The 2C and 4C nuclear
DNA amounts were estimated in eight diploid species, belonging to three diverse genera (Vicia, Tephrosia, and Phlox) and their corresponding colchitetraploids. In P. drummondii, T. purpurea, and T. oxygona
tetraploids the deviation from the expectation was highly significant. The
DNA in P. drummondii was further discarded in subsequent (C1, C2) generations, thus attaining an overall reduction of about 25%. The
DNA content in the subsequent generations was the same as that of C2. It is concluded that rapid
DNA loss in the first and subsequent generations was not only associated with the substantial increase (30-66%) in the seed set, but it also helped in the establishment and stabilization of the
tetraploid. The possible relationship between such a nucleotypic change and success of
polyploids is discussed. The
DNA change from the expected value in the P. drummondii
tetraploid was achieved by equal decrement to each chromosome independent of size, i.e., small chromosomes loose the same amount of
DNA as the large chromosomes.