Ecological-evolutionary relationships in Passiflora alata from Rio Grande do Sul, Brazil / Relações ecológico-evolutivas em Passiflora alata do Rio Grande do Sul, Brasil

The geographical distribution, ecological characteristics, flowering and fruiting times, and pollinating agents of Passiflora alata are considered and related to molecular genetic data gathered simultaneously. The first report on this species in Rio Grande do Sul was made in 1934, only in cultivated gardens. Approximately 20 years later, however, the species was already classified as efferata (wild) in Porto Alegre's suburbs. The data presented here, together with the DNA investigations, indicate that P. alata is actively colonizing previously unoccupied areas of this region.

A distribuição geográfica, as características ecológicas, as épocas de florescimento e frutificação, e os agentes polinizadores de Passiflora alata são considerados e relacionados a estudos genético-moleculares desenvolvidos simultaneamente. O primeiro registro da espécie no Rio Grande do Sul foi feito em 1934, apenas em área cultivada. Cerca de 20 anos depois, no entanto, a espécie já era classificada como efferata (selvagem) nos subúrbios de Porto Alegre. Os dados aqui apresentados, junto com as investigações de DNA, indicam que P. alata está colonizando ativamente áreas previamente não ocupadas desta região.

Evolutionary implications of infra- and interspecific molecular variability of pathogenesis-related proteins

We have examined phylogenetic relationships in seven pathogenesis-related (PR) protein families. Within-family comparisons involved 79 species, 166 amino acid sequences, and 1,791 sites. For 37 species, 124 different PR isoforms were identified (an average of 3.3 per species). Thirty-one of the 37 species investigated tended to cluster together (84 percent). Of the 17 clusters distinguished in the seven phylogenetic trees, 10 (59 percent) were in agreement with their taxonomic status, ascertained at the family level. The strong similarities among the intraspecific forms, as compared to interspecific differences, argue for some kind of gene conversion, but the rare occurrence of widely different isoforms also suggests diversifying selection. PRs 1, 6, and 4 seem to be less differentiated than PRs 3, 2, 10, and 5.