Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Genetic variation and gene effects of plant height, internode, and coleoptile length in crosses of tall and semidwarf durum wheats
Abstract
Genetic variations in plant height, internode and coleoptile length were investigated in durum wheats of diverse origin. Generation mean analysis was performed on mean data derived from seven durum wheat cultivars and derived populations (F1, F2, B1, and B2) grown at two locations in 1987 in Morocco, to determine the relative importance of the gene effects influencing plant height, internode and coleoptile length. Significant differences were observed for all internode lengths in tall and semidwarf parents. The height reduction in semidwarfs resulted from shortening all internodes, especially the lower internodes, IN3 and IN4. The peduncle contributed 40% to 50% of the plant height in semi-dwarfs, and 35% and 38% in tall cultivars. For all traits, additive effects predominated and ranged from 61% to 87% of the total variation for plant height and internodes length. For spike length, only the additive effects were significant and accounted for 43%. With minor expectations, additive, dominance, and to a lesser extent, additive x additive epistatic effects (aajj$\sp\prime),$ were important in controlling each of the traits studied. Additive effects were more susceptible to changes in the environment more than dominant effects while aajj$\sp\prime$ were relatively stable over both locations except for plant height. The genetic parameter estimates indicated the best line for the desired plant height morphology was Cocorit, which had high negative additive contribution for plant height and lower internodes (IN2, IN3 and IN4) and positive additive contribution in its progenies for length of the uppermost internodes. For coleoptile length, significant genetic variability was present in the seven parents. Only additive effects were significant for this character (83% of the total variation). Narrow sense heritability for all crosses averaged 25.6%. The tall cultivars would have a significant additive contribution for increasing coleoptile length of their progenies while the semidwarf cultivars would generally, but not always reduce coleoptile length. Hence not all semidwarfs have a negative contribution for coleoptile length of their progenies.
Subject Area
Agronomy|Genetics
Recommended Citation
Ouassou, Abdellah, "Genetic variation and gene effects of plant height, internode, and coleoptile length in crosses of tall and semidwarf durum wheats" (1991). ETD collection for University of Nebraska-Lincoln. AAI9219381.
https://digitalcommons.unl.edu/dissertations/AAI9219381