04056naa a2200205 a 450000100080000000500110000800800410001910000240006024500480008426000090013230000110014152034260015265000110357865000130358965000170360265000090361965300110362865300120363977301990365114616522004-10-15       1999    bl uuuu     u00u1 u    #d1 aTOLEDO, J. F. F. de  aStrategies for reaching future yield goals.  c1999  ap.133.  aBrazilian soybean breeding programs have reached their yield objectives, with continuous annual genetic gains which  have benefited soybean producers. The actual yield increases are sometimes reduced because of diseases such as the frog eye leaf spot (Cercospora sojina), stem cancer (Phomopsis phaseoli f.sp. meridionalis) and by soybean cyst nematode (Heterodera glycines). These problems, however, have along the years bee quickly solved by a team of researchs who developed resistant and competitive cultivars to take the place of old ones. Such yield increases show that there was genetic variability to be exploited. Recent studies have shown that genetic variability continues to exist for the important traits, and therefore, the annual gain rates should be maintained. Some changes in the focus of the Brazilian soybean breeding programs may happen in the medium term because of a growing demand for high nutritional quality, pesticide free soy products. Consequently, the relative importance of some soybean specific traits such as high oil/protein quality and content, disease and insect resistance start to be as important as high grain yield. The striking success of Embrapa's soybean breeding program over the past few years, with the release of highly adapted and yielding cultivars that are sowed in over 70% of the Brazilian fields, was based on its test capacity on all the locations which were intended to be cropped. It also depended on an established structure for seed multiplication and marketing of the cultivars to the farmers. These conditions were met through partnerships with soy seed producers grouped in Privately Funded Foundations located in the most important producer states. A soybean breeding program developed by a single company within a specific region, could hardly cover the Brazilian territory efficiently. Meeting all the regional demands is an impracticable task for a breeding program based on only one of the Brazilian regions. During 1998, of 24 released cultivaries 21 were developed in partnership with seed producers from the states: Rio Grande do Sul; Goias; Mato Grosso; Mato Grosso do Sul and Minas Gerais and also from the North/Northeast region (Tocantins, Maranhao and Piaui states). the results of this work are also coming out in the form of constant annual increases in the Brazilian soybean yield, which is mostly due to the genetic advances. The cultivars have also been the main transference vehicle of other technologies developed by projects of other research areas. The development of cultivars using the traditional breeding techniques has bee capable of solving the problems to date. It is an activity which began more than ten thousand years ago and wich has existed professionally for about a hundred years. It is clear that it must exist as such for a long time yet. Recently, however, new tools emerging as the result of the development in various areas of knowledge have being aggregated. These tools were, in a greater or lesser degree, used together with traditional techniques known for the development of superior genotypes. The advance in genetic techniques, including gene introgression from other species in soybean, the use of molecular markers and for quantitative methods together with the advance and easy access to information technology, has made possible to meet some of the breeding demands that would have been impracticable before.  aBrazil  abreeding  aMelhoramento  aSoja  aBrasil  aSoybean  tIn: WORLD SOYBEAN RESEARCH CONFERENCE, 6., 1999, Chicago. Proceedings: invited and contributed papers and posters. Chicago: University of Illinois / Soybean Research & Development Council, 1999.