Genotype Assay and Method of Moments Analyses of Five Quantitative Traits in a Spring Wheat Cross1
- D. K. Mulitze and
- R. J. Baker2
The purpose of this study was to evaluate the genotype assay procedure for estimating the number of genes governing quantitative traits. For comparison, numbers of genes were also estimated by applying the method of moments procedure to the same material. The genotype assay and method of moments procedures were used to estimate the number of genes controlling differences in spikelets/spike, kernels/spike, kernel weight, grinding time, and culm length between the spring wheat (Triticum aestivum L.) cultivar Cook and line NB125. A modified split-plot field experiment with 176 F5-derived families was conducted in each of 2 years at one location. Genotype assay analysis gave estimates of numbers of genes of 3 to 24+, 2 to 8, 2 to 8, 1 to 6, and 3 to 17 controlling spikelets/spike, kernels/spike, kernel weight, grinding time, and culm length, respectively. The method of moments gave estimates of 2 to 7, 4 to 7, 3 to 8, 2 to 9, and 6 to 10 for the same traits. Genotype-environment interaction contributed to variation in estimates from both methods. Genotype assay was sensitive to the level of Type I error used to test for variation among grandprogeny lines while the method of moments analysis was sensitive to the method used for estimating genotypic range. A general equation for estimating gene number by the method of moments from any generation within a cross of two inbred lines was developed. The advantages of using the method of moments in later generations was discussed. The method of moments applied to later generations may often be superior to genotype assay for estimating the number of genes affecting a quantitative trait.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .