Genetic Variability, Correlation and Path Coefficient Analysis of Ethiopian Mustard (Brasica Carinata A.Braun) Genotypes

The genus Brassica of Brassicaceae family as a whole is believed to have originated around the Mediterranean, Eastern Afghanistan and the adjoing portion of Pakistan and North-Eastern Africa (Hemigway, 1976). The genus includes six economically important species, namely, Brassica rapa, B. oleracea, B. nigra, B. juncea, B. napus, and B. carinata (Doweny and Röbbelen, 1989). Ethiopian mustard is believed to be originated in the highlands of the Ethiopian plateau and the adjoining portion of East Africa and the Mediterranean coast (Gomez-Campo and Prakash, 1999). The genus Brassica includes economically important species that provide oil for human consumption and raw materials for the industry, source as leaf and root vegetables and used for fodder and condiments (Getinet et al. 1991). Ethiopian mustard is important as source of oil and as a leafy vegetable in mid altitude and highland areas, (1700 to 2800 meters a.s.l). At its early stage of development the leaf is used as vegetable either by thinning or topping and seed can be also harvested from the same plant for oil extraction and other uses that include: greasing traditional bread baking clay pan (Mitad), curing certain ailments and preparing beverages (Alemayehu, 2001). In Ethiopia research on mustard started in the late 1960s by Ethiopian Institute of Agricultural Research with objective of developing highyielding mustard genotypes in increased of oil contents and meal quality. In doing so the breeding approaches for Ethiopian mustard improvement remained confined to selection and recombination followed by selection. To address this challenge for a better breeding program, it should have a broad genetic base. The success of any breeding program depends upon the genetic variability existed in the breeding material. The assessment of parameters including phenotypic and genotypic coefficients of variation, heritability in a broad sense, and genetic advance as a percent of the mean is a pre-requisite Abstract: The experiment was carried out to assess genetic variability, trait association and path coefficient analysis for Ethiopian mustard genotypes in order to select the desired plant types for high yield, oil and their components. The experiment was carried out in Randomized Complete Block Design in three replications at Holetta Agricultural Research Centre. The results of combined analysis indicated that studied traits of genotypes for yield and its related component traits were highly and significantly different for all traits compared. This revealed that there was a considerable magnitude of variability among the different genotypes for all the traits except for Seed yield per plant, number of secondary branches and plant height. In genetic variability, heritability and genetic advance analysis yield per plot (52432.72, 286770.34), oil yield (11754.25, 57297.33), number of seeds per plant (155.7286, 2611.72), days to flowering (21.62, 68.03) showed high phenotypic and genotypic variances, respectively indicating that the genotypes could be reflected by the phenotype and the effectiveness of selection based on the phenotypic performance for these traits. Oil (33.30%), days to flowering (31.78%), days to maturity (30.94%), exhibited high heritability estimates. In genotypic correlation coefficients yield per plot showed significant and positive correlation with oil yield (0.971), seed yield per plant (0.825), date of maturity (0.588) and date of flowering (0.577) which indicates that taking into account these traits as selection parameter will be an effective way to increase seed yield, and oil yield. Analyzed value from genotypic coefficient of variation, heritability and genetic advance, correlation co-efficient and path coefficient, oil yield, seed yield per plant, date of flowering and maturity, number of seeds per plant, number of primary branches, plant height and number of secondary branches were the traits which could be considered for future mustard crop breeding program.