Tuesday, 7 October 2008
George R. Brown Convention Center, Exhibit Hall E
The objective of this study was to determine the genetic control of the productive and qualitative characteristics of plants and corn silage. For this, an experiment was installed with 45 hybrid combinations obtained from the diallel crosses between ten commercial hybrids and with four checks in the city of Viçosa, Minas Gerais, Brazil. General (GCA) and Specific (SCA) Combining Ability of parents were significant to the characteristics of dry matter yield (DMY) and crude protein (CP) indicating additives and non-additives gene effects were important in the genetic control. Only GCA was significant for characteristics plant height (PH), productivity of whole plant yield (WPY) and percentage of hemicellulose (HCEL) showing the only additives gene effects were important in the genetic control, which suggests the use of recurrent selection. The combining ability and averages components of the cell wall, neutral detergent fiber (NDF) and acid detergent fiber (ADF) did not differ significantly between the hybrid combinations. Mean NDF ranged from 33.87% to 49.26% and the mean of ADF ranged from 15.47 to 23.96%, values considered appropriate for the production of silage quality. The cultivars P 30F90 and SHS 4070 are the most suitable for increasing the average characteristics HP, WPY and DMY while 2B619 and DKB466 for crude protein (CP) and BRS3003 and AG1051 to reduce HCEL percent. The hybrid combinations XB8028 x DKB466, XB8028 x P30F90, AG1051 x 2B619 and, Pointer 5 x AG1051 are the most promising for the formation of base population for breeding programmes for the improvement of corn silage quality. The strategy of breeding will be the selection cycle for HP, WPY and, HCEL and obtaining hybrids to optimize DMY and CP. The introgression of other genetic backgrounds is important to increase the means and genotypic variability for the higher of quality of silage.