Browsing by Author "Adjebeng-Danquah, J."
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Item Agronomic performance and genotypic diversity for morphological traits among cassava genotypes in the Guinea Savannah Ecology of Ghana(Korean Society of Crop Science, 2016) Adjebeng-Danquah, J.; Gracen, V.E.; Offei, S.K.; Asante, I.K.; Manu-Aduening, J.We evaluated the agronomic performance and diversity for morphological traits among a collection of local and exotic cassava genotypes in the Guinea Savannah agroecology of Ghana. One hundred and fifty cassava genotypes were assessed using 28 agro-morphological (18 qualitative and 10 quantitative) traits recorded from three months after planting until harvesting at 12 months after planting. There was significant genetic variability among the genotypes for most of the traits evaluated. High broad sense heritability was observed for most of the traits. Principal component analyses of the traits indicated that the first three principal component axes which accounted for more than 55% of the variation for 10 quantitative traits included storage root yield, number of leaves, harvest index, height at first branching, and plant height as the most important traits. A greater proportion of the phenotypic variances of plant height, height at branching, and harvest index were accounted for by genetic variances indicating that progress could made with selection. Pearson correlation analysis indicated that a number of traits were related to growth and yield of cassava in the Guinea Savanna ecology, making indirect selection for root yield possible. The study revealed ample genotypic variation in these morphological and agronomic traits to support selection for improved varieties. © Korean Society of Crop Science and Springer 2016.Item AMMI Stability Analysis and Estimation of Genetic Parameters for Growth and Yield Components in Cassava in the Forest and Guinea Savannah Ecologies of Ghana(Hindawi International Journal of Agronomy, 2017-07) Adjebeng-Danquah, J.; Manu-Aduening, J.; Gracen, V.E.; Kwadwo Asante, I.; Offei, S.K.yield stability using the additive main effect andmultiplicative interaction (AMMI) analysis.Highly significant (𝑃 < 0.001) effects of genotype, environment, and genotype ∗ environment interactionwere observed for all traits studied.TheAMMIanalysis of variance indicated that genotype accounted for 51% of the total sum of squares for height at first branching followed by environment (33%) and interaction (15%). For fresh root yield, environment effects accounted for 37% of the total sum of squares, whilst genotype and interaction accounted for 32% and 29%, respectively. Genotypic variances for harvest index (HI), plant height, storage root yield, and dry matter content contributed a greater proportion of the phenotypic variance indicating stronger genetic control. This suggests better chance of progress in the genetic improvement of these traits. Genotype MM96/1751 combined high yield with stability according to the yield stability index ranking across environments. On the other hand genotypes UCC 2001/449 and 96/1708 though high yielding were unstable according to AMMI stability value scores. However they can be tested further in more environments to ascertain their specific adaptability for release to farmers for cultivation to boost cassava production and ensure food security.Item AMMI Stability Analysis and Estimation of Genetic Parameters for Growth and Yield Components in Cassava in the Forest and Guinea Savannah Ecologies of Ghana(International Journal of Agronomy, 2017-07-13) Adjebeng-Danquah, J.; Manu-Aduening, J.; Gracen, V.E.; Asante, I.K.; Offei, S.K.Twenty cassava genotypeswere arranged in a randomised complete block design with three replications and assessed for growth and yield stability using the additive main effect andmultiplicative interaction (AMMI) analysis.Highly significant (𝑃 < 0.001) effects of genotype, environment, and genotype ∗ environment interactionwere observed for all traits studied.TheAMMIanalysis of variance indicated that genotype accounted for 51% of the total sum of squares for height at first branching followed by environment (33%) and interaction (15%). For fresh root yield, environment effects accounted for 37% of the total sum of squares, whilst genotype and interaction accounted for 32% and 29%, respectively. Genotypic variances for harvest index (HI), plant height, storage root yield, and dry matter content contributed a greater proportion of the phenotypic variance indicating stronger genetic control. This suggests better chance of progress in the genetic improvement of these traits. Genotype MM96/1751 combined high yield with stability according to the yield stability index ranking across environments. On the other hand genotypes UCC 2001/449 and 96/1708 though high yielding were unstable according to AMMI stability value scores. However they can be tested further in more environments to ascertain their specific adaptability for release to farmers for cultivation to boost cassava production and ensure food security.Item Genetic diversity and population structure analysis of Ghanaian and exotic cassava accessions using simple sequence repeat (SSR) markers(Heliyon, 2020-01-31) Asante, I.K.; Adjebeng-Danquah, J.; Manu-Aduening, J.; Agyare, R.Y.; Gracen, V.; Offei, S.K.Genetic diversity is fundamentally important in crop improvement and provides plants with the capacity to meet the demands of changing environments. This work was carried out to assess the diversity and the extent of genetic relatedness among a number of assembled cassava (Manihot esculenta Crantz) accessions. We conducted a microsatellite marker analysis of 89 cassava accessions collected from Ghanaian and exotic sources. These accessions were assayed using 35 simple sequence repeat (SSR) markers. A total of 167 alleles were detected from 35 polymorphic markers with an average of 4.77 alleles per locus. High allelic frequency was detected across the accessions, ranging from 0.32 to 0.99 with an average of 0.62 per marker. Observed heterozygosity ranged from 0.03 - 0.97 across the accessions. Polymorphism information content (PIC) ranged from 0.03 to 0.78 with a mean of 0.45, indicating high level of polymorphism across the accessions. Comparatively, higher number of alleles, gene diversity and observed heterozygosity were detected among the