Effects of growth retardants on bulbil production by Narcissus twin-scales

Narcissus twin-scale propagules, cut from various positions in the parent bulb, were incubated with gibberellic acid (GA₃) or growth retardants. Bulbil production was inhibited in all cases by GA₃ at 10–100 mg/litre. Chlormequat chloride, chlorphonium chloride and paclobutrazol also inhibited bulbil production; in the case of paclobutrazol, outer twin-scales were more sensitive to lower concentrations of the retardant than inner ones. Ancymidol enhanced bulbil production (in numbers by up to 15%) in the outermost twin-scales, and had no stimulatory effect on the inner twin-scales. Treatments affected bulbil numbers and bulbil lengths about equally.     

Evaluation of Harmonic Direction-Finding Systems for Detecting Locomotor Activity

Abstract: We conducted a physical simulation experiment to test the efficacy of harmonic direction finding for remotely detecting locomotor activity in animals. The ability to remotely detect movement helps to avoid disturbing natural movement behavior. Remote detection implies that the observer can sense only a change in signal bearing. In our simulated movements, small changes in bearing (<5.7°) were routinely undetectable. Detectability improved progressively with the size of the simulated animal movement. The average (±SD) of reflector tag movements correctly detected for 5 observers was 93.9 ± 12.8% when the tag was moved ≥11.5°; most observers correctly detected tag movements ≥20.1°. Given our data, one can assess whether the technique will be effective for detecting movements at an observation distance appropriate for the study organism. We recommend that both habitat and behavior of the organism be taken into consideration when contemplating use of this technique for detecting locomotion.     

The effect of the CpTi gene in strawberry against attack by vine weevil (Otiorhynchus sulcatus F. Coleoptera: Curculionidae)

The degree of protection against insect feeding conferred upon transgenic strawberry lines expressing the Cowpea trypsin inhibitor was evaluated under glasshouse conditions. Insect bioassays were carried out using vine weevil (Otiorhynchus sulcatus) in two experiments and in both experiments there was a highly significant reduction in damage by weevil larvae on the transgenic lines.     

Species identification of Cecidophyopsis mites (Acari: Eriophyidae) from different Ribes species and countries using molecular genetics

Cecidophyopsis mites were