We describe the segregation of nuclear DNA content among the F2 progeny of hybrids between perennial teosinte with a higher DNA content (31.64 A.U. and 2n = 40) and Zea mays (Gaspe) with lower DNA content (23.21 A.U. and 2n = 20).

These hybrids were obtained by Magoja (MNL 52:37, 1978). The mean nuclear DNA content of the F2 progeny is 41.08 A.U. and so far corresponds to the analysis of 15 plants. Comparing this value to the mean DNA content in the F1 progeny of 41.35 A.U., it does not differ significantly.

The F2 nuclear area is 46.44 µ², which is significantly greater than the F1 area (39.9 µ²). From the nuclei analyzed, the densities (DNA content/nuclear area ) were determined establishing for the F2 a value of 0.9401, which is lower than that obtained in the F1 (1.046).

The preliminary results so far obtained on F2 plants allow us to believe that due to chromosomal recombination and reorganization, the DNA content may have a range of variation that may exceed its progenitors' extremes (Fig. 1).

The aim of this paper is to be able to relate morphological and physiological characters to the DNA content in segregating individuals.

Figure 1.

Ida Graciela Palacios

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