01675naa a2200181 a 450000100080000000500110000800800410001910000180006024500830007826000090016152011760017065000120134665000130135865000200137165300140139170000190140577300690142415685962005-03-17       1999    bl ---       0--  u    #d1 aSHARMA, R. D.  aFitonematóides associados a genótipos de gergelim em condições de cerrado.  c1999  aDuring April 1993 a nematode survey was conducted in an experimental are of Embrapa Cerrados, Planaltina, Federal District of Brazil, where 21 genotypes of sesame (Sesamum indicum L.) were sampled for nematode presence. Four composite soil and root samples were collected from the rhizospheres of cach genotype before harvest. The nematodes were extracted from 100g of soil and 10g of roots utilizing modified Coolen's method. Seven species of plant-parasitic nematodes, with decreasing frequency of occurence in genotypes were: Pratylenchus brachyurus (100%), Aphelenchoides sp. (100%), Ditylenchus sp. (100%), Helicotylenchus dihystera (67%), Paratrichodorus minor (67%) and Criconemella ornata (48%). Two species of mycophagos nematodes were found, and their frequency of occurrence in genotypes was: Aphelenchus avenae (100%) and Tylenchus sp. (95%). Free-living nematodes were present in all the samples. The average population densities of P. brachyurus varied between 3 per sample for genotype Aceiteira SN 2 and 56 for genotype Seridó 01 SM2; H. dihystera, Criconemella ornata e P. minor population densities/sample, when found, were present in very low numbers.  aCerrado  aGergelim  aSesamum Indicum  aNematóde1 aAMABILE, R. F.  tNematologia Brasileira, Piracicabagv. 23, n. 1, p. 84-87, 1999.