Browsing by Author "Dzidzienyo, D.K."
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Item Allelic diversity of S-RNase alleles in diploid potato species(Theoretical and Applied Genetics, 2016-10) Dzidzienyo, D.K.; Bryan, G.J.; Wilde, G.; Robbins, T.P.Key message: The S-ribonuclease sequences of 16 S-alleles derived from diploid types of Solanum are presented. A phylogenetic analysis and partial phenotypic analysis support the conclusion that these are functional S-alleles. Abstract: S-Ribonucleases (S-RNases) control the pistil specificity of the self-incompatibility (SI) response in the genus Solanum and several other members of the Solanaceae. The nucleotide sequences of S-RNases corresponding to a large number of S-alleles or S-haplotypes have been characterised. However, surprisingly, few S-RNase sequences are available for potato species. The identification of new S-alleles in diploid potato species is desirable as these stocks are important sources of traits such as biotic and abiotic resistance. S-RNase sequences are reported here from three distinct diploid types of potato: cultivated Solanum tuberosum Group Phureja, S. tuberosum Group Stenotomum, and the wild species Solanum okadae. Partial S-RNase sequences were obtained from pistil RNA by RT-PCR or 3′RACE (Rapid Amplification of cDNA Ends) using a degenerate primer. Full-length sequences were obtained for two alleles by 5′RACE. Database searches with these sequences identified 16 S-RNases in total, all of which are novel. The sequence analysis revealed all the expected features of functional S-RNases. Phylogenetic analysis with selected published S-RNase and S-like-RNase sequences from the Solanaceae revealed extensive trans-generic evolution of the S-RNases and a clear distinction from S-like-RNases. Pollination tests were used to confirm the self-incompatibility status and cross-compatibility relationships of the S. okadae accessions. All the S. okadae accessions were found to be self-incompatible as expected with crosses amongst them exhibiting both cross-compatibility and semi-compatibility consistent with the S-genotypes determined from the S-RNase sequence data. The progeny analysis of four semi-compatible crosses examined by allele-specific PCR provided further confirmation that these are functional S-RNases. © 2016, The Author(s).Item Assessment of four plant extracts as maize seed protectants against Sitophilus zeamais and Prostephanus truncatus in Ghana(Taylor & Francis Group, 2021) Gariba, S.Y.; Dzidzienyo, D.K.; Eziah, V.Y.Sitophilus zeamais and Prostephanus truncatus can cause weight loss of about 20 to 90% of untreated stored maize seeds. This study assesses four plants (Lantana camara, Moringa oleifera, Citrus sinensis and Hyptis suaveolens) extracts as seed maize protectants against the two insects in Ghana. The study was laid out in a CRD with three replications. Dried powders (5 and 10% w/w) and aqueous extracts (0.05 and 0.1 g/mL) of the botanicals were evaluated for their insecticidal activity with untreated control and Actellic included as checks. Oviposition and survivorship of insects decreased in grains treated with plant extracts. The phytochemical analysis revealed that compounds such as alkaloids, saponins, tannins and pheno lic, steroids, flavonoids, anthraquinones, phlobatannins, cardiac glycosides and ter penoids were recorded in all four plant extracts. These compounds may have caused lower progeny emergence, inhibitory effect, repellent action and antifeedant effect to S. zeamais and P. truncatus in grains treated with the botanicals. Maize seeds treated with botanicals after 10 weeks in cribs recorded a reduction in the percentage of seeds damaged and weight loss caused by the two insects compared to the untreated seeds. The study proposes that the botanicals tested, especially H. suaveolens have the potential to enhance quality seed production thereby boosting growth in the seed industry. The botanicals are recommended for use by seed producers and farmers to control P. truncatus and S. zeamais in stored maize seeds.Item Genetic Diversification and Selection Strategies for Improving Sorghum Grain Yield Under Phosphorous-Deficient Conditions in West Africa(agronomy, 2019-11-11) Dzidzienyo, D.K.; Diallo, C.; Rattunde, H.F.W.; Gracen, V.; Touré, A.; Nebié, B.; Leiser, W.; Sissoko, I.; Danquah, E.Y.; Diallo, A.G.; Sidibé, B.; Sidibé, M.; Weltzien, E.Sorghum, a major crop for income generation and food security in West and Central Africa, is predominantly grown in low-input farming systems with serious soil phosphorus (P) deficiencies. This study (a) estimates genetic parameters needed to design selection protocols that optimize genetic gains for yield under low-phosphorus conditions and (b) examines the utility of introgressed backcross nested association mapping (BCNAM) populations for diversifying Malian breeding materials. A total of 1083 BC1F5 progenies derived from an elite hybrid restorer “Lata-3” and 13 diverse donor accessions were