Status of conservation of the indigenous leaf vegetables and fruits of Africa

The diversity of indigenous leaf vegetables and fruits of Africa is being seriously eroded as a result of multiplicity of environmental, political and socio-economic factors. This paper discusses some new development-related and crises factors that have interacted in concert to amplify the spate of loss of the indigenous leaf vegetables and fruits genetic resources in Africa. The paper also suggests urgent steps that nations individually and Africa in general can take to arrest the wave of loss of plant genetic resources and therefore ensure the conservation of our remaining indigenous leaf vegetables and fruits heritage. Key Words: Conservation, indigenous vegetables and fruits, Africa, genetic erosion. African Journal of Biotechnology Vol.3(12) 2004: 700-70

Cloning and sequence analysis of the nucleotide-binding domain of an α-glucan, water dikinase gene from cassava (Manihot esculenta Crantz)

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Seed constraint to cultivation and productivity of African indigenous leaf vegetables

Non-availability of improved seeds constitutes a major constraint to the cultivation and productivity of the indigenous leaf vegetables (ILVs) of Africa. Research on African ILVs has focused mainly on the ethnobotany, collection, preservation, and the assessment of food value and chemical composition ofthe ILVs. No serious breeding and seed production research has been done on the ILVs. This paper examines some factors underlying the lack of interest in the production of ILVs seeds, the problem associated with local seed processing and the way to organize a seed production programme for theILVs

Effect of organic and inorganic fertilizer on yield and chlorophyll content of maize (Zea mays L.) and sorghum Sorghum bicolour (L.) Moench)

The effects of amending soil with organic (poultry manure) and inorganic fertilizer on yield and chlorophyll content of maize (Zea mays L.) and sorghum (Sorghum bicolour (L.) Moench) was carried out at the Teaching and Research (T&R) Farm of the Obafemi Awolowo University, (O.A.U.) Ile - Ife, Nigeria. The experiment was a randomised complete block design (RCBD), laid out in a split-plot arrangement in the second cropping season of year 2001 and 2002. There were four sources of fertilizer for soil amendment: inorganic fertilizer (IF), mixture of inorganic fertilizer and poultry manure (IFPM), poultry manure (PM) and control (C) (no fertilizer or manure treatment). Each fertilizer source supplied 54 kg N plus 25 kg P2O5 and 25 kg K2O5/ha. There were significant variability and diversity observed on the two crops due to treatments. Grain yield was highest in sorghum (3.55 kg/ha) and maize (2.89 kg/ha) under IFPM followed by IF treatment for maize (2.33 kg/ha) and PM treatment for sorghum ((3.37 kg/ha). Sorghum and maize had the highest dry matter of 72.3 g/plant and 71.0 g/plant under IFPM at harvest. The effects of PM on the dry matter of sorghum (68.1 g/plant) and maize (61.7 g/plant) were not significantly different (p = 0.05) from that of IF (sorghum 66.1 g/plant, maize 58.7 g/plant). Sorghum also had the highest leaf area (LA) (2752.9 cm2/plant) and total chlorophyll content of 3.28 mg/g under PM while maize on the other hand had the highest LA (1969.5 cm2/plant) and total chlorophyll content of 2.63 mg/g under IFPM. In both maize and sorghum, the lowest chlorophyll content occurred in control plot. Drought tolerance measured as percentage chlorophyll stability index (CSI%) was highest under control plots in both crops

Evaluation of two contrasting cassava canopy structures on weed flora composition in a rainforest zone of Nigeria.

The impact of weed competition on crop growth is a universal concern to farmers. This study was conducted in 2010 at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife to evaluate the impact of cassava canopy on weed diversity and identify shade-tolerant weed species in response to varying canopy structure at Obafemi Awolowo University Teaching and Research Farm, Ile-Ife ecological zone. The treatments consist of hand-weeded, herbicidal treatment, and unweeded checks in the main plot. The sub-plots constituted the cassava cultivars (TMS 30572 and TME 1) laid out in a randomized complete block with a split-plot arrangement in three replications. Fifteen weed species survived under the shade of TMS 30572 where two families were monocots while four families were dicots. However, twenty weed species were recorded where TME 1 was cultivated of which two families were monocots while five families were dicots. TMS 30572 suppressed weeds by 20% when compared to TME 1. In conclusion, TME 30572 is recommended for cultivation in this agroecology to obtain a maximum benefit on cassava production. Keywords: Weed, TMS 30572, TME 1, Shade-tolerant, and Weed diversity. DOI: 10.7176/JNSR/12-12-05 Publication date:June 30th 202

A Cassava vein mosaic viruspromoter cassette induces high and stablegene expression in clonally propagated transgenic cassava(Manihot esculentaCrantz)

The study described a T-DNA vector with aCassava vein mosaic viruspromoter cassette (pCsVMV) and a kanamycin selectable marker gene driven by the 35SCauliflower mosaic viruspromoter with a view to stably express transgenes over repeated cycles of clonal propagation. Aβ-glucuronidasereporter gene under control of pCsVMV (pCsVMV-GUS) was introduced into the cassava landrace‘Tokunbo’ viaAgrobacterium-mediated genetic transformation. Transgenic tobacco plants (Nicotiana tabacumSR1) with the same gene construct were also produced. In tobacco, the pCsVMV-GUS was highly expressed in all tissues tested such as leaf, stem, petiole, and roots. In transgenic cassava, the pCsVMV-GUS gene was highly expressed in all tissues and most cell types of in vitro plants including leaf, stem, petiole, andfibrous roots. The pCsVMV-GUS gene was also highly expressed in these tissues as well as in tubers of greenhouse grown cassava. High and stable pCsVMV-GUS gene expression was maintained over 3 cycles of ratooning under greenhouse conditions, thus showing the absence of undesired gene silencing effects after repeated in vitro subculturing and vegetative propagation. From the high constitutive levels of GUS activity observed, the study concluded that the CsVMV promoter cassette was useful for high-level expression in cassava over repeated cycles of clonal propagation