1,720,992 research outputs found
Screening of Drought Tolerant Bread Wheat (Triticum aestivum L.) Genotypes using Yield Based Drought Tolerance Indices
No full textDrought is one of the major abiotic constraints seriously influencing bread wheat (Triticum aestivum L.) genotype production in Ethiopia. Genetic resources and selection methodologies are among the prerequisites to improve the efficiency of breeding for drought tolerance. The objectives of this study were to determine the principal selection indices for drought and to identify drought tolerant genotypes under drought conditions. 256 bread wheat genotypes were evaluated using a simple lattice design with two replications. Number of irrigation and the amount of water supply was similar for both water regimes until 50% heading stages. Non-stressed plots were irrigated 2 times after 50% heading stage, while stressed plots received no water in order to simulate terminal drought. Genotypes showed highly significant differences (P ≤ 0.01) for grain yield under non-stressed and stressed conditions. Principal component and correlation analyses revealed mean productivity, geometric mean productivity, grain yield index and stress tolerance index as the principal indices highly correlated with grain yield in the stressed and non-stressed environments, indicating their suitability for identifying superior genotypes. Genotypes 147 and 100 were identified as more tolerant, which could be useful for drought stress tolerance breeding. Cluster analysis classified the genotypes into nine clusters. Cluster IX consisted of four genotypes, 18,137,100 and 147 gave high grain yield under both the moisture -stressed and non-stressed conditions with high value of mean productivity, geometric mean productivity, grain yield index and stress tolerance index. Therefore, breeders can select suitable genotypes under water-stressed conditions and compare their performance under nonstressed conditions using MP, GMP, YI and STI indices as a means to combine information on performance under both conditions
AMMI and GGE biplot analysis for barley genotype yield performance and stability under multi environment condition in southern Ethiopia
No full textBarley (Hordeum vulgare L.) is a major grain crop farmed in Ethiopia throughout the long rainy season (Meher) and the short rainy season (Belg) of the year. Barley genotypes were subjected to multi-environment experiments in six different settings to identify stable genotypes and estimate the impact of genotype × environment interaction (GEI) on grain production. In each area, the field experiment was conducted from mid-July to January during the primary cropping season of 2021. Three replications of a randomized complete block design were used to set up the trials. According to the additive main effects and multiplicative interaction (AMMI) study, genotype (18.19%), GEI (22.98%), and environment (58.83%) all had an impact on the major treatment sum of squares. The more variance attributed to the environments is a sign of environmental diversity. Given that the two interaction principal component analysis (IPCAs) accounted for 76.94% of the interaction sum of squares, they were sufficient for cross-validation of the grain yield variance explained by GEI. In contrast to the GGE biplot approaches, which indicated genotypes G12, G3, and G9 as stable and high-yielding genotypes throughout the environments, the AMMI stability value identified genotypes G3, G12, and G9 as high yielding with stable performance across environments. In general, the GGE biplot and AMMI analysis models demonstrated that genotypes G12, G3, and G9 were stable and yielded well, making G3 acceptable for cultivation in a wider range of environments and G12 and G9 suitable for release
Correlation and path analysis of yield, yield contributing and malt quality traits of Ethiopian sorghum (Sorghum bicolor (L.) Moench) genotypes
No full textSorghum is a drought tolerant C4 tropical crop with wide diversity grown for food, feed and beverages. There is a growing demand for food and malt type sorghum varieties due to the low supply of mat barley, and climate resilient and gluten free nature of the crop. This study was initiated to estimate the associations among traits and the relative importance of traits in influencing grain yield and malting quality of sorghum genotypes. The experiment was conducted at Fachagama in Mhoni ARC, Northern Ethiopia in 2016/2017 using α- lattice design in two replications using supplementary irrigation. Data were collected on agronomic traits, and a selection of 300 g pure seeds were malted (18 hr steeping, 72 hr in 28°C germinated and 24 hr in 50°C dried) for malt quality analysis. Positive and significant correlations with grain yield of TKW (0.766, 0.715), KL (0.671, 0.644), KW (0.524, 0.491) HLW (0.532, 0.504, FHWE (0.257, 0.241) and DP (0.275, 0.271) at both phenotypic and genotypic level was found respectively. TKW exerted high positive genotypic (0.334) and phenotypic (0.287) direct effect and even higher indirect effect on grain yield, which indicated that attention should be given to TKW primarily for direct and indirect selection for yield improvement. Thousand kernel weight and fine grind hot water extract showed a significant positive correlation with diastatic power at genotypic level and increment in these traits results in advancement of diastatic power
