Inbreeding and Heterosis in Red Clover1
- N. L. Taylor,
- Karl Johnston,
- M. K. Anderson and
- J. C. Williams2
The effects of inbreeding and heterosis in red clover (Trifolium pratense L.) were investigated in two experiments. Objectives were to study the effects of one generation of selfing on pseudo-self-compatibility (PSC) and on seed and forage characteristics, and to ascertain the degree of hybrid vigor obtained and its relation to persistence in single crosses of I1 parents.
In the first experiment, five I0 parental clones and four I1 clones from each of the five parents were compared in spaced-planted field plots for PSC, cross-compatibility, florets per head, and heads per plant. In all characteristics, some inbred families contained clones which equalled or exceeded their non-inbred parents.
In the second experiment, a diallel cross was made among four I0 clones, and another among four I1 clones (one from each I0). Plants from these crosses and from open-pollinated seed of the four I0's, and three varietal checks were compared for yield and persistence in spaced-planted field plots, which also included vegetative propagules of the four I0 and four I1 clones. Hybrid vigor was expressed in the I1 single crosses, but their yields were no greater than the single crosses of the parental I0 clones. I1 clones yielded as much and were as persistent as I0 clones, but both yield and persistence were less than other non-inbred materials, except for the varietal checks and O.P.'s of I0 clones. It was inferred that inbred parental lines may be maintained either by seed through PSC or by vegetative reproduction, and that yield and persistence lowered by selfing will be regained in single crosses.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .