Selfmonitoring of blood glucose practices by people living with diabetes who use their personal glucometers in Port Harcourt, Niger Delta Region, Nigeria

Self-monitoring of blood glucose (SMBG) assists persons living with diabetes with the day-to-day behavioral and therapeutic adjustments to their diabetes care. It is a cheaper and more available alternative to glycated haemoglobin (HbA1c) in Nigeria for monitoring glycaemic control. Information on SMBG practices of Nigerians living with diabetes using their personal glucometers is scanty. The aim of the study is to assess the intensity and frequency of SMBG by glucometer owners, and the extent the patients and/or the health care providers (HCP) utilize SMBG to achieve personalized treatment goals via behavioral/treatment adjustments. This was a cross sectional study carried out among persons living with diabetes that accessed diabetes care at the diabetes clinic of the University of Port Harcourt Teaching Hospital (UPTH) and using their personal glucometers. They were consecutively recruited. Data obtained by using intervieweradministered questionnaires were analyzed using SPSS version 20.0, and pvalue <0.05 was considered significant. A total of 128 persons living with diabetes participated in the study of which 40 (31%) were males and 88 (69%) were females; the mean age of the subjects was 52.05 ± 11.24 years with a range of 26–70 years. The majority of the study subjects (72%) were in the active working age group (25–60years). The highest frequency of glucometer use was in the 26 subjects (20%) who checked their blood glucose every morning while 62 (48%) of the subjects checked their blood glucose any morning they felt like. Most of the subjects (60%) did not have any recording device. Glucometer owners were not just the insulin-requiring people living with diabetes as more than half of the subjects, 66 (52%) were on oral anti diabetic drugs (OAD) only. Glucometer ownership was mainly by those that were in the working age group. SMBG protocol (frequency) was variable and SMBG data were not maximally utilized.Keywords: Self-monitoring of blood glucose; Personal glucometer; Diabetes; Blood glucos

Genetic gains in yield and yield related traits under drought stress and favorable environments in a maize population improved using marker assisted recurrent selection

The objective of marker assisted recurrent selection (MARS) is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY) in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S1 lines from each of the three selection cycles (C0, C1, C2) of the MARS population, parental testcrosses and the cross between the two parents (F1) were evaluated under drought stress (DS) and well watered (WW) well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S1 lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP) markers. Testcrosses derived from C2 produced significantly higher grain field under DS than those derived from C0 with a relative genetic gain of 7% per cycle. Also, the testcrosses of S1 lines from C2 showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C0 to 0.515 at C2, while the effective number of alleles (Ne) per locus decreased from C0 (1.93) to C2 (1.87). Our results underscore the effectiveness of MARS for improvement of GY under DS condition

Genetic diversity and population structure of Striga hermonthica populations from Kenya and Nigeria

Article purchasedStriga hermonthica is a parasitic weed that poses a serious threat to the production of economically important cereals in sub-Saharan Africa. The existence of genetic diversity within and between S. hermonthica populations presents a challenge to the successful development and deployment of effective control technologies against this parasitic weed. Understanding the extent of diversity between S. hermonthica populations will facilitate the design and deployment of effective control technologies against the parasite. In the present study, S. hermonthica plants collected from different locations and host crops in Kenya and Nigeria were genotyped using single nucleotide polymorphisms. Statistically significant genetic differentiation (FST = 0.15, P = 0.001) was uncovered between populations collected from the two countries. Also, the populations collected in Nigeria formed three distinct subgroups. Unique loci undergoing selection were observed between the Kenyan and Nigerian populations and among the three subgroups found in Nigeria. Striga hermonthica populations parasitising rice in Kenya appeared to be genetically distinct from those parasitising maize and sorghum. The presence of distinct populations in East and West Africa and in different regions in Nigeria highlights the importance of developing and testing Striga control technologies in multiple locations, including locations representing the geographic regions in Nigeria where genetically distinct subpopulations of the parasite were found. Efforts should also be made to develop relevant control technologies for areas infested with ‘rice-specific’ Striga spp. populations in Kenya

Genetic diversity and population structure of maize inbred lines with varying levels of resistance to striga hermonthica using agronomic trait-based and SNP markers

