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Sorghum population breeding for intercropping with legumes
Abstract
Multiple cropping systems are used in much of the world; however, very little research has been done to breed specific cultivars for this type of environment. This study utilized 196 S1 lines in 1983 and 120 S1 lines in 1986 from two random mating sorghum (Sorghum bicolor (L.) Moench) populations planted in an intensive intercrop with a legume and in monoculture. Family and family by cropping system variance components were derived to calculate heritabilities and predicted gains from selection (per cycle) for grain yield, date of 50% anthesis, and plant height. Heritabilities estimated for yield in the intercrop (0.35-0.57) were lower than those estimated from the monoculture (0.57-0.84) as were the predicted gains from selection (4.4%-15.0% vs 12.5%-74.5%, intercrop and monoculture, respectively). However, yield tests of the cycle one population bulks showed that the selections based on intercrop performance (Cli) gave consistent yield increases over the selections based on monoculture performance (Clm) (non-significant in one population and significant at P = 0.076 in the other). Inbreeding depression was consistently lower in the Cli (3.8%) as compared to the Clm (7.2%). The S1 family by cropping system interaction was significant (P = 0.05) for the four populations tested. Heritabilities for date of 50% anthesis and were high (0.76-0.93) for all tested populations as were the heritabilities for plant height (0.65-0.85). No significant differences for these two variables were detected due to making selections in either cropping systems. A nearest neighbors type covariance analysis utilizing principal components analysis was used in 1986 to reduce the error mean square. Two thirds of the S1 families were unreplicated in 1986 to increase design efficiency. It is concluded that the evaluation of the lines in intercrop were more accurate and breeding of sorghum cultivars for intercropping with legumes needs to include some testing in intercrop to obtain the best genotypes.
Subject Area
Agronomy
Recommended Citation
Youngquist, Wayne Craig, "Sorghum population breeding for intercropping with legumes" (1987). ETD collection for University of Nebraska-Lincoln. AAI8803779.
https://digitalcommons.unl.edu/dissertations/AAI8803779