Evaluation of a Population of Soybean Genotypes With Implications for Improving Self-Pollinated Crops1
- W. D. Hanson,
- A. H. Probst and
- B. E. Caldwell2
Eight improved soybean lines constituted the base of a random intermating population from which a population of homozygous genotypes was obtained. A family structure was maintained in the selfing generations. The genetic variability found was generally larger than that reported for two parent crosses. Considerable epistatic variability was suggested for seed yield, maturity, and percent mottling. The relative proportions for genetic variability partition were not affected when levels of environmental sampling, ranging from within environments to among environments in Maryland and Indiana, were considered. Concepts for improving a base population of homozygous lines through recurrent selection and intermixing were developed. Such an intermating system provided for stepwise improvement yet minimized the coefficient of parentage among breeding lines. The expected improvement in the base population resulting from intercrossing of the superior lines was developed. Selecting the top 20 lines (5%), intermating, and selfing in this study yielded a predicted 235 kg/ha (3.5 bu/A) gain over the base population mean. With epistatic variability, as suggested for seed yield, considerations for isolating unique genetic combinations become important. The importance of creating populations where geneticrecombinations could potentially occur was discussed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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