evaluated for yield and agronomic traits under contrasting soil P conditions in Mali in 2013. A subset of 298 progenies were further tested under low-P (LP) and high-P (HP) conditions in 2014 and 2015. Significant genetic variation for grain yield was observed under LP and HP conditions. Selection for grain yield under LP conditions was feasible and more e cient than the indirect selection under HP in all three years of testing. Several of the BCNAM populations exhibited yields under LP conditions that were superior to the elite restorer line used as a recurrent parent. The BCNAM approach appears promising for diversifying the male parent pool with introgression of diverse materials using both adapted Malian breed and unadapted landrace material from distant geographic origins as donors.Item Groundnut production constraints and farmers’ trait preferences: a pre-breeding study in Togo(Journal of Ethnobiology and Ethnomedicine, 2018-11) Banla, E.M.; Dzidzienyo, D.K.; Beatrice, I.E.; Offei, S.K.; Tongoona, P.; Desmae, H.Background Groundnut is an important legume crop in Togo. However, groundnut yield has been steadily decreasing for decades as a result of lack of organized breeding program to address production constraints. Though, low yielding varieties and late leaf spot have been often reported as the most important constraints, there is no documented evidence. Identifying and documenting the major production constraints is a prerequisite for establishing a good breeding program with clearly defined priority objectives and breeding strategies. Thus, the objectives of this study were to identify groundnut production constraints and assess farmers’ preferred traits. Methods A participatory rural appraisal approach was used to collect data on agronomic practices, farmers’ preferences, and possible threats to production through individual and group interviews. Three regions and three villages per region were selected based on the representativeness of groundnut production systems. In each village, 20 farmers were randomly selected and interviewed; thus, a total of 180 farmers were interviewed. Content analysis was carried out for qualitative data and for quantitative data generated within and across regions, comparative descriptive statistics were carried out. Differences in perception and preferences were assessed using chi-square tests. Results The study has revealed that, though there were some variation across the regions, traits pertaining to yield such as pod yield (66.66%) and pod size (12.12%) were the most important. Leaf spot diseases, rosette and peanut bud necrosis (37.77%) and insects such as pod sucking bug and bruchid (27.77%) were considered to be the most important constraints limiting groundnut production. Among diseases, farmers in all the three regions indicated that late leaf spot is of economic importance which they associated to various causes such as maturity, drought, or insects. No gender differences were observed for the perception of constraints and groundnut traits preferences. Land size is significantly influenced by age and gender. Besides, farmers have pointed the lack of improved varieties and the unavailability of groundnut seeds highlighting the necessity of a sustainable groundnut seed system linked with a strong breeding program. Conclusion This study has enabled understanding of the farming practices, constraints, and farmers preferred characteristics, thus providing the basis for a participatory breeding program in Togo which should consider that farmers perceive low yielding varieties and diseases as major constraints to production.Item High Soil Phosphorus Application Significantly Increased Grain Yield, Phosphorus Content but Not Zinc Content of Cowpea Grains(MDPI, 2021) Mohammed, S.B.; Dzidzienyo, D.K.; Yahaya, A.; Umar, M.L.; Ishiyaku, M.F.; Tongoona, P.B.; Gracen, V.To ameliorate the impact of soil phosphorus (P) deficiency on cowpea, the use of P-based fertilizers is recommended. Plant zinc (Zn) is an essential nutrient required by plants in a wide range of processes, such as growth hormone production and metabolism. However, a negative association between plant Zn content and high P application has been reported in some crops. There are few reports about soil P application and plant Zn content relationship on cowpea. Thus, this study investigated the response of cowpeas to three P rates in the screenhouse (0, 1.5, and 30 mg P/kg) and field (0, 10, and 60 kg P2O5/ha) and their effects on plant P and Zn content, biomass, and grain yield. In the screenhouse, shoot and root dry weights, and shoot P and Zn content were measured. Shoot dry weight, grain yield, grain P, and Zn contents were determined from field plants. Higher rates of P led to increased shoot biomass and grain yield of the field experiment but were not associated with a significant change in shoot or grain Zn content. There was not a significant correlation between grain yield and Zn content in high soil P (p < 0.05). The effect of higher