Genetic variation, Heritability estimates and GXE effects on yield traits of Mesoamerican common bean (Phaseolus vulgaris L) germplasm in Uganda (original) (raw)
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African Journal of Biotechnology, 2014
The knowledge and understanding of the genetic variability of common bean (Phaseolus vulgaris L.) germplasm is important for the implementation of measures addressed to their utilizations and conservation. The objective of this study was to characterize common bean in Uganda using polymorphic molecular markers for use in hybridization and variety development. Genomic DNA was extracted from plants at the first trifoliate leaf stage growing in pots using the modified cetyltrimethylammonium bromide (CTAB) method. The gene pool membership (Andean vs. Mesoamerican) for each accession was established with the phaseolin marker. Simple sequence repeat (SSR) alleles were separated by capillary electrophoresis that provided further information on the organization of genetic diversity. The Andean and Mesoamerican genotypes were present in similar frequencies (51 vs. 49%, respectively). All SSR markers tested were polymorphic with mean polymorphism information content (PIC) of 0.8. The model-based cluster analysis of SSR diversity in the STRUCTURE software found three sub populations (K3.1, K3.2 and K3.3) genetically differentiated with moderate Wrights fixation indices (F ST) values 0.14, 0.12 and 0.09, respectively and many cases of admixture. The STRUCTURE result was confirmed by principal coordinate analysis (PCoA) which also clustered beans in three groups. Most Andean genotypes were included in K3.1 and Mesoamerican genotypes belonged to the K3.2 and K3.3 subgroups. This study sets the stage for further analyses for agronomic traits such as yield, resistance to biotic and abiotic stresses and the need for germplasm conservation.
African Journal of Biotechnology, 2018
This experiment was conducted to evaluate 36 common bean genotypes including seven released varieties to generate information on the extent of genetic variability, heritability and expected genetic advance of yield and yield related traits. The field experiment was conducted in 2015 at two locations (Abaya and Yabello) and genotypes were planted in triple lattice design. Data were collected on yield and important agronomic traits. The estimated genotypic (GCV) and phenotypic (PCV) coefficient of variations ranged from 4.82 to 9.85% and 7.03 to 12.93%, respectively for combined analyses. The PCV values were relatively greater than GCV in magnitude for all traits, of which the magnitude of the differences were large for grain yield, seeds number per plant and number of primary branches, but was relatively low for plant height and number of seeds per pod. Broad sense heritability ranged from 18.29 to 58.6%, and genetic advance as percentage of mean ranged from 4.25 to 14.42%. Only plant height and seed number per pod had moderate heritability coupled with relatively high genetic advance values.
African Journal of Agricultural Research, 2019
Knowledge of the sources and magnitude of variability among genotypes plays a pivotal role in any crop improvement program to maximize gains from selection. This experiment was conducted at Bako Agricultural Research Center in 2011 cropping season with the objective of studying and estimating the extent of genetic variability in common bean genotypes under sole and mixed cropping systems. Meanwhile, the wider range of variability observed from the mean of various quantitative traits. The genotypes that varied by cropping system depicted the presence of high level of variability. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) values were recorded for hundred grain weight (29.56 and 35.46 g), biological yield (27.22 and 31.37) and grain yield (26.60 and 31.54 q/ha), whereas the lowest GCV and PCV values were recorded for days to maturity of sole common bean genotypes. Phenotypic variance in both sole and mixed cropping systems was higher than that of genotypic variances. This implies that, considerable contribution of environmental factors to the phenotypic expression of the genotypes. High broad sense heritability as observed under both sole and intercropping systems indicated that, genetic improvement can be obtained through further selection programme. Important agronomic traits: pods per plant, seeds per pod and branches per plant had positive and significant correlation with grain yield in most cases. Path coefficient analysis at genotypic level indicated that all traits except plant height, seeds per pod and hundred grain weights exerted their positive direct effect on grain yield. Hence, the current study identified the presence of wide variability between those common bean genotypes which can be used for further breeding program and selection can be made using those traits associated to yield.
