis showed significant evidence for seed coat, pod beak shape and seed size association. Cluster analysis based on both phenotypic and protein data provided evidence for differences among the accessions. Quantitative characters were associated with some specific clusters

Evaluation of geospatial methods to generate subnational HIV prevalence estimates for local level planning

Objective: There is evidence of substantial subnational variation in the HIV epidemic. However, robust spatial HIV data are often only available at high levels of geographic aggregation and not at the finer resolution needed for decision making. Therefore, spatial analysis methods that leverage available data to provide local estimates of HIV prevalence may be useful. Such methods exist but have not been formally compared when applied to HIV. Design/methods: Six candidate methods – including those used by the Joint United Nations Programme on HIV/AIDS to generate maps and a Bayesian geostatistical approach applied to other diseases – were used to generate maps and subnational estimates of HIV prevalence across three countries using cluster level data from household surveys. Two approaches were used to assess the accuracy of predictions: internal validation, whereby a proportion of input data is held back (test dataset) to challenge predictions; and comparison with location-specific data from household surveys in earlier years. Results: Each of the methods can generate usefully accurate predictions of prevalence at unsampled locations, with the magnitude of the error in predictions similar across approaches. However, the Bayesian geostatistical approach consistently gave marginally the strongest statistical performance across countries and validation procedures. Conclusions: Available methods may be able to furnish estimates of HIV prevalence at finer spatial scales than the data currently allow. The subnational variation revealed can be integrated into planning to ensure responsiveness to the spatial features of the epidemic. The Bayesian geostatistical approach is a promising strategy for integrating HIV data to generate robust local estimates

Genetic structure and bottleneck studies at the malate dehydrogenase and phosphoglucoisomerase (Glucose-6-phosphate isomerase) gene loci of neem (Azadirachta indica)

Genetic structure of the neem at the malate dehydrogenase and phosphoglucoisomerase (glucose-6-phosphate isomerase) gene loci wasstudied in a total of 192 seedlings raised from seeds collected from eleven maternal plants. Both loci were polymorphic and the mean number of alleles per locus was 5.05 + 0.54. Mean observed was 0.902 + 1.4. Levene’s and Nei’s expected heterozygosities were 0.804 + 0.02 and 0.801 + 0.02, respectively. Wright’s fixation index Fis estimates were negative for all the six alleles for the Mdh locus while for the Pgi locus the estimate was positive for two of the alleles. Analysis of molecular variance (AMOVA) indicated that 17.8 per cent of the total genetic diversity resided among families. The results showed that there was low level of population structure in the neem sample studied at the Mdh and Pgi gene loci and that the 11 families approximate a single panmictic unit. A normal ‘L’ shaped distribution of mode-shift test and three heterozygote excess tests suggested that there was no recent bottleneck in the population of neem at the two enzyme gene loci

Allozyme variation and ecogeographical variation correlation in cowpea (Vigna unguiculata(L) Walp)

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