Abstract : This paper presents a study regarding the protein content in five groups of single cross corn hybrids-resulting from a cross between inbred tester lines and isonuclear inbred lines. Experiments were carried out at ARDS Turda during 2009 and 2010. These hybrids were also tested for their general and specific combining ability, in order to identify those isonuclear inbred lines that show potential use in breeding programs for protein content improvement. The experimental model was polifactorial and included five comparative cultures from which two TC 209 and TC 243 had 28 plots and TC 221, TB 367 and D 105 with 21 plots. For the chemical analysis 50 g of corn kernels were weighed from the average probes and were finely ground. The resulting corn flour was used to determine the protein content. The chemical analyses were performed on samples obtained from self-pollinated corn ears, and open-pollinated corn ears, with INSTALAB 600. In all five comparative groups used for testing there were differences between the experimental years 2009 and 2010 that were statistically assured. Influence of cytoplasms on the variance was between 15 and 67%. In all five experimental situations the interaction with the experimental years was statistically significant. The proportion of the factors involved in the genotypic variance of the protein content (open pollinated) is presented in figure 2. Cytoplasm proportion was between 5% for TC 221 and 17% for TC 209, while the proportion for testers was 45% for TC 221, 72% for TC 209 and 73% for D105. For the hybrid combinations, the specific combining ability was between – 0.71% for the hybrid combination TC 243(cit. A 665) x TC 344 and + 0.83% for the hybrid combination TC 243 x TC 344. The results of this comparative culture revealed the proportion of the cytoplasmatic effects, additive effects of the testers and of the interactions between cytoplasm x nucleuses are relatively close. Our findings revealed that nuclear genes played a great role in the variance of protein content, but the cytoplasmatic and nucleo-cytoplasmatic interactions are also important.

protein content, isonuclear inbred corn lines, genic, cytoplasmatic and nucleo-cytoplasmatic interactions

Presentation: oral