02451naa a2200241 a 450000100080000000500110000800800410001910000200006024501390008026000090021952017480022865000110197665000190198765000150200665000190202165000230204065300110206365300240207470000190209870000170211770000170213477300580215116590742010-02-26       2008    bl uuuu     u00u1 u    #d1 aCOSTA, D. da C.  aPathogenicity and genetic variability of Radopholus similis populations in bananas (Musa acuminata AAA and AA) based on RAPD analysis.  c2008  aThe burrowing nematode (Radopbolus similis) is considered the most economically important nematode to banana production worldwide. In Brazil, yield losses can reach up to 100 % among Cavendish bananas. Although no information is available on genetic and biological variability of the nematode in Brazil in bananas and other plants, observations have suggested the occurrence of several biotypes of the nematode. The objective of this study was to observe genetic variability of 12 populations of R similis using RAPD markers, in relation to geographic origin and aggressiveness on diploid (AA) and triploid (AAA) banana genotypes. This study showed that all populations of R similis reproduced in all banana genotypes, and higher values for the reproduction factor occurred on Grand Naine, Pisang Jari Buaya, and Yangambi km 5. Differences in aggressiveness were reflected on plant height and root weight. Populations from Bahia (BA1 and BA2), Minas Gerais (MG1 and MG2), Pernambuco (PE), Cuba (CUB), and Costa Rica (CR) were more aggressive on banana plants, in particular those from Pernambuco and Bahia. By contrast, populations from Rio de Janeiro (RJ), São Paulo (SP1 and SP2), Santa Catarina (SC), and Australia (AUS) were less aggressive. Through RAPD markers at the relative genetic distance of 0.45, the populations of R similis were separated in five similarity groups. No correlation between geographic proximity and genetic similarity was observed among R similis populations, except for the populations from Bahia (BA1 and BA2). In this study it was evidenced a close association between the level of aggressiveness on bananas and a short genetic distance, except for the populations from Rio de Janeiro (RJ) and Australia (AUS).  aBanana  aMusa acuminata  aNematóide  aPatogenicidade  aRadopholus similis  aBrasil  aVariedade genética1 aFALEIRO, F. G.1 aCARES, J. E.1 aGOMES, A. C.  tNematologia brasileiragv. 32, n. 4, p. 303-316, 2008