local accessions compared with the exotic accessions indicating rich genetic diversity among them. Population structure analysis based on STRUCTURE identified two subpopulations and a large number of admixtures. Cluster analysis based on the neighbour joining algorithim further separated the collection into seven sub-groupings irrespective of geographical origin. This indicates the possible sharing of common genomic regions occurring across the accessions. High allelic frequency differences and levels of heterozygosity were observed among the germplasm. These findings indicated significant genetic variability in the germplasm to warrant selection.Item Genetic Studies of Physiological and Morphological Traits Associated with Drought Tolerance in Cassava Genotypes(University of Ghana, 2014-12) Adjebeng-Danquah, J.; Gracen, V.; Offei, K. S.; Asante, K. I.; Manu-Aduening, J.This study was undertaken to identify key traits that are closely related to cassava yield under drought stress and also identify stable high yielding cassava genotypes under varying environments. A survey was conducted using in semi-structured questionnaire in three districts in the Northern Region involving 120 farmers to identify farmers’ perception on drought in cassava cultivation, production constraints, mitigation strategies and preferences for improved cassava genotypes. To identify ideal genotypes that meet farmers’ preferences, 150 cassava genotypes from local and exotic sources were assembled and assessed for diversity using morphological traits and simple sequence repeat markers. Subsequently 20 genotypes were selected and evaluated under irrigation and no irrigation to assess genetic variability in abscisic acid content, carbon isotope ratio, stomatal conductance, leaf temperature and root yield. Stability of genotypes for physiological and yield traits were also assessed using the additive main effect and multiplicative interaction (AMMI) and GGE biplot analyses. The survey indicated lack of credit as the most important constraint facing cassava cultivation in the region. Drought was the second most important constraint and the intensity was observed to be increasing. Majority of the farmers also preferred early maturing cassava varieties that are high yielding with good plant type and marketability. Factorial analysis of the morphological traits grouped the genotypes based on their origin with few exceptions. Principal component analysis further identified plant height, branching habit, distance between leaf scars, colour of end branches, root yield, harvest index and number of roots per plant as the traits contributing most of the variability in the groups. High level of heterozygosity was revealed by the simple sequence repeat markers which grouped the genotypes into seven distinct clusters irrespective of sources. Genetic variability was established for abscisic acid content which was higher under stress than irrigation. ABA content was negatively correlated with root yield, harvest index and above ground biomass yield meaning it can be used as indirect selection criteria against unproductive genotypes. Narrow genetic variation was observed for carbon isotope ratio which was higher under irrigation than no irrigation. Carbon isotope ratio was positively correlated with above ground biomass yield but not root yield. Stomatal conductance and leaf temperature were significantly different among genotypes and environments but genotype x environment interaction was not significant. Broad sense heritability estimates were high for most of the traits except stomatal conductance, above ground biomass yield, root number and stem diameter. AMMI analysis of plant height, severity of cassava mosaic disease, root yield, root length/girth ratio, above ground biomass yield and harvest index indicated stronger effect of environment than genotypes for all traits except CMD. The study established for the first time relationship between ABA content and cassava root yield on the field. Extension of roots to lower soil depts (L/G ratio) was also found to be detrimental to storage root yield. It was also found from this study that carbon isotope ratio influence above ground biomass and not storage root yield under stress conditions. Based on AMMI selections and the GGE biplot analysis, three genotypes, MM96/1751, UCC2001/449 and 00/0203 were identified as high yielding and stable across environments. These can be used as donor parents in improving local farmer-preferred varieties. Six genotypes (UCC2001/449, 96/1708, MM96/1751, 00/0203, 96/409 and I91934) had significantly higher root yield than the best local farmer preferred variety. These can be tested on-farm for official release to farmers for cultivation.Item Granular structure, physicochemical and rheological characteristics of starch from yellow cassava (Manihot esculenta) genotypes(International Journal of Food Properties, 2023) Akonor, P.T.; Tutu, C.O.; Arthur, W.; Adjebeng-Danquah, J.; Affrifah, N.S.; Budu, A.S.; Saalia, F.K.This study examined the structural and physicochemical characteristics of starch isolated from seven yellow cassava genotypes. The structural properties of yellow cassava starch from these cultivars were elucidated by scanning electron microscopy, X-ray diffractometry and Fourier Transformed Infrared Spectroscopy (FTIR). Their water interaction properties, digestibility and viscoelastic behavior were also compared, and principal component analysis was used to establish factors associated with the variability in properties of the starch. All the starches were of the A-type diffraction pattern, with crystallinity ranging between 31 and 37%. Most of the granules exhibited spherical and oval shapes, some with a flat surface on one side. They had smooth surfaces and their sizes ranged from 4 µm for round granules to 23 µm for the major axis of oval-shaped granules. Significant differences (p < .05) were observed in amylose content, in-vitro digestibility, peak and breakdown viscosity of the starches, and these ranged between 13.6–18.1%, 11.4–18.5%, 354–520 BU and 233–366 BU, respectively. Significant differences were also recorded in the hydration and textural behavior of starches from these cassava cultivars. The differences observed in granular and physicochemical properties are likely to influence the performance of these cassava cultivars in food applications.