"Natural crossing" of white clover by bees
1943
Atwood, S.S.
When eight clones of white clover which differed significantly in degree of pseudo-self-compatibility and which were recessive for two marker characters were crossed under bee cages during two years with other clones homozygous for these markers, the percentage crossing ranged from 85.0 to 100.0 for different cages and was significantly different for the eight clones. A slight inverse relationship may exist between the degree of pseudo-self-compatibility and the amount of crossing. Increased precision was gained when the percentage crossing was adjusted by analysis of covariance according to number of seeds per head or percentage germination. In the case of a self-compatible clone, the percentage crossing was only 18.8, but several lines of evidence suggested that this should be a minimum rather than a maximum estimate for the clone. Since such widely different amounts of crossing may be expected within the species, it is evident that all clones should be investigated thoroughly at least for their self-compatibility before including them in a breeding program.
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