World Journal of Agricultural Sciences

World Journal of Agricultural Sciences Vol. 4 (1), pp. 050-057, September 2016, ISSN 2329-9312©2015 World Science Research Journals 

Full Length Research 

Genetic Improvement in Oil Content and Associated Traits of Ethiopian Mustard (Brassica carinata Braun) Varieties in Ethiopia 

Mihret Yirgu and Tefera Regasa

*Corresponding author. E-mail: mihret.yirgu@mwu.edu.et  

School of Agriculture, Plant Science, Madda walabu University, P.O.X, 247, Bale-Robe, Ethiopia. 

Abstract

This study intended to identify changes in morpho-physiological characters associated with genetic improvement in oil content and estimate the amount of genetic improvement made over time in released Ethiopian mustard varieties. Eight Ethiopian mustard varieties have been released from 1976 to 2006 along with one local check (farmers’ variety) were evaluated. Average rate of increase in oil content per year of release was 0.07percentage and relative annual rate of genetic improvement was 0.18% per year over 36 years. The estimated annual rate of genetic improvement in protein content showed a negative and non-significant there was 0.03 percentages and relative annual genetic improvement -0.21% per year of the varieties released. The genetic improvement of oil content improvement of Ethiopian mustard over the last 36 years was significantly associated with increasing trend to variety release in thousand seed weight, grain and biomass yield, biomass production and seed filling rate. Oil content was positively and significantly correlated with thousand seed weight, grain yield, biomass production and seed filling rate, and harvest index. Thousand seed weight, plant height and seed filling rate was the most important character, which greatly contributed to the variation in oil content among the varieties. 

Key words: Association, Stepwise regression, Thousand seed weight