Instituto Agronomico

Allometric genetics X. A three point test involving a gametophyte gene (Ga10 A2 Bt)

--Luiz Eugenio Coelho de Miranda and Luiz Torres de Miranda

In MNL 64:34-35, using data reported by J. Gonella, J and P. A. Peterson, PA with two kinds of families of backcrosses in the presence and absence of Ga10, we have developed a solution for the problem. In the present report a solution is presented for the case of having only one kind of family, that is, two marker factors segregating in the presence of the gametophyte factor. The original data from the authors cited are in the presence of the gametophyte factor: A2 Bt = 378, A2 bt = 7, a2 Bt = 117, and a2 bt = 253.

We have shown by allometric genetics that the calculus of the recombination of the markers is straightforward.

So the distance q between A2 and Bt is directly obtained as (A2 bt + a2 Bt)/n.

With the values presented we have the sum total of A2 = 385, a2 = 2,270, Bt = 495 and bt = 2,160. With these values the expectations by the proposed solution are as presented in Table 1, together with the algebraic and numeric calculations.

Table 1. Data as presented by P. A. Peterson and J. Gonella in MNL 49:71-73 in their Table 1. The expectations of the segregation as presented by L. T. de Miranda and L. E. C. de Miranda in MNL 64:34-35 and subsequent algebraic steps. p is the recombination Ga10 A2, and q those of A2 Bt. a is the allometric coefficient of Ga10.

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