The Journal of Agricultural Science

Research Article

Plant breeding studies in leguminous forage crops I. Natural cross-breeding in winter beans

James L. Fyfea1 and Norman T. J. Baileya2

a1 Plant Breeding Institute, School of Agriculture, University of Cambridge

a2 Department of Human Ecology, University of Cambridge

1. If a crop varies in respect to a character which shows simple Mendelian inheritance then it is possible to estimate the proportion of cross-fertilization within the crop from the data obtained by (i) drawing plants from the crop and scoring them in respect of the character, then (ii) growing their separate progenies and scoring them.

2. Maximum likelihood expressions are given for the estimation of p and f { = (1 — α)/(l + α)} from the genotypic classification of the parents and from the phenotypic classification of the progenies; where p is the gametic frequency of the dominant allel and α is the proportion of fertilizations in which the pollen is equally likely to come from any plant in the population.

3. When the above expressions are applied to a case in winter beans, in which the parent plants were selected for high yield it is found that the different estimates of p agree, but those of f do not.

(Received September 12 1951)