Studies on the breeding of self-pollinating cereals

Summary

The limitations of the pedigree and mass methods of selection in the improvement of self pollinating cereal crops are discussed and the value of quantitative data in the early generations of selection is emphasised. Two systems of selection which provide such data have been introduced at the Cambridge Plant Breeding Institute.

In one, known as the F₂ progeny method of selection, the progenies of selected F₂ plants are grown in yield trials without further selection during F₄, F₅ and F₆ after which single plant selections are made within the more promising progenies.

In the other system, known as the pedigree trial method of selection, normal pedigree selection is carried out in F₂ and F₃. In the F₄ generation single plants are selected from the better families for continued pedigree selection and within each of these families the remaining plants are bulked to give grain for a yield trial in the following year. This process is repeated in F₅ and F₆, the grain for trial being in each case obtained from the progeny rows and not from the preceding trial.

The use of these methods is illustrated by reference to wheat hybrids grown at Cambridge, and the data obtained is shown to be useful in comparing the value of different parental combinations as well as in assessing the relative merits of the selections within each cross.