Genotypes from 26 white clover lines differing widely in origin and morphology were cloned and examined at 2 phosphate (P) levels. Results were expressed by plotting yield at high P against yield at low P to obtain Hv.L diagrams, and by calculating L./H ratios. Differences among lines were small and indicated that little variation existed among lines for differences in P nutrition. However, high L/H ratios tended to be associated with the small-leaved plant type. Wide apparent variation was found among 460 unreplicated genotypes but the possibility that this variation was entirely environmental has not yet been investigated. Examination of genotypes falling in different regions of the Hv.L diagram revealed few morphological differences between groups selected for greatest difference in L/H ratios. The group with highest L/H ratio had considerably longer primary stolons and a greater fresh weight production per node. When replicated over several P levels these groups showed no differences in P response. A number of methods was used to analyse genotypic variation in P nutrition. Results indicated that some variation may exist.
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