Agronomic traits variation in a hybrid among lines with mobile elements
--Luis B. Mazoti and Ana M. Broccoli
Mobile elements are useful in inducing genetic diversity. Such effects have evolutionary and breeding implications. Their distribution in important breeding lines suggests that they play a role in the endeavor to create better crops (Peterson, P. Breed. Rev. 4:81-121, 1986). We propose to investigate if variation in quantitative traits may be found by evaluating a hybrid derived from a mutational Ds-Ac type system and if such a variation is associated with mutation in aleurone layer color. The visible effect gene marker is C1, that controls anthocyanin production (colored aleurone) which by Ds-Ac action induces mutation to C1-I (colorless aleurone) (Mazoti MNL 40:62, 1966).
The female parent line had purple aleurone. We used seven pedigrees of the same S8 line derived from the Ds-Ac system as pollinator, and separated colorless kernel progenies (mutant) from purple ones (normal). Hybrid materials were evaluated over three years at the Instituto Fitotecnico de Santa Catalina by ear yield components in a Complete Randomized Design. ANOVA and Krushkali-Wallis analyses were used, considering the variable pollinator aleurone color as the main effect.
Descendants of colorless aleurone progenitors (mutants) showed greater yield potential than those of their siblings from purple aleurone parents. In the first and third year, excluding ear length, there were significant differences (P = 0.05) in favor of the colorless group. In the second year, with severe water stress, the traits ear diameter and hundred-grain weight gave statistical differences (P = 0.05) showing superiority of the purple group, so showing inverse behavior. This opens up the debate on the major aptitude for colorless genotype yield, demanding superior environmental quality to demonstrate its potential.
The variance values differ from group to group, suggesting a greater potential variation in the non-marker mutation purple group. An unexpected genetic component of variance appears among the simple hybrid combinations. Agronomic traits like yield aptitude and water stress response vary from group to group, showing distinct biological strategies under different environmental conditions.
These results suggest that this genetic material could generate diversity in traits of agronomic interest that can be useful in plant breeding programs.
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