ABSTRACT
Plants (N = 102) from 23 populations of Talinum, representing five morphologically similar species, were examined in a test of the hypothesis that ploidal level may be correlated with levels of Crassulacean acid metabolism. When grouped by species and ploidal level, two groups of tetraploid plants, T. calcaricum and tetraploid individuals of T. calycinum, had significantly greater malic acid accumulations than any other group, including diploid individuals of T. calycinum. Another tetraploid, T. teretifolium, did not show greater malic acid fluctuations than the diploids, including two putative ancestors (T. mengesii and T. parviflorum). Similarly, malic acid fluctuations in tetraploid individuals of T. parviflorum were not different from diploid individuals of the same species. Nonetheless, when all plants were compared, nocturnal accumulations of malic acid in tetraploid plants were significantly greater than those of diploid plants.
