Date of Award
Doctor of Philosophy
Populations of BC(,0)F(,2)- to BC(,4)F(,2)-derived sorghum lines from six wild x cultivated matings were evaluated for grain yield and other agronomic and morphological traits in south central India. Means of backcross generations theoretically will change linearly with backcrossing; genetic variances generally will be similar in the BC(,0) and BC(,1) and then decrease. Genetic variances depend on the numbers of plants backcrossed, selfed and evaluated. However, experimental results deviated significantly from these patterns. Mean grain yield and plant height changed nonlinearly with backcrossing; genetic variances for grain yield, plant height, kernel weight, and days to flower were highest in the BC(,1) or BC(,2). Epistasis is the most plausible explanation of the results;Lines exceeding the recurrent (cultivated) parents in grain yield by an average of 15% occurred in four matings; however, the frequency of transgressive segregation was low;Principal component analysis showed that restrictions to recombination of wild and cultivated traits exist, but are not strong.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Thomas Stanton Cox
Cox, Thomas Stanton, "Introgression of wild germplasm into cultivated sorghum " (1983). Retrospective Theses and Dissertations. 7705.