Abstract

Jatropha curcas L. is a Euphorbiaceae characterized as drought tolerant, with low nutrient exigency and resistant to pests and diseases; furthermore, its seeds have a high content of good quality oil, which makes it a potential plant species for biodiesel production. The association of J. curcas with arbuscular mycorrhizal fungi (AMF) may enhance some of these promising features. The aim of this work was to assess AMF community associated with different genotypes of J. curcas (different accessions of a germoplasm bank) grown in the same area and in plants of the same genotype grown in different regions to identify promising fungi in this association. The AMF community was assessed by morphological analysis and by polymerase chain reaction-denaturing gradient gel electrophoresis fingerprinting approach (PCR-DGGE) and sequencing of 18S rDNA. Twenty-seven species of AMF were identified morphologically, in addition to five additional ones identified by sequencing of DGGE bands. In both analyses, some genera and species were found in common, including Glomus and Acaulospora. In the same accession or in samples obtained from the same genetic material, but cultivated in neighboring regions, the AMF community had a greater similarity, showing a possible influence of the genetic material and of climatic conditions on the AMF community. Regardless of the AMF community, these plants present a high percentage of mycorrhizal colonization and a relatively high number of AMF spores, suggesting an important relationship with mycorrhizal association.

Key words: Nested PCR-DGGE, Jatropha curcas, arbuscular mycorrhizal fungi (AMF) community, Glomus, spore morphology.