02062naa a2200181 a 450000100080000000500110000800800410001910000150006024500650007526000090014052015620014970000160171170000160172770000150174370000180175870000160177677300880179216518162004-04-07       1998    bl uuuu     u00u1 u    #d1 aSANCHEZ, O  aApplication of AFLP for genetic characterization of cassava.  c1998  aAbstract: Cassava Bacterial Blight (CB-B), major disease in Latin America and Africa, is caused by Xanthomonas axonopodis pv. Manihot (Xam). Resistance is thought to be polygenic and additively inherited. 93 -varieties of Manihot esculenta (Crantz) from the cassava core collection CIAT went analyzed by AFLPs (Amplified Fragment Length polymorphism), and for ressistance to cassava bacterial blight. AFLP analysis was performed on all plant material using two primer combinations. A level of 79,2% polymorphism was found. The phenogram obtained shows betwe 74% and 96% of genetic similarity among all cassava accessions analyzed, The analysis permitted unique identification of  each individual indicating that the sample used does not contain genetic duplicates. Variation in the reaction to Xam strain (strains CIAT 1177 and  OrstX27) was observed among the 93 varieties tested for resistance to CBB. The correlation coefficient between resistance to Xam strains under controlled conditions was 0.53 suggesting the independence of resistance to each strain. Multiple correspondence analysis showed a random distribution of the resistance/susceptible response, with respect to overall genetic diversity measured by AFLP. A total heterozygosity index was calculated to find the diversity within clusters as among them. Our results demonstrate that AFLP anaysis is an effective means of providing quantitative estimates of genetic similarities among cassava accessions. We also demonstrate that resistance to CCB is broadly distributed in cassava germplasm.1 aRESTREPO, S1 aDUQUE, M. C1 aFREGENE, M1 aBONIERBALE, M1 aVERDIER, V.  tRevista Brasileira de Mandioca, Cruz das Almasgv.17, p.43, nov., 1998. Suplemento.