ABSTRACT
Rice (Oryza sativa L.) is a versatile crop globally, though it has relatively short history of production and research in Ethiopia. Hence, genetic improvement is of paramount importance to increase the production and productivity of the crop, which requires understanding of genetic variability in the crop. The study was conducted during 2017/2018 main cropping season at Fogera, Ethiopia, to determine the magnitude of genetic variability for yield and yield related traits in 30 lowland rice genotypes. The experiment was laid out using randomized block design with three replications. Data were collected for 17 agronomic characters and analysis of variance revealed significant differences among the genotypes for all characters. Grain yield ranged from 2766.7 to 7062 kgha-1 with a mean of 4736.13kgha-1.Genotypes G26 (7062kg), G14 (6900kg), G8 (6583.1kg), G27 (6486.9kg), G29 (6400.6kg) and G30 (6343.1kg) were found to be high yielding. The genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) ranged from 8.44 and 8.53 for days to maturity to38.30 and 39.37 for number of unfilled grains panicle-1. Broad sense heritability value ranged from 77.45% for number of panicles per plant to 99.16 % for plant height. Characters viz. days to heading, days to flowering, tillers plant-1, panicle plant-1, culm length, panicle length, plant height, flag leaf length, flag leaf width, filled grains panicle-1, unfilled grains panicle -1, panicle weight, biomass, grain yield and harvest index had high heritability and high genetic advance as percent of mean, showing presence of additive genes and selection based on these traits would be successful. For future, six rice genotypes with grain yield above 6 tons ha-1 have been identified and are recommended to advance further towards release as new varieties. Moreover, the future rice research should be supplemented by molecular characterization to further confirm the obtained current results.

ABSTRACT
The purpose of this study is to assess the microbiological characteristics of white cheese supplemented with Ziziphus spina-christi and Cinnamomum zeylanicum essential oils during the storage period. The cheese was made from warmed (45°C) raw cow milk with Ziziphus spina-christi and Cinnamomum zeylanicum oils added, and after manufacture, the cheese was kept in sterile plastic bags at 4°C for 21 days, and microbiological tests were performed at 1, 7, 14 and 21-day intervals. Results showed that total viable bacteria (TVB), Staphylococcus aureus, and yeasts and moulds counts were significantly lower in cheese supplemented with both oils, according to the findings. The concentration of oil had a significant effect on the counts, with TVB, S. aureus, yeasts and moulds, and coliform bacteria counts being significantly higher in the control cheese and significantly lower in the cheese supplemented with 0.5% Ziziphus spina-christi oil. The storage period of cheese made with Ziziphus spina-christi and Cinnamomum zeylanicom oils had a significant effect on TVB, coliform bacteria, and S. aureus counts. The microbial counts were significantly affected by the concentrations of 0.3% and 0.5% Ziziphus spina-christi oil during the storage period, except for yeasts and moulds, which were unaffected by the 0.3% Ziziphus spina-christi oil. The counts of microbes in cheese supplemented with 0.3% and 0.5% Cinnamomum zeylanicom oils decreased significantly as the storage period progressed. The study concluded that essential oils, as natural antimicrobials, could be useful in preserving cheese made traditionally from raw milk without the addition of starter culture.