Biology subjects

Kebede, M.

Publications and source records attributed to Kebede, M..

3 recordsLinked to original sources

bioRxiv2026

Genetic diversity and population structure of Ethiopian taro Colocasia esculenta (L.) Schott) as revealed by SSR markers

Abstract Taro (Colocasia esculenta (L.) Schott) is an important root and tuber crop that contributes to food security and livelihoods, but its genetic diversity remains poorly characterized in Ethiopia. This study assessed Ethiopian taro genetic diversity and population structure using simple sequence repeat (SSR) markers. We analyzed 119 accessions, 79 collected from farmers fields and 40 from the Ethiopian Biodiversity Institute (EBI), representing three regional populations: South Ethiopia Regional State (SERS), South West Ethiopia Peoples Regional State (SWEPRS), and Oromia. Fifteen polymorphic SSR markers produced 199 reproducible polymorphic loci, with 100% polymorphism. Polymorphism information content (PIC) ranged from 0.300 to 0.888 (mean 0.583). Diversity based on scored binary marker states was relatively low, with a mean effective number of alleles (Ne) of 1.077 and expected heterozygosity (He) of 0.066. Across populations, He ranged from 0.047 to 0.061, and the percentage of polymorphic loci ranged from 37.14% to 82.57%. Analysis of molecular variance showed that 98% of molecular variation occurred within populations and 2% among populations. Genetic differentiation ({Phi}PT, proportion of molecular variation among populations) was weak but significant ({Phi}PT = 0.016, P = 0.016). Principal coordinate analysis, neighbor-joining (NJ), and unweighted pair-group method with arithmetic mean (UPGMA) clustering showed extensive overlap among accessions and no clear geographic structuring. Bayesian clustering identified two groups as the strongest partition according to the {Delta}K criterion, but substantial admixture occurred, and groups did not correspond clearly to geographic populations. Despite relatively low diversity at individual scored loci, all 119 accessions had unique multilocus genotypes, indicating high multilocus genotypic diversity. Most molecular variation occurred within rather than among regional populations, potentially reflecting planting-material exchange and predominantly clonal propagation. These findings provide a basis for conserving, characterizing, and utilizing Ethiopian taro germplasm in crop improvement.

genetics↗

bioRxiv2024

Intercontinental dissemination and diversification of Xanthomonas perforans in tomato production

Emerging and re-emerging plant diseases continue to present multifarious threats to global food security. Considerable recent efforts are therefore being channeled towards understanding the nature of pathogen emergence, their spread and evolution. Xanthomonas euvesicatoria pv. perforans (Xep), one of the causal agents of bacterial spot of tomato, rapidly emerged and displaced other bacterial spot xanthomonads in tomato production regions around the world. In less than three decades, it has become a dominant xanthomonad pathogen in tomato production systems across the world and presents a model for understanding diversification of recently emerged bacterial plant pathogens. Although Xep has been continuously monitored in Florida since its discovery, the global population structure and evolution at the genome-scale is yet to be fully explored. The objectives of this work were to determine genetic diversity globally to ascertain if different tomato production regions contain genetically distinct Xep populations, to examine genetic relatedness of strains collected in tomato seed production areas in East Asia and other production regions, and to evaluate variation in type III effectors, which are critical pathogenicity and virulence factors, in relationship to population structure. We used genome data from 270 strains from 13 countries for phylogenetic analysis and characterization of Xop effector gene diversity among strains. Our results showed notable genetic diversity in the pathogen. We found genetically similar strains in distant tomato production regions, including seed production regions, and diversification over the past 100 years, which is consistent with intercontinental dissemination of the pathogen in hybrid tomato production chains. Evolution of the Xep pangenome, including the acquisition and loss of type III secreted effectors, is apparent within and among phylogenetic lineages. The apparent long-distance movement of the pathogen, together with variants that may not yet be widely distributed, poses risks of emergence of new variants in tomato production.

microbiology↗

bioRxiv2021

Stress Resistance Heat Shock Protein 70 (HSP70) Analysis in Sorghum (Sorghum bicolor L.) at Genome-Wide Level

Heat shock proteins (HSP70) play an important role in many biological processes. However, as typical in Sorghum bicolor, the systematic identification of the HSP70 gene is very limited, and the role of the Hsp70 gene in the evolution of Sorghum bicolor has not been described systematically a lot. To overcome the gap, Insilco analysis of HSP70 gene family was conducted.The investigation was utilizing the bioinformatics method to analyze the HSP70 gene family and it has been identified that 30 HSP70 genes from the genome sequence of Sorghum bicolor. A comprehensive analysis of these 30 identified genes undertaking the analysis of gene structure, phylogeny, and physicochemical properties, subcellular localization, and promoter region analysis. The gene structure visualization analyses revealed that 22 genes contains both 5 and 3 UTRS and one 5 and one 3 gene and 6 genes without UTR. The highest number of introns was recorded as 12 and those genes have shown that without in any intron. In the promoter region analysis, ten protein motifs are identified and characterized and 2219 cis-acting elements are identified. Among those, the promoter enhancer elements share the highest number (1411) and light-responsive elements share the next value (335). The physicochemical properties analysis revealed that 23 families have an acidic nature while four families are basic and the rests are neutral. In general, the different analyses performed disclosed their structural organization, subcellular localization, physicochemical properties, cis-acting elements, phylogenetic, and understress conditions. This study provides further information for the functional characterization of HSP70 and helps to understand the mechanisms of abiotic stress tolerance under diverse stress conditions in Sorghum bicolor.

plant biology↗