Theoretical and Applied Genetics, 2009
The East African highlands are a region of important common bean production and high varietal diversity for the crop. The objective of this study was to uncover the diversity and population structure of 192 landraces from Ethiopia and Kenya together with four genepool control genotypes using morphological phenotyping and microsatellite marker genotyping. The germplasm represented different common bean production ecologies and seed types common in these countries. The landraces showed considerable diversity that corresponded well to the two recognized genepools (Andean and Mesoamerican) with little introgression between these groups. Mesoamerican genotypes were predominant in Ethiopia while Andean genotypes were predominant in Kenya. Within each country, landraces from different collection sites were clustered together indicating potential gene flow between regions within Kenya or within Ethiopia. Across countries, landraces from the same country of origin tended to cluster together indicating distinct germplasm at the national level and limited gene flow between the two countries highlighting divided social networks within the regions and a weak trans-national bean seed exchange especially for landrace varieties. One exception to this may be the case of small red-seeded beans where informal cross-border grain trade occurs. We also observed that genetic divergence was slightly higher for the Ethiopian landraces compared to Kenyan landraces and that Mesoamerican genotypes were more diverse than the Andean genotypes. Common beans in eastern Africa are often cultivated in marginal, risk-prone farming systems and the observed landrace diversity should provide valuable alleles for adaptation to stressful environments in future breeding programs in the region.
Advances in Agriculture
This study was conducted on one hundred common bean landraces at the Jimma Agricultural Research Center, Melko, with the objective of assessing genetic variability and association of traits in common bean landraces collected from different parts of Ethiopia. The experiment was laid out in a simple lattice design with two replications. Analysis of variance showed significant differences among genotypes for all traits. This highly significant difference indicates the existence of large variability among genotypes. High phenotypic coefficients of variation and genotypic coefficients of variation were obtained for plant height (19.43, 11.73), pod length (11.27, 10.69), and 100-seed weight (15.42, 12.74). High heritability in the broad sense was found for days to 50% flowering (66.98), days to 90% maturity (87.43), pod length (90.03), pod width (78.23), harvest index (98.67), and 100-seed weight (68.31). High genetic advance as a percentage of mean with high heritability was obtained for...
Journal of Plant breeding and Crop Science, 2019
The present study was conducted to estimate the genetic variability, heritability, genetic advance and association among selected agronomic traits of common bean landraces from South western Kenya. The field experiment was conducted using 52 common bean landraces at the Kenya Agricultural and Livestock Research Organization (KALRO), Kisii Research Center during 2015 and 2016 main cropping seasons. The experimental design was randomized complete block (RCBD) with three replications. Analysis of variance revealed significant differences indicating the existence of genetic variability among the 52 landraces for 14 quantitative traits studied. The genotypic coefficient of variation ranged from 1.00% for biological yield to 84.69% for pod width, while the phenotypic coefficient of variation ranged from 2.34% for biological yield to 84.40% for number of branches. The estimated broad sense heritability ranged from 60.20% for seeds per plant to 87.57% for days to emergence. Estimates of genetic advance as percent of mean ranged from 10.15% for biological yield to 97.45% for number of branches. Positive and highly significant association of plant height, days from planting to 50% flowering, number of pods per plant and biological yield was observed with seed yield per plant, hence these traits may be directly attributed for the improvement of seed yield. High hereditability and genetic advance was obtained for plant height, 100 seed weight, pod width and number of branches, indicating additive gene effects in controlling the traits and these traits could be used as suitable criteria for selection and improvement of common bean in breeding programs.
Open Agriculture , 2024
The performance of most crop genotypes varies significantly depending on their genotype–environment interactions. Providing information on high-yielding and well-adapted common bean genotypes in a given environment is crucial for small-holder farmers to boost their productivity. A field trial was conducted at the Gendo and Wara locations over two consecutive seasons to understand genotype–environment interactions on grain yield and to identify and select common bean genotypes that were better adapted and had high yield potential for production. Ten genotypes were evaluated for their performance using a randomized complete block design with three replications. The AMMI and GGE models were used to identify superior genotypes regarding their mean grain yield performance. The AMMI analysis of variance results showed that grain yield was significantly (p ≤ 0.05) influenced by genotype–environment interactions. This shows that genotypes varied in grain yield mean performance across environments, indicating the possibility of selecting suitable genotypes with specific and broad adaptability. The sum of squares factor indicated that grain yield variation was contributed by the genotype (61.0%), followed by the environment (29.80%) and the genotype–environment interaction effect (9.20%) of the total variation. The AMMI and GGE biplot analysis results showed that SER-119 and SER-125 were identified as the best genotypes regarding their mean grain yield performance. Additionally, the genotype selection index analysis result indicated that SER-119 and SER-125 were stable and consistently exhibited high mean performance in all evaluated settings. Therefore, SER-119 and SER-125 are prime candidates for production in various agroecologies suitable for common bean cultivation in Dawuro zones. The use of tools like GGE biplots and AMMI analysis helped visualize the genotype–environment interactions, aiding in the selection of appropriate genotypes for both specific and wide adaptability.
