Combining Ability and Heterosis in Corn Breeding Lines to Forage and Grain

Abstract

This study was conducted in two stages, in 2006 the formation of cross, in the experimental field of the Universidad Autonoma Agraria Antonio Narro Unidad Laguna (UAAANUL), and the evaluation of the same in 2007 ; at two locations with three environments, a locality was the experimental field of UAAANUL during spring and summer cycles and another location was the Niagara, Municipality of Aguascalientes, during the spring cycle. The genetic material used consisted of three groups of lines : the first group formed by four lines from the UAAANUL, the second group , two lines from INIFAP, and the third group , 10 lines of the International Center for Maize Improvement and Wheat (CIMMYT). The main objective was to estimate the effects of general combining ability (GCA) of the lines, and the specific combining ability (SCA) of their crosses and heterosis, to estimate its use in a breeding program. Estimates of general combining ability (GCA) and specific combining ability (SCA) were obtained using an analysis of line x line. To forage yield (FY), B-40 (16.84 t · ha -1 ) and AN-447 (1.54 t · ha -1 ) and to grain yield (GY), AN-388R (2.31 t · ha -1 ) had the grea test effect of GCA in both types of yield. The greatest effects of SCA for (FY) were cross AN- 447XCML-264 (17.56 t · ha -1 ) and AN-388RXCML-319 (16.54 t · ha -1 ), in (GY) were cross AN- 447XCML-315 (1.94 t · ha -1 ) and B-40XCML-319 (1.78 t · ha -1 ). For heterosis, higher value in forage yield was cross AN-447XCML-264 (20.7%), in grain yield, were B-40XCML-319 (27.1%) and B- 32XCML-319 (22.1%) crosses. These results show that it is possible to structure a hybrid program using best lines from CIMMYT, INIFAP and UAAANUL.