The environmental conditions in Madeira Island are favorable for the presence and dissemination of the pinewood nematode (PWN), Bursaphelenchus xylophilus. Five hundred Pinus pinaster wood samples were collected in several forest areas and PWN was detected in 22.8 % of the samples. Bursaphelenchus xylophilus isolates from Madeira Island displayed the species-specific diagnostic characters. A morphological variation in the female tail terminus was detected. In most females, the tail presented a broadly rounded terminus and, occasionally, a digitate terminus with a terminal nipple-like extension resembling a mucro. PCR ITS-RFLP analysis revealed that Madeira Island isolates exhibited patterns specific to the species B. xylophilus and similar to virulent isolates. Amplified ITS regions were further sequenced and no genetic diversity was found for this genomic region among 17 Portuguese isolates (Madeira Island and Continental Portugal). Phylogenetic analysis revealed that Portuguese isolates grouped with isolates from China, Korea and one isolate from Japan.

The root-lesion nematode, Pratylenchus goodeyi, is among the most economically damaging parasites of banana plants. Nematode control can benefit from searching for novel bio-nematicides. The present study was carried out to assess the potential nematicidal properties of two Solanum species (Solanum sisynibriífolíum and S. nigrum) against P. goodeyi, using dichloromethane, acetone, ethanol and either cold or hot water extracts of the plants. Water extracts of both plants at a concentration of 10 mg ml" ' greatly affected nematode movement and also caused mortality. The analysis of sequential extracts at the same experimental concentrations showed that, although water extracts affect nematode mobility and mortality, the acetone extract from S. nigrum was the most efficient, causing 100% mortality after 23 h exposure. The results showed that S. sísymbríífolíum and S. nigrum extracts contain chemical components that induce morphological changes in the body structure of the root-lesion nematode, affect mobihty and cause mortality. The nematostatic and nematicidal potential of the extracts described herein merit further studies to find novel bio-nematicides against the root-lesion nematode.

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Isolation and expression of effector genes encoding proteins secreted by plant-parasitic nematodes into a host can be helpful in improving the understanding of parasitic interactions. In this study, calreticulin, a highly conserved Ca 2+ -binding and multifunctional protein, and beta-1,4-endoglucanase, a cell wall-degrading enzyme, both known to be secreted from oesophageal gland cells and injected through the nematode stylet into host tissue, were analysed. Full-length cDNAs from calreticulin (crt) and beta-1,4-endoglucanase (eng) with an estimated size of 1549 and 1342 bp, respectively, were isolated from the root-lesion nematode Pratylenchus goodeyi (Pg) by RT-PCR and RACE techniques. Pg-crt and Pg-eng cDNAs were characterized in silico, and their expression assessed by semiquantitative PCR in nematodes exposed to a chemical stress provided by a Solanum nigrum extract showing nematicidal activity. It was demonstrated that the plant extract down-regulated the levels of Pg-crt mRNA, whereas the transcripts of Pg-eng mRNA held steady. This extract also affected nematode behaviour towards the roots since the number of nematodes that reached and penetrated the roots diminished when the exposure time rose. These observations indicate that the nematicidal compounds present in the plant extract were effective as a signal to influence the infection success of P. goodeyi in vitro and it might be tested against other phytoparasitic nematodes.

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