Tomato (Solanum lycopersicum L.) is a major economic crop consumed globally in fresh or processed forms. During a routine field survey of major tomato-producing areas of southwestern Nigeria in May/June 2013, tomato plants cv. Roma VF showing virus-like symptoms including stunting, chlorosis, and narrowing of leaf blades were observed in 10 farmers' fields with varying levels of incidence averaging ~27%. Moderate to high aphid infestations were also observed in affected fields, and fruit production was significantly impacted based on visual observations. Since symptoms observed on affected plants are similar to those described for Cucumber mosaic virus (CMV) infection in tomato (5), leaf tissue samples collected from a total of 92 tomato plants across 10 commercial farms were subjected to antigen coated plate (ACP)-ELISA essentially as described previously (2). In ACP-ELISA using a CMV polyclonal antibody, 24 of the 92 samples (26.1%) derived from 7 of the 10 survey locations spread across Oyo, Ogun, Ekiti, and Osun states of southwestern Nigeria tested positive for CMV. Based on the ACP-ELISA results, one randomly selected sample from each of the CMV-positive survey locations, seven samples in total, was subjected to total nucleic acid extraction (1) followed by one step-single tube RT-PCR using primers CMV1/CMV2 and conditions described previously (4) with appropriate virus-positive and -negative controls. A ~500 bp DNA band was amplified from these seven ACP-ELISA-positive samples, thus confirming the presence of CMV. To further confirm these results and to enable molecular typing of CMV isolates from southwest Nigeria, the amplified DNA fragments were precipitated with the addition of 70% ethanol and centrifugation and directly sequenced using the ABI 3130xL Genetic Analyzer (Applied Biosystems, California) at the Bioscience Center of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Following the removal of primer- and 3′UTR-specific sequences, the remaining 366-bp partial CP-specific sequences (GenBank Accession Nos. KM091952 to 58) and corresponding sequences of global CMV isolates obtained from GenBank were subjected to multiple alignments using the MEGA 6.0 software. This analysis showed that tomato-infecting CMV isolates from southwest Nigeria shared 91.6 to 99.4% and 94.9 to 99.1% nucleotide (nt) and amino acid (aa) identities among themselves and 91.6 to 98.0% and 94.1 to 98.3%, 89.4 to 94.1% and 93.2 to 98.3%, and 75.2 to 78.8% and 84.0 to 87.3% with corresponding nt and aa sequences of representatives of CMV isolates belonging to subgroups IA (D10538), IB (AB008777), and II (M21464), respectively. Maximum likelihood phylogenetic analysis revealed the clustering of four and three CMV isolates obtained in this study into subgroups IA and IB, respectively, with >70% bootstrap support. CMV has been detected in tomato seeds (3) and its very wide host range includes cultivated crops and weed species (5). It is therefore plausible that contaminated seed lots and alternative weed and crop host plants serve as sources of CMV inoculum to cultivated tomato in affected farms. Although CMV has been reported from tomato from several countries worldwide, to our knowledge, this is the first empirical evidence for the occurrence of CMV subgroups IA and IB in cultivated tomato in Nigeria. References: (1) S. L. Dellaporta et al. Plant Mol. Biol. Rep. 1:19, 1983. (2) J. d'A. Hughes and S. A. Tarawali. Trop. Sci. 39:70, 1999. (3) K. H. Park and B. J. Cha. Res. Plant Dis. 8:101, 2002. (4) S. Wylie et al. Aus. J. Agric. Res. 44:41, 1993. (5) T. A. Zitter and J. F. Murphy. Plant Health Instructor. DOI: 10.1094/PHI-I-2009-0518-01, 2009.

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This study characterized Cucumber mosaic virus (CMV) infecting pepper in Southwestern Nigeria with the aim of providing up-to-date information on the taxonomic subgroup(s) of the parading strains in the study area. Fifty pepper leaf samples with one or more symptoms of mottling, mosaic, necrosis, leaf distortion and stunting were collected from eight commercial farms across Southwestern Nigeria and screened for CMV using antigen coated plate enzyme linked immunosorbent assay (ACP-ELISA). From the seropositive samples, four representative samples were selected, labelled PSWN1-4 before subjected to reverse transcription polymerase chain reaction (RT-PCR) and nucleic acid sequencing using a pair of primers specific for the amplification of RNA 3 genomic fragment of CMV. These were followed by multiple nucleotide sequence alignment and phylogenetic estimations of the isolates alongside selected CMV strains that were reported in previous studies using the molecular evolutionary genetics analysis (MEGA) software. The result of the ACP-ELISA test revealed that 14 (28%) of the samples collected were positive for CMV infection. The resulting nucleotide sequences from RT-PCR revealed 98% nucleotide homologies with several corresponding sequences of CMV strains from the Genbank. Further analysis of the PSWN nucleotide sequences through multiple nucleotide sequence alignment revealed the absence of the EcoR1 restriction site found only within the examined genomic portion of RNA 3 of subgroup II strains. These features defined the detected isolates as subgroup I strains. Phylogenetic analysis and estimations of genetic distances, conclusively distinguished the pepper-infecting CMV isolates from Southwestern Nigeria as members of subgroups IA and IB, which are the most virulent subgroups.

Digital temperature sensing sometimes suffer inaccuracy as a result of Vdd variation generating noise within a digital temperature sensor, built around ring oscillators. Thus, noise generated affects ring oscillator's frequency. In this paper, a delay-based digital temperature sensor is formulated, implemented and evaluated on a Field Programmable Gate Array Chip. The temperature sensor is realized using Very High-Speed Integrated Circuit Hardware Description Language and synthesized in Quartus II. The realized digital circuit was implemented on an Altera DE3 board with a Stratix III Field Programmable Gate Array chip. Data obtained was analysed using Least-Square interpolation method to determine the effect of voltage drop. The result is a resource efficient digital temperature sensor sensitive to variation in Vdd less than 3.3V. A measurement error of -2.3 o C~+2.1 o C was obtained at Vdd of 3.3V and -2.7 o C~+1.7 o C when Vdd equal 1.5V for a temperature range within 40 o C~120 o C.

Drosophila melanogaster is a holometabolous frugivorous fly, with neurobiological and neurogenetic modelling importance owed to its small size, short life cycle, fast reproductive rate, low cost in maintenance and small tetra-chromosomal genome. Nigella sativa (Black seed) is a widely researched medicinal plant with numerous reported therapeutic activities in humans and rodents. Being the most abundant neurotransmitter in Drosophila, glutamate plays an important role in learning and memory, neuro-excitation but also neuro-inhibition. This research thus investigated the impacts of Nigella sativa on the survival rate, glutamate level and negative geotactical abilities in Harwich strains of Drosophila melanogaster. The experimental flies were exposed to varied concentrations of Nigella sativa oil for five days. The results showed a higher survival rate, glutamate level and negative geotactic ability for the lower dose flies, while the higher Nigella sativa dose flies recorded significantly lesser values in the trio. This indicates that Nigella sativa administered at 2.4ml/4ml (60%) of feed may be lethal to the general survival and physiological functions of adult Drosophila. The lower dose however shows a high potential of improving locomotive and neurochemical activities in flies, as further studies are on to further identify the most therapeutic dose of Nigella sativa in Drosophila melanogaster, with a range suggested based on the findings of this research