03371naa a2200265 a 450000100080000000500110000800800410001910000260006024500520008626000090013830000110014752025870015865000110274565000130275665000130276965000120278265000170279465000090281165300110282065300120283170000260284370000180286970000190288777301990290614617142004-10-15       1999    bl uuuu     u00u1 u    #d1 aFARIAS NETO, A. L. de  aSoybean breeding program in brazilian savannas.  c1999  ap.497.  aThe savanna region in Brazil (Cerrados), traditionally explored for extensive beef cattle production, today it is the major grain production area in Brazil, with about 10 million ha. Incorporation of 'Cerrados' into the Brazilian agricultural production was based on governmental incentives directed to farmers and on strong public investments on research. EMBRAPA, 'Brazilian Agricultural Research Enterprise', had an important role to overcome the major limitations for agricultural activities in this area, by turning soybeans an important crop in this frontier. Soybean breeding has been a continuous process to improve yield and important agronomic characters such as seed quality, insect and disease resistance. Late flowering cultivars, adapted to low latitudes was the first achievement by local breeding programs and the main factor  to soybean development in the region. However, the crop expansion increased the number and intensity of diseases such as bacterial pustule (Xantomonas phaseoli pv. glycines) and frogeye leaf spot (Cercospora sojina) in the 80's. The former has been practically excluded from the cultivars, since at least one resistant parent is included in all crosses. In the early 90's, breeding for resistance to stem canker (Diaporthe phaseolorum f.sp meridionalis) and soybean cyst nematode (Heterodera glycines) became important objectives. Adapted cultivars such as 'Dourados', 'IAC-12', 'IAC-13' and 'BR16' are sources of resistance to stem canker and backcrossing is the method most used to develop resistant cultivars. Breeding for resistance to soybean cyst nematode (SCN) whose genetic control of is polygenic and complex, has used American resistant sources. The first SCN resistant cultivar is 'MG BR-46 Renascenca' released in 1996. Other diseases and pest such as Powdery Mildew (Microsphaera  diffusa), target spot (Corynespora cassicola), sudden death syndrome (Fusarium solani f. sp glycines) and root-knot nematodes (Meloidogyne incognita, M. javanica and M, arenaria) are economically important in the region and sources of resistance are now under investigation. More recently, efforts have been made to develop cultivars of different maturity groups for diversified cropping systems. Medium-maturity cultivars'MG BR-46 Conquista', BRS-62 Carla', and 'BRS-158 Milena' were released in the last three years. It's expected that with a new law on protection of breeders rights, private enterprises and foundations will invest in soybean breeding and seed production, resulting in high cultivar availability and seed markert competition.  aBrazil  abreeding  asavannas  aCerrado  aMelhoramento  aSoja  aBrasil  aSoybean1 aSOUZA, P. I. de M. de1 aSPEHAR, C. R.1 aMOREIRA, C. T.  tIn: WORLD SOYBEAN RESEARCH CONFERENCE, 6., 1999, Chicago. Proceedings: invited and contributed papers and posters. Chicago: University of Illinois / Soybean Research & Development Council, 1999.