INCREASED YIELD FROM TRANSGRESSIVE SEGREGATES OF A STYLOSANTHES CAPITATA CROSS IN A TROPICAL OXISOL

The legume Stylosanthes capitata is native to poor acid soils of tropi cal savannas in eastern Brazil and Venezuela. Among accessions evaluat ed, CIAT 1019 and CIAT 1097 were predominantly autogamous with long-te rm persistence and stability. These were crossed and their progeny stu died intensively in large populations using pedigree selection, initia lly at the Carimagua Research Station of CIAT in Colombia, and finally at CPAC in Brazil. This resulted in the selection of transgressive se gregates with higher dry matter (DM) and seed yield than the parents, while maintaining anthracnose and stem-borer resistance. The final F-7 lines were selected in the CPAC Oxisol which contains high and low pe rcentage saturations of Al and Ca, respectively. The two best segregat es had 44% and 31% greater DM yields than 1019, the higher-yielding pa rent. All S. cagitata lines maintained high leaf mineral levels, espec ially Ca, in the poor Oxisol.