Folksong based appraisal of bioecocultural heritage of sorghum (<it>Sorghum bicolor </it>(L.) Moench): A new approach in ethnobiology
No full textAbstract Background Sorghum is one of the main staple crops for the world's poorest and most food insecure people. As Ethiopia is the centre of origin and diversity for sorghum, the crop has been cultivated for thousands of years and hence the heritage of the crop is expected to be rich. Folksong based appraisal of bioecocultural heritage has not been done before. Methods In order to assess the bioecocultural heritage of sorghum by folksongs various research methods were employed. These included focus group discussions with 360 farmers, direct on-farm participatory monitoring and observation with 120 farmers, and key informant interviews with 60 farmers and development agents. Relevant secondary data was also collected from the museum curators and historians. Results The crop is intimately associated with the life of the farmers. The association of sorghum with the farmers from seed selection to utilization is presented using folksongs. These include both tune and textual (ballad stories or poems) types. Folksongs described how farmers maintain a number of varieties on-farm for many biological, socio-economic, ecological, ethnological and cultural reasons. Farmers describe sorghum as follows: Leaf number is less than twenty; Panicle hold a thousand seeds; a clever farmer takes hold of it. In addition, they described the various farmers' varieties ethnobotanically by songs. The relative importance of sorghum vis-à-vis others crops is similarly explained in folksong terms. Conclusion The qualitative description of farmers' characterisation of the crop systems based on folksongs is a new system of appraising farmers' bioecocultural heritage. Hence, researchers, in addition to formal and quantitative descriptions, should use the folksong system for enhanced characterisation and utilization of bioecocultural heritages. In general, the salient characteristics of the folksongs used in describing the bioecocultural heritages are their oral traditions, varied function, communal or individual recreation and message transmissions.</p
Infra-specific folk taxonomy in sorghum (<it>Sorghum bicolor </it>(L.) Moench) in Ethiopia: folk nomenclature, classification, and criteria
No full textAbstract Background Sorghum is one of the main staple food crops for the poorest and most food insecure people of the world. As Ethiopia is the centre of origin and diversity for sorghum, the crop has been cultivated for many thousands of years. Hence, indigenous knowledge based sorghum classification and naming has a long tradition. Methods In order to assess folk taxonomy, various research methods were employed, including, focus group interviews with 360 farmers, direct on-farm participatory monitoring with 120 farmers, key informant interviews with 60 farmers and development agents and semi-structured interviews with 250 farmers. In addition, diversity fairs were conducted with over 1200 farmers. Assessment of folk taxonomy consistency was assessed by 30 farmers' evaluation of 44 folk species. Results Farmers have been growing sorghum for at least 500 years (20 generations). Sorghum is named as Mishinga in the region. Farmers used twenty five morphological, sixty biotic and abiotic and twelve use-related traits in folk taxonomy of sorghum. Farmers classified their gene-pool by hierarchical classifications into parts that represented distinguishable groups of accessions. Folk taxonomy trees were generated in the highland, intermediate and lowland sorghum ecologies. Over 78 folk species have been identified. The folk species were named after morphological, use-related and breeding methodology used. Relative distribution of folk species over the region, folk taxonomy consistency, and comparison of folk and formal taxonomy are described. Conclusion New folk taxonomy descriptors have been identified and suggested to be used as formal taxonomy descriptors. It is concluded that integrated folk-formal taxonomy has to be used for enhanced collection, characterisation and utilization of on farm genetic resources.</p
Genetic variability of improved maize varieties (Zea mays L.) for acidic soil tolerance under contrasting environments in Assosa, Ethiopia
