Resumen

CERVANTES ORTIZ, F et al. Genetic effect estimation related to seed and seedling vigor in Mexican tropical corns. Phyton (B. Aires) [online]. 2011, vol.80, n.1, pp.19-26. ISSN 1851-5657.

We determined the genetic components, and the correlation between the F₁ and the F₂ generations, for traits like seed and seedling vigor using a diallel crossing design. The study involved six tropical maize inbred lines from the CIMMYT. Crosses were formed in CIMMYT's Maize Research Station in Tlaltizapan, Morelos during the summer of 2004. In order to produce F₂ seeds, F₁ crosses were grown at Tepalcingo, Mor. and Iguala, Guerrero. This was accomplished by controlling pollinations (half sibs). Seeds from the F₁ and the F₂ crosses were evaluated at the Colegio de Postgraduados, Montecillo, Mexico. F₁ and F₂ seeds were used to perform a standard germination test. Seed vigor was evaluated after conducting a seed aging treatment, and conductivity and seed weight were also determined. A test for emergence on sand bed was also conducted. Variables recorded included percentage, speed and index of emergence; canopy dry weight; seedling height and vigor indexes I and II. Significant (p≤0.01) effects of the General Combining Ability (GCA) were observed for all traits in both the F₁ and F₂ generations. GCA effects were greater than those of Specific Combining Ability (SCA). The only exception was vigor after the accelerating age treatment for the F₁ seed. Maternal effects in the F₁ generation were significant (p≤0.01) for all characters. However, seedling height, canopy dry weight and vigor indexes I and II were not influenced by the female parent in the F₂ generation. Parents CML 396 and CML 407 had the highest GCA for seed vigor, while 245 CML expressed the same condition for seedling vigor traits in both generations for most traits evaluated. These materials might be considered for integrating a program of breeding for seed and seedling vigor. On the other hand, there was no direct and significant association of the GCA in the F₁ versus the F₂ generations for all evaluated traits.

Palabras clave : Zea mays L.; Combining ability; Genetic effects; Seed and seedling vigor.

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