Open Access Journal; Published online: 17 Sept 2020Striga hermonthica is a serious biotic stress limiting maize production in sub-Saharan Africa. The limited information on the patterns of genetic diversity among maize inbred lines derived from source germplasm with mixed genetic backgrounds limits the development of inbred lines, hybrids, and synthetics with durable resistance to S. hermonthica. This study was conducted to assess the level of genetic diversity in a panel of 150 diverse maize inbred lines using agronomic and molecular data and also to infer the population structure among the inbred lines. Ten Striga-resistance-related traits were used for the phenotypic characterization, and 16,735 high-quality single-nucleotide polymorphisms (SNPs), identified by genotyping-by-sequencing (GBS), were used for molecular diversity. The phenotypic and molecular hierarchical cluster analyses grouped the inbred lines into five clusters, respectively. However, the grouping patterns between the phenotypic and molecular hierarchical cluster analyses were inconsistent due to non-overlapping information between the phenotypic and molecular data. The correlation between the phenotypic and molecular diversity matrices was very low (0.001), which is in agreement with the inconsistencies observed between the clusters formed by the phenotypic and molecular diversity analyses. The joint phenotypic and genotypic diversity matrices grouped the inbred lines into three groups based on their reaction patterns to S. hermonthica, and this was able to exploit a broad estimate of the actual diversity among the inbred lines. The joint analysis shows an invaluable insight for measuring genetic diversity in the evaluated materials. The result indicates that wide genetic variability exists among the inbred lines and that the joint diversity analysis can be utilized to reliably assign the inbred lines into heterotic groups and also to enhance the level of resistance to Striga in new maize varieties

Genetic diversity and population structure of a mini-core subset from the world cowpea (Vigna unguiculata (L.) Walp.) germplasm collection

Open Access Journal; Published online: 30 Oct 2018The International Institute of Tropical Agriculture maintains the world’s largest collection of cowpea germplasm of over 15,000 accessions. A sub-set of 298 lines from the loosely composed mini core collection of 370 landraces were genotyped based on genotyping by sequencing (GBS). Ward’s minimum variance hierarchical cluster analysis, model-based ancestry analysis and discriminant analysis of principal component (DAPC) were carried out on this sub-set. Three clusters were identified by the different clustering methods. Principal component analysis further supported the three clusters especially when accessions are scattered along the axes of the first two principal components. The first two principal components explained a total of 22.30% of the variation. Cluster one comprises 115 accessions from the largest number of countries and has the highest gene diversity, heterozygosity and polymorphic information content (PIC) values. Cluster two is made up of 102 accessions, 90 percent of which are from West and Central Africa. Analysis of molecular variance shows that the most variation is among accessions and lowest among clusters. No cluster is made exclusively of accessions from a single country. Based on SNP markers, the sub set of cowpea mini core germplasm collection used in this study encompasses the diversity in the crop

Genetic diversity of Striga hermonthica (Del.) benth. weeds from Nigeria and Kenya, and the genetic responses of selected hist maize lines

