Clematis

Abstract: A survey was conducted over several years in Italy and the Balkans in order to gain an understanding of the relationship between the Flavescence doree (FD) phytoplasma isolates found in clematis and grapevine. A total of 399 clematis and 107 grapevine samples were analyzed. The results showed that 36% of the Clematis vitalba plant samples were infected by phytoplasmas which, in grapevine, are associated with FD, a quarantine disease in Europe. Infected clematis plants were also found in areas where FD phytoplasma had never previously been reported to infect grapevine, such as Macedonia, Croatia and some areas of Italy and Serbia. Molecular data from three phytoplasma genomic fragments showed the presence of different FD phytoplasma isolates, all belonging to the 16SrV-C subgroup, including the Italian FD-C isolate, the isolate found in Serbia, an isolate similar to the French FD2000 and a new isolate typical of central Italy. A few clematis plants were infected with single nucleotide polymorphism, insertion or deletion mutants of the FD-C isolate. Of all the potential Hemipteran vector species surveyed in Italy and Serbia, only 18 of 527 Dictyophara europaea individuals tested proved to be infected with the FD phytoplasma. Preliminary transmission experiments showed that this species is able to transmit the FD phytoplasma from clematis to grapevine. The presence of FD-infected clematis and of D. europaea could, therefore, constitute a risk for FD epidemics in the European viticultural regions.

Abstract: The epidermal microcharacters of 20 genera in the Ranunculaceae and 10 outgroup genera from the families Glaucidiaceae, Circaeasteraceae, Berberidaceae, Menispermaceae, and Lar- dizabalaceae were studied employing scanning electron and light microscopy. Characters such as type of trichome and stomatal length are valuable tools in assessing phylogeny in the Ranunculaceae. Using cladistic analyses, the basic division of the family into two major groups according to chro- mosome size (R- and T-types) was confirmed. By outgroup polarization, the T-type chromosome group is considered most primitive. Two major clades are recognized in the T-type taxa: the Aquilegia and Thalictrum group including closely related genera and a group consisting of Coptis and Xan- thorhiza. Hydrastis is not consjdered a member of the Ranunculaceae. Further cladistic analyses of the R-type taxa using macrocharacters derived mainly from floral and fruit morphology resulted in the following subdivisions: the Anemone and Ranunculus group including Pulsatilla, Hepatica, and Clematis; the Cimicifuga and Actaea group; and the Helleborus group including Eranthis, Trollius, and Caltha. The Ranunculaceae, a large and varied fam- ily, consist of approximately 66 genera and 2000 species (Takhtajan 1987). Members of the family are distributed throughout the world, but are centered in the temperate and cold regions of both hemispheres; representatives are uncom- mon in tropical and subtropical zones except in montane regions (Ziman and Keener 1989).