TAG Theoretical and …, 2010
The Great Lakes region of Central Africa is a major producer of common beans in Africa. The region is known for high population density and small average farm size. The common bean represents the most important legume crop of the region, grown on over a third of the cultivated land area, and the per capita consumption is among the highest in the world for the food crop. The objective of this study was to evaluate the genetic diversity in a collection of 365 genotypes from the Great Lakes region of Central Africa, including a large group of landraces from Rwanda as well as varieties from primary centers of diversity and from neighboring countries of Central Africa, such as the Democratic Republic of Congo and Uganda, using 30 fluorescently labeled microsatellite markers and automated allele detection. In addition, the landraces were evaluated for their seed iron and zinc concentration to determine if genetic diversity influenced nutritional quality. Principal coordinate and neighbor-joining analyses allowed the separation of the landraces into 132 Andean and 195 Mesoamerican (or Middle American) genotypes with 32 landraces and 6 varieties intermediate between the gene pools and representing inter-gene pool introgression in terms of seed characteristics and alleles. Genetic diversity and the number of alleles were high for the collection, reflecting the preference for a wide range of seed types in the region and no strong commercial class preference, although red, red mottled and brown seeded beans were common. Observed heterozygosity was also high and may be explained by the common practice of maintaining seed and plant mixtures, a coping strategy practiced by Central African farmers to reduce the effects of abiotic and biotic stresses. Finally, nutritional quality differed between the gene pools with respect to seed iron and zinc concentration, while genotypes from the intermediate group were notably high in both minerals. In conclusion, this study has shown that Central African varieties of common bean are a source of wide genetic diversity with variable nutritional quality that can be used in crop improvement programs for the region.
Research & Reviews: Journal of Botany , 2021
This experiment was conducted in Guraghe and Siltie Zones of Southern Ethiopia to assess the extents of variability and associations of characters among common bean genotypes. Data were collected on nine quantitative traits. The analysis of variance revealed significant variation among the traits. Moderate genotypic and phenotypic coefficient of variation was observed for 100 seeds' weight, pod length and seed per plant. Highest heritability and genetic advances as percent mean values were observed for 100 seeds' weight and pod length. Seed yield had positive and significant association with most traits at both phenotypic and genotypic levels. The maximum positive direct effects on seed yield were exerted by pods per plant and days to 90% maturity. The moderate positive indirect effect on seed yield was exerted days to 90% maturity through pods per plant. Four major PCs explained 79.72% of total variation. Pod per plant from all PCs, seed yield and days to 90% maturity were from PC1, seed per pod and days to 50% flowering from PC1 and PC2, plant height from PC2 and PC3 and seed per plant from PC1, PC3. Therefore, in future these traits would be used for selection of genotypes as improving seed yield among these common bean genotypes.
Advances in agriculture, 2023
Twenty-fve common bean genotypes were evaluated to assess the genetic variability, trait association, and determine the direct and indirect efects of traits on seed yield. Te genotypes were grown in a lattice design at the research farm of the Melkassa Agricultural Research Center, Melkassa and Miesso, in the 2018 cropping season. Analysis of variance revealed that signifcant diferences were observed among the genotypes at individual locations. Te phenotypic coefcient of variation values were moderate for number of nodes, seeds per pod, plant height, and hundred seed weight at Melkassa. Moderate genotypic coefcient of variation values were obtained for pods per plant and seeds per pod. At Miesso, moderate phenotypic coefcients of variation values were recorded for number of nodes, hundred seed weight, and plant height. High heritability estimates were obtained for seed yield and hundred seed weight at Melkassa and for seed yield at Miesso, indicating that selection could be fairly easy and improvement is possible using these traits in a common bean breeding program. High genetic advances were obtained for seed yield and pods per plant at Melkassa, while moderate genetic advances as a percent of the mean were attained for plant height, hundred seed weight, and seeds per pod. Similarly, at Miesso, high and moderate genetic advances as percent of mean values were obtained for seed yield and hundred seed weight, respectively. Seed yield showed positive and signifcant phenotypic association with days to fowering, internode length, and pods per plant at Melkassa and had positive and signifcant phenotypic association with seeds per pod and hundred seed weight at Miesso. Hence, selection of those genotypes based on the traits with high genotypic coefcient of variability, heritability, genetic advance, and positive correlation coefcient and direct efect on seed yield can be recommended for further yield improvement at the respective location and at the national level in general.