No full textMaize is the second most widely grown food cereal crop cultivated in the world and consumed in various form of as part of diets of human and animals. However, its production and productivity is affected by biotic and abiotic stresses among which, soil acidity is the key factor. This field experiment was conducted to estimate the genetic variability of maize for yield and yield related traits, and determine the association of traits with grain yield at Assosa and Bambasi districts during the 2017main cropping season. The experiment consisted of limed and unlimed soil as main plots and 21 maize varieties as the sub-plots arranged in a split plot design with 3 replications. Highly significant (P<0.01) differences were observed among maize varieties in yield and yield related-traits at both locations. Moderate to high genotypic coefficient variation, heritability and genetic advance as the percentage of mean values were observed for stalk biomass, ear biomass, diameter and length, and grain yield at both locations. Highly significant phenotypic and genotypic correlations were observed between thousand seed weight and number of kernels per row, thousand seed weight and ear diameter, and number of kernels per row. The yield was highly significant and positively associated with above stalk biomass, ear biomass, thousand seed weight, and number of kernels per row at both locations at the genotypic and phenotypic level. The phenotypic and genotypic correlation and path coefficient analysis of harvesting index, above ground biomass, ear biomass, number of ears harvested per plot, number of rows per ear, and ear length and these traits also showed a direct effect on yield. The highest yield in t/ha was obtained from variety BH547 (3.04) and (7.35) at Assosa and Bambasi, respectively. Additionally, higher yield was recorded from SPRH1, BH661 and BH546 varieties at both locations. Therefore, farmers could use the above varieties in the acidic soil until other advanced varieties are developed, but the exact significant impact and duration of lime management in the acidic soil for maize needs further investigations
Molecular diversity and population structure of the Ethiopian lentil (Lens culinaris Medikus) genotype assessment using SSR markers
No full textKnowledge of genetic diversity is essential for formulating effective germplasm collection, conservation
and utilization strategies in crop improvement programs. It also provides an opportunity to take corrective
steps infusing new genes to avoid risks associated with a narrow genetic base. Here, we analysed the
genetic diversity of 119 lentil genotypes, including 83 germplasm accessions from Ethiopia and 36 exotic
accessions from International Center for Agricultural Research in the Dry Areas, using 27 simple
sequence repeat (SSR) markers. Analysis Molecular of Variance estimated the variations of 82% within
and 18% among the populations. The degree of polymorphism observed among the populations was
100%. A total of 122 alleles were detected, which ranged from 2 to 7 alleles per locus, with a mean of
4.52 alleles per locus. The estimated gene diversity for 27 loci was 0.64. The average Shannon's
information index value of 1.19, showed the existence of high genetic variation within the genotypes.
The genetic similarity indices ranged from 0.21 to 1.00. The SSR markers showed an average
polymorphic information content (PIC) value of 0.58. Cluster analysis grouped the genotypes into five
major clusters as distinct genetic populations. This molecular diversity information provides a basis for
future germplasm collection, utilization, and conservation strategies in gene banks and introducing exotic
germplasm to widen the genetic base of the current lentil breeding population
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Correlation and path coefficient analysis of seed yield and yield components in Lentil (Lens culinaris Medik) genotypes in Ethiopia
No full textKnowledge of correlation among different traits and further partitioning of the correlation coefficients into direct and indirect effects on yield is one of the approaches to understand the nature and extent of the relationship among characters. The objective of this study was to determine the degree of associations between seed yield and yield components of lentil. In this study, 228 genotypes from diversified origin were considered. The experiment was conducted at three locations using randomized complete block design and augmented design. Significant strong positive phenotypic and genotype correlations were observed between seed yield and biomass, seed weight per plant, number of seed per plant and number of pods per plant. These four yield-contributing characters had also strong positive correlations with each other. The path coefficient analysis is in harmony, with the phenotypic and genotypic correlation, that is, seed weight per plant, followed by number of pods per plant, biomass yield and 100 seed weight have a considerable positive direct effect on lentil seed yield. However, days to 50% flowering, days to 90% maturity and rust disease severity score had negative phenotypic correlation and negative direct effect on seed yield
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