IITA supervisor: Dr. Gedil, M.Striga hermonthica (SH) is a parasitic weed that attacks and significantly reduces the yield of maize in Africa. The genetic interactions responsible for resistance or susceptibility of hosts to the parasite and the genetic differentiation that exists between and within SH populations are not fully known. This study investigated the genetic diversity of SH populations in the largest maize producers in Sub-Saharan Africa (Kenya and Nigeria) and; the genetic responses of a susceptible (5057) and a resistant (ZD05) maize genotype to SH infestation. The SH plants were collected from farms across western Kenya (KSH) and northern Nigeria (NSH) in October 2012 and authenticated at the Department of Botany, University of Ibadan (UIH-22774). The plants (n=1029) were then genotyped with 1576 single nucleotide polymorphism markers and indices of genetic diversity [effective alleles (Ne), Shannon’s information index (I), expected (He) and observed heterozygosity (Ho)] were determined. Population structure and fixation index (Fst), were assessed to identify genetic differentiation between and within KSH and NSH populations. Two maize varieties (5057 and ZD05) were divided into four groups of nine plants each and planted in rhizotrons (root observation chambers). Seven days after planting, three groups of each maize genotype were infested with pre-germinated SH and the fourth was used as uninfested control. Root tissue was taken at 3, 9 and 22 days post infestation (DPI) and total ribonucleic acid ( ribonucleic acid ( ribonucleic acid (ribonucleic acid (ribonucleic acid (ribonucleic acid ( ribonucleic acid (RNA) was extracted using standard method. The root transcriptome was sequenced using next-generation sequencing. Gene expression levels of secondary metabolism, of secondary metabolism, of secondary metabolism, of secondary metabolism, of secondary metabolism, of secondary metabolism, of secondary metabolism, of secondary metabolism, defence defence defence defence, and , and , and antiapoptotic genes antiapoptotic genes antiapoptotic genes antiapoptotic genes antiapoptotic genes antiapoptotic genes antiapoptotic genes antiapoptotic genes were determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and determined by profiling the messenger RNA levels and comparing the logcomparing the log comparing the log comparing the log comparing the log 2 fold-change (LFC) between the infested and uninfested maize plants and between the genotypes. Data were analysed using two-way ANOVA at α0.05. The two populations of SH displayed high levels of genetic diversity. KSH showed higher levels (Ne=1.41±0.01, I=0.38±0.01, Ho=0.28, He=0.25±0.0) than NSH (Ne=1.41±0.01, I=0.332±0.01, Ho=0.21, He=0.20±0.00). Significant genetic differentiation (Fst=0.15) was observed between the two populations and between three subpopulations detected within the NSH population (Fst =0.053). At 3DPI, secondary metabolism and defence genes, benzoxazineless 1 (LFC=2.5) and chalcone synthase 2 (LFC=3.2), were upregulated in ZD05, while in 5057, antiapoptotic genes, bax inhibitor1 (LFC=1.4) and bcl-2 binding anthanogene-1 (LFC=1.7) were upregulated. At 9DPI, secondary metabolism and defence genes, chalcone synthase (LFC=-1.7) and cellulose synthase (LFC=-1.7), were downregulated in 5057, while secondary metabolism and defence genes, chalcone isomerase (LFC=2.3), cellulose synthase (LFC=1.5), chitinase (LFC=1.6) and phenylalanine ammonia-lyase1 (LFC=1.8) were upregulated in ZD05. At 22 DPI, secondary metabolism and defence genes, chalcone synthase (LFC=-2.9) and phenylalanine ammonia-lyase1 (LFC=-2.9), were down regulated in 5057, while in ZD05, secondary metabolism and defence genes, bx13 (LFC=1.8), chalcone synthase (LFC=1.8), phenylalanine ammonia-lyase (LFC=2.6) and antiapoptotic gene, bax inhibitor1 (LFC=1.8) were upregulated. Striga hermonthica populations in Kenya and Nigeria are genetically distinct and ecotypes exist within Nigeria. Genes involved in secondary metabolism and defence were upregulated in the resistant maize genotype, but down regulated in the susceptible genotype. The resistant line mobilized a more comprehensive response to the parasite than the susceptible line

Genetic diversity of tropical maize inbred lines combining resistance to Striga hermonthica with drought tolerance using SNP markers

Striga hermonthica and drought are the major stresses limiting maize yields in sub-Saharan Africa. The search for diverse maize lines’ tolerance to drought and resistance to S. hermonthica (DTSTHR) is very crucial for yield improvement in areas affected by the two stresses. Understanding the genetic diversity among the lines is important to develop cultivars resistant to S. hermonthica and tolerant to drought. The lines were developed from biparental crosses of drought-tolerant and Striga-resistant lines. A total of 128 DTSTHR maize lines were characterized using single-nucleotide polymorphism (SNP) markers. Results of the cluster analysis based on 3297 SNP markers showed four distinct groups consistent with the pedigrees of the lines. Furthermore, model-based analysis also formed the same groups of the DTSTHR lines. Integrating the pedigree information with combining ability and the SNP analyses may provide defined heterotic groups for maize improvement work in West and Central Africa. These results also help breeders to utilize DTSTHR lines present at IITA for developing biparental crosses without disrupting the heterotic groups they have established in their breeding programmes

Classification of elite cassava varieties (Manihot esculenta Crantz) cultivated in Benin Republic using farmers’ knowledge, morphological traits and simple sequence repeat (SSR) markers

Published online: 23 August 2017Cassava (Manihot esculenta Crantz) is an important food security crop or resource for poor rural communities particularly in Africa. The crop’s ability to produce high yields even under poor conditions and storability of its roots underground for longer periods or until needed makes it a model ‘food security crop’. In Benin Republic, cassava has been recognized as one of the major crop contributing towards dynamic value chains generating incomes for small-holder farmers. The crop is grown all over the country, however, the increased production are mainly recorded from far south and central parts of the country. Genetic improvement of cassava in Benin Republic is limited because of poor knowledge of genetic diversity present within the country. The main objective of this study was to assess the genetic diversity and relationships among elite cassava varieties collected from different regions of Benin using fluorescently labelled simple sequence repeat (SSR) markers and to compare the results with farmer’s knowledge and morphological traits. A total of 96 cultivars collected from major cassava growing areas such as Southern and Central Benin were classified into 24 different groups using farmers’ knowledge, while classification based on 18 morphological traits resulted in five groups. In total, sixteen SSR markers were tested for molecular analysis of the ninety-six cassava varieties. Among the sixteen, twelve SSR markers gave good banding pattern and were used to genotype the varieties. An average of 3.58 and 0.47 for number of alleles and polymorphism information content respectively was observed. The observed heterozygosity (Ho) ranged from 0.23 to 1.0 with an average of 0.66 indicating moderate level of diversity among the cultivars. Based on the proportion of shared alleles and hierarchical clustering, the 96 elite cassava varieties were classified as 74 unique varieties. Principal component analysis and analysis of molecular variance revealed no significant variation between the regions thus, explaining regular exchange of planting materials among cassava farmers across various regions. The moderate level of genetic diversity in famer’s field, revealed in the present study, is a good indication of the need for broadening the genetic base of cassava in Benin Republic and establishing a formal breeding program in the country

Transcriptomics of host-specific interactions in natural populations of the parasitic plant purple witchweed (Striga hermonthica)

Published online: 30 Jul 2019Host-specific interactions can maintain genetic and phenotypic diversity in parasites that attack multiple host species. Host diversity, in turn, may promote parasite diversity by selection for genetic divergence or plastic responses to host type. The parasitic weed purple witchweed [Striga hermonthica (Delile) Benth.] causes devastating crop losses in sub-Saharan Africa and is capable of infesting a wide range of grass hosts. Despite some evidence for host adaptation and host-by-Striga genotype interactions, little is known about intraspecific Striga genomic diversity. Here we present a study of transcriptomic diversity in populations of S. hermonthica growing on different hosts (maize [Zea mays L.] vs. grain sorghum [Sorghum bicolor (L.) Moench]). We examined gene expression variation and differences in allelic frequency in expressed genes of aboveground tissues from populations in western Nigeria parasitizing each host. Despite low levels of host-based genome-wide differentiation, we identified a set of parasite transcripts specifically associated with each host. Parasite genes in several different functional categories implicated as important in host–parasite interactions differed in expression level and allele on different hosts, including genes involved in nutrient transport, defense and pathogenesis, and plant hormone response. Overall, we provide a set of candidate transcripts that demonstrate host-specific interactions in vegetative tissues of the emerged parasite S. hermonthica. Our study shows how signals of host-specific processes can be detected aboveground, expanding the focus of host–parasite interactions beyond the haustorial connection

Association analysis for resistance to Striga hermonthica in diverse tropical maize inbred lines

Open Access Journal; Published online: 17 Dec 2021Striga hermonthica is a widespread, destructive parasitic plant that causes substantial yield loss to maize productivity in sub-Saharan Africa. Under severe Striga infestation, yield losses can range from 60 to 100% resulting in abandonment of farmers’ lands. Diverse methods have been proposed for Striga management; however, host plant resistance is considered the most effective and affordable to small-scale famers. Thus, conducting a genome-wide association study to identify quantitative trait nucleotides controlling S. hermonthica resistance and mining of relevant candidate genes will expedite the improvement of Striga resistance breeding through marker-assisted breeding. For this study, 150 diverse maize inbred lines were evaluated under Striga infested and non-infested conditions for two years and genotyped using the genotyping-by-sequencing platform. Heritability estimates of Striga damage ratings, emerged Striga plants and grain yield, hereafter referred to as Striga resistance-related traits, were high under Striga infested condition. The mixed linear model (MLM) identifed thirty SNPs associated with the three Striga resistance-related traits based on the multi-locus approaches (mrMLM, FASTmrMLM, FASTmrEMMA and pLARmEB). These SNPs explained up to 14% of the total phenotypic variation. Under non-infested condition, four SNPs were associated with grain yield, and these SNPs explained up to 17% of the total phenotypic variation. Gene annotation of significant SNPs identified candidate genes (Leucine-rich repeats, putative disease resistance protein and VQ proteins) with functions related to plant growth, development, and defense mechanisms. The marker-effect prediction was able to identify alleles responsible for predicting high yield and low Striga damage rating in the breeding panel. This study provides valuable insight for marker validation and deployment for Striga resistance breeding in maize