Análisis genético de caracteres agronómicos y de calidad de semilla en poblaciones de maíces criollos de México

"Se realizaron tres ensayos en el campo experimental del Instituto Tecnológico de Roque, en Celaya, Guanajuato, en el 2006, 2008 y 2009. El primero, fue solamente el incremento mediante polinización controlada de 10 colectas de maíces criollos de igual número de razas proporcionadas por el CIMMyT. En el ensayo dos y tres se utilizó el método I de Griffing, que involucra todas las cruzas posibles y los progenitores y se realizó el ANVA para calcular los cuadrados medios de los efectos de aptitud combinatoria general (ACG), aptitud combinatoria específica (ACE), efectos recíprocos (ER), efectos maternos (EM) y efectos no maternos (ENM), de acuerdo con el programa Diallel-SAS Método I, propuesto por Zhang y Kang (2003). Los genotipos fueron evaluados en campo, en un diseño de bloques completos al azar con dos repeticiones y en laboratorio en un diseño completamente al azar con cuatro repeticiones. Se evaluó el comportamiento agronómico de los progenitores, la calidad de la semilla, tolerancia a Fusarium, entre otras. En los híbridos F1 se determinó la calidad de la semilla, y se establecieron en campo para evaluar características agronómicas y del rendimiento. En los resultados del primer ensayo se determinaron grandes diferencias entre el germoplasma evaluado, debido principalmente a la precocidad, altura de planta, tolerancia a enfermedades, calidad de la semilla, entre otras. Con respecto al ensayo de la calidad de la semilla, el ANAVA mostró diferencias significativas para los genotipos, en los caracteres evaluados; encontrándose genotipos sobresalientes y otros con pobre comportamiento en estos parámetros. La ACG contribuye en mayor." "Three trials were conducted in the experimental field of the Instituto Tecnologico of Roque, at Celaya, Gto, at 2006, 2008 and 2009. The first was only increased by controlled pollination of 10 collections of creole maize of equal number of races provided by CIMMyT. In the essay two and three used the method I of Griffing, involving all possible crossing and parents and the ANVA was performed to calculate the square means the effects of general combinatory ability (GCA), specific combinatory ability (SCA), reciprocal effects (RE), maternal (ME) and not maternal effects (NME), in accordance with the program Diallel-SAS method I proposed by Zhang and Kang (2003). The genotypes were evaluated in field, laboratory and a design of full blocks random with two replicates a design completely randomly with four repetitions. We evaluated the agronomic performance of the parents, the quality of the seed, tolerance to Fusarium, among others. F1 hybrids the seed quality were tested, and were sown in field to evaluate agronomic characteristics and grain yield. The results of the first trial identified great differences between the germplasm assessed, mainly due to the earliness, tall plant, tolerance to diseases, seed quality, among others. With regard to the seed quality testing, the ANVA showed significant differences for the genotypes evaluated characters; finding outstanding genotypes and others with poor behavior in these parameters. The ACG contributes in greater proportion than the ACE in the analyzed traits and also maternal effects are observed. The best crosses to standard germination were involving the varieties of Jala, Pepitilla, Ancho pozolero and Tabloncillo landraces; in relation to the seed vigor in the best crossing involved the varieties Pepitilla, Ancho pozolero and Celaya. In the most important crossing for thousand seed weight, intervened the parent Ancho pozolero. In the experiment of the agronomic characterization of hybrids and their parents, the ANVA showed significant differences for genotypes, GCA and SCA for most of the variables. Additive genetic effects contribute in greater proportion than not additive effects. Reciprocal effects were observed in all the features except tall plant and prolificity, attributed mainly to maternal effects (reciprocal general); Bolita and Tabloncillo parents were the most early and Tuxpeño and Jala, the laters. Major grain yields estimator parents were for Tuxpeño and Celaya, for length of ear underlined the variety Jala, while thousand grain weight for Ancho pozolero. The specific crossing Tabloncillo by Pepitilla and Pepitilla by Tabloncillo showed adverse effects on female flowering and for male flowering were Tabloncillo by Bolita and Tabloncillo by Dulce. For grain yield the most outstanding crossing were Tepecintle by Dulce and Celaya by Tuxpeño, for length of ear the crossing Dulce by Jala and Jala by Bolita presented the estimator more high, and the weight of thousand grains the participation of the parent Ancho pozolero generated more positive estimators high."