Degree Type

Dissertation

Date of Award

1983

Degree Name

Doctor of Philosophy

Department

Agronomy

Abstract

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.

DOI

https://doi.org/10.31274/rtd-180813-5397

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Thomas Stanton Cox

Language

en

Proquest ID

AAI8323274

File Format

application/pdf

File Size

172 pages

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