Systematic anatomy of vegetative organs of the Hydrocharitaceae

The anatomy of the Hydrocharitaceae is described in relation to the modes of life of the family. Leaf morphology depends on the ecology of the species. The xylem is simple with relatively primitive characters, but the phloem shows a contradictory evolutionary trend, possessing the highly evolved characters of large, wide sieve-tube elements with more or less horizontal, simple sieve-plates and a single companion cell to each element. Characters of taxonomic value within the family exist but are lewer and less satisfactory than those in families such as the Cyperaceae; such characters are the shape of the axillary scales, the pattern of occurrence of tannin secretory cells and the diaphragm cells of roots.
A microfiche of data and plates of illustrations not printed in the journal is available.     

Chorion patterns on eggs of Lutzomyia sandflies from the Peruvian Andes

Abstract. Scanning electron microscopy (SEM) was used to depict and describe the eggs of five species of phlebotomine sandfly from the Andean region of Peru: Lutzomyia caballeroi, Lu.noguchii, Lu.peruensis, Lu.tejadai and Lu.verrucarum. Two new types of chorionic sculpturing of sandfly eggs are reported: these were named disperse (Lu.tejadai) and verrucose (Lu.noguchii). The aeropylar area of the eggs is also described for the first time for neotropical sandflies. These character states appear to vary for ecological rather than phylogenetic reasons and could be used for species identification.     

Next-generation sequencing and metagenomic analysis: a universal diagnostic tool in plant virology

A novel, unbiased approach to plant viral disease diagnosis has been developed which requires no a priori knowledge of the host or pathogen. Next-generation sequencing coupled with metagenomic analysis was used to produce large quantities of cDNA sequence in a model system of tomato infected with Pepino mosaic virus . The method was then applied to a sample of Gomphrena globosa infected with an unknown pathogen originally isolated from the flowering plant Liatris spicata . This plant was found to contain a new cucumovirus, for which we suggest the name 'Gayfeather mild mottle virus'. In both cases, the full viral genome was sequenced. This method expedites the entire process of novel virus discovery, identification, viral genome sequencing and, subsequently, the development of more routine assays for new viral pathogens.     

Leptepsilonema gen. n. (Nematoda, Epsilonematidae) from Chile and the Caribbean Sea

The new genus Leptepsilonema is erected. L. procerum sp.n from intertidal sandy beaches of the Caribbean sea and L. macrum sp.n. and L. exile sp.n. from Chile are described. Postembryonal development of L. procerum , covering the juvenile stages II-IV, is presented. Some ecological data are added.     

Interaction Between Cryopreservation, Rewarming Rate and Seed Humidification on the Germination of Two Spanish Endemic Species

The effects of humidification, storage in liquid nitrogen (1or 30 d) and rewarming rate on seed germination were studiedin two Spanish endemics. Humidification resulted in higher germinationpercentages only in the species with hard covers, especiallyin slowly rewarmed seeds. In an experiment lasting 21 weeks,seeds stored in liquid nitrogen were removed for 10 min eachweek to mimic the withdrawal of samples from a seed bank; thishad no effect on germination.Copyright 1998 Annals of BotanyCompany Centaurea hyssopifolia,Limonium dichotomum, cryopreservation, cypsela, endemics, germination, humidification, seeds.     

Use of partially engorged female ticks as laboratory animals in microbiological research

Abstract. Partially engorged female ticks were used as laboratory animals in microbiological research. The ticks, which were inoculated intracoelomally, became a convenient substrate for the detection of viruses, rickettsiae and protozoal parasites. This research concerned the isolation of newly recovered micro-organisms, the study of development, structure and distribution of microbial agents in ticks, and the study of their interaction with other pathogens or symbionts during mixed infection in a tick body. The isolation and maintenance of Rickettsiella phytoseiuli , the organism not of tick-borne origin, was achieved. For use in Central Europe the tick Dermacentor reticulatus is recommended for the above investigations.