Using nine microsatellite loci, we investigated genetic structure and diversity in 83 Brazilian cassava accessions, including several landraces, in the Cerrado biome in Mato Grosso do Sul, Brazil. All nine loci were polymorphic, averaging 6.00 alleles per locus. Treating each of seven municipalities as a cassava group or population, they averaged 3.5 alleles per locus, with 97% polymorphic loci, high values for observed heterozygosity (0.32) and gene diversity (0.56). Total genetic variability was high (0.668), and most of this genetic variability was concentrated within municipalities (0.577). Cluster and structure analyses divided accessions into two major clusters or populations (K = 2). Also, a significant genetic versus geographic correlation was found (r = 0.4567; P < 0.0260). Migratory routes in the Cerrado are considered main contributors to the region's high cassava diversity and spatial genetic structure, amplifying interactions between traditional farmers and the evolutionary dynamics of this crop.

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CYANIDE ACID CONTENT IN PROGENIES FROM CROSSES OF BITTER ANDSWEET CASSAVA CULTIVARS Cassava varieties are popularly separated by taste as bitter or sweet cultivars. Roots of bitter cultivars have a high HCN content (over 100 mg HCN equivalent/kg fresh roots) and are consumed only after processing, as flour, starch and other products. Sweet cultivars have low HCN content and can be consumed without any kind of processing. With the purpose of studing the possibility of using bitter varieties in the breeding of sweet cassava varieties, crosses were made between the different types of varieties to verify the cyanogenic profile of the segregating progenies. Two sweet varieties and a bitter variety (SRT-1330 Xingu) were pollinated by a sweet variety (SRT-797 Ouro do Vale). Crosses

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). A fabácea (leguminosa) cobriu por completo as entrelinhas da mandioca, demonstrando seu potencial de controle à erosão e a ervas espontâneas. O consórcio triplo mostrou-se vantajoso tendo em vista que a receita obtida com a venda do milho verde justificaria os custos da irrigação, além dos benefícios da inclusão do caupi e da não interferência dos consortes na produtividade da mandioca.Palavras-chave: Manihot esculenta, consórcio, adubação verde, agricultura orgânica.