P application on reduced plant Zn contents may be genotype-dependent and could be circumvented if genotypes with high Zn content under high soil P are identified.Item Identifying key contributing root system traits to genetic diversity in field-grown cowpea (Vigna unguiculata L. Walp.) genotypes(Field Crops Research, 2019-02) Adu, M.O.; Asare, P.A.; Yawson, D.O.; Dzidzienyo, D.K.; Nyadanu, D.; Asare-Bediako, E.; Afutu, E.; Tachie-Menson, J.W.; Amoah, M.N.Cowpea is a grain legume that is grown extensively as an alternate protein and income source for many smallholder farmers. Characterising cowpea root phenotypes could provide the basis for developing genotypes with root system architecture (RSA) traits that increase soil resource acquisition. Measuring RSA traits of any field crop is a demanding task, in terms of expediency, time, cost, and competence. Targeted root phenotyping strategies focusing on a few relevant traits might aid in side-stepping some of the challenges associated with phenotyping roots of field crops. The objectives of this study were to (i) measure genotypic variation for RSA and shoot traits of cowpea genotypes; and (ii) identify candidate variables and genotypes that contribute the largest share of variance. Sixty cowpea accession were grown in field trials at the University of Cape Coast, Ghana. Seventy variables, mostly quantitative RSA traits were measured. Multivariate analysis was used to determine major traits contributing to variation. There were significant differences (P < 0.05) for the majority of traits evaluated. Fifty-nine traits had coefficients of variation of ≥0.3 among genotypes and were selected for further examination. Broad-sense heritability (H2) estimates were generally intermediate to high and ranged from 0.11 to 0.96. The Shannon-Weaver diversity index (H’) was variable among traits and ranged from 0.00 to 0.88. Shoot and root biomass correlated closely and positively with count- and length- and diameter-related traits. Cluster analysis identified three homogeneous genotype groups and identified groups of cowpea genotypes that could be exploited in breeding programs to improve the genetic basis of root traits. The first nine principal components explained over 74% of total genotypic variation for the twenty-nine traits included in the PCA. Sixteen traits contributed more than other traits to the variability in PC1 and PC2. Soil and root tissue angle-related traits, shoot and root diameter-related traits, root biomass, hypocotyl root length, root count and lateral root density -related traits were among the top 50% of the most important traits contributing to variation and thus warrant consideration in efforts to breed for improved genotypes in cowpea. The workflow presented offers a robust, cost-effective and simple approach to identifying focal root traits that contribute to diversity in grain legumes. The results could potentially facilitate the characterization of specific traits suitable for targeted genotype selection and breeding of new cowpea varieties for efficient RSAs.Item Learning from farmers to improve sorghum breeding objectives and adoption in Mali(Journal of Crop Improvement, 2018-11) Diallo, C.; Isaacs, K.; Gracen, V.; Touré, A.; Weltzien Rattunde, E.; Danquah, E.Y.; Sidibé, M.; Dzidzienyo, D.K.; Rattunde, F.; Nébié, B.; Sylla, A.; Tongoona, P.B.Many efforts have been made to improve sorghum [Sorghum bicolor (L.) Moench] varieties, but adoption of improved varieties remains low. Sorghum has diverse panicle architecture and grain qualities that vary within and between races, and utilization and adoption may depend on these traits. Recent efforts in West Africa to improve local guinea race germplasm as a base material have diversified potential options: there are breeding materials with a range of panicle types with increased grain number per panicle and a range of droopiness, as well as laxness and threshability. This study was designed to expand our understanding about sorghum grain and panicle traits that are important for farmers in the Sudan savanna zone of Mali. We combined a sorghum panicle sorting activity with qualitative interviews in Mande and Dioïla to understand farmers’ knowledge and preferences about sorghum characteristics. A total of 20 panicle sorting activities and 20 interviews were conducted with men and women sorghum producers. Based on their roles and responsibilities in sorghum production and processing, farmers associated specific panicle types, plant types, and grain traits with aspects of pest control, threshability, storage duration, and yield. Farmers preferred open panicles and droopy architecture for disease and pest control; hard grains for storage and appropriate ratios of flour and grits; high density of grain on the panicle for yield; and specific glume qualities for threshability. Breeding programs need to consider these regional preferences and gender roles to develop appropriate material and increase adoption of productive varieties.Item Multienvironment Evaluation of Tannin-Free Photoperiod-Insensitive Sorghum (Sorghum bicolor (L) Moench) for Yield and Resistance to Grain Mold in Senegal(Hindawi, 2021) Diatta, C.; Sarr, M.P.; Tovignan, T.K.; Aidara, O.; Dzidzienyo, D.K.; Diatta-Holgate, E.; Faye, J.M.; Danquah, E.Y.; Offei, S.K.; Cisse, N.Combining resistance to grain mold with high grain yield in tannin-free white-grained photoperiod-insensitive sorghum is of major interest for farmers in Senegal. In this study, GGE biplot analysis was used to assess the performance, adaptability, and stability of eleven sorghum parental lines and their hybrid combinations for yield and grain mold resistance under Senegalese environments. Eleven inbred lines along with their 22 hybrid combinations and one check were evaluated across three sites during the 2015 and 2016 rainy seasons under natural grain mold infestation. (e results of this study showed strong genetic variability among studied genotypes for all measured traits. (e highly significant G× E interaction effects for grain yield and panicle grain mold rating score (PGMR) indicated that both traits are influenced by genetics and to some extent by environment. Broad-sense heritability computed was high for all these traits except PGMR, showing a high environmental pressure on this later. (e study showed that grain mold pressure in the studied sites decreased following a South-North gradient similar to the rainfall pattern, with the south region wetter, explaining the high disease pressure in Darou and Sinthiou Maleme contrary to Bambey. (e GGE biplot analysis performed showed that the first two principal components explained 85.84% of the total variation of GGE sum of squares for grain yield. (e which won-where view of the GGE biplot for grain yield showed that the hybrid HB16 was the most adapted for Bambey area. (e ranking of genotypes based on both yield performance and stability showed that HB16, HB5, HB21, HB18, and HB7 were the best hybrids combining high grain yield, high stability performance, and tolerance to grain mold disease across the test environments. (These hybrids outperformed the best yielding inbred line P29 (2196.7 kg ha−1 ) with grain yield advantages ranging 17–60%. (erefore, these hybrids could be recommended to farmers in order to improve sorghum yield in Senegal.Item Retailers’ knowledge and practices on the storage and handling of certified vegetable seeds: A case study of the Ashanti Region, Ghana(Sustainable Futures, 2021) Adom, J.A.; Dzidzienyo, D.K.; Ofosu-Anim, J.Poor seed storage and handling practices adversely affect seed quality. To investigate retailers’ knowledge and practices in handling and storing certified vegetable seeds to ensure seed quality maintenance, a survey was conducted with a questionnaire and a thermo-hygrometer in the Ashanti Region. Results indicated retailers were aware of the factors that affected seed quality during storage. Retailers stored seeds at room temperature, and repackaged seeds in smaller sizes due to challenges like lack of cold storage, lack of credits, seed pricing and seed package sizes. Retailers require cold storage facilities to ensure continuous supply of quality seeds to farmers.Item Scalable Sparse Testing Genomic Selection Strategy for Early Yield Testing Stage(Frontiers, 2021) Atanda, S.A.; Olsen, M.; Crossa, J.; Burgueño, J.; Rincent, R.; Dzidzienyo, D.K.; Beyene, Y.; Gowda, M.; Dreher, K.; Boddupalli, P.; Tongoona, P.; Danquah, E.Y.; Olaoye, G.; Robbins, K.R.To enable a scalable sparse testing genomic selection (GS) strategy at preliminary yield trials in the CIMMYT maize breeding program, optimal approaches to incorporate genotype by environment interaction (GEI) in genomic prediction models are explored. Two cross-validation schemes were evaluated: CV1, predicting the genetic merit of new bi-parental populations that have been evaluated in some environments and not others, and CV2, predicting the genetic merit of half of a bi-parental population that has been phenotyped in some environments and not others using the coefficient of determination (CDmean) to determine optimized subsets of a full-sib family to be evaluated in each environment. We report similar prediction accuracies in CV1 and CV2, however, CV2 has an intuitive appeal in that all bi-parental populations have representation across environments, allowing efficient use of information across environments. It is also ideal for building robust historical data because all individuals of a full-sib family have phenotypic data, albeit in different environments. Results show that grouping of environments according to similar growing/management conditions improved prediction accuracy and reduced computational requirements, providing a scalable, parsimonious approach to multi-environmental trials and GS in early testing stages. We further demonstrate that complementing the full-sib calibration set with optimized historical data results in improved prediction accuracy for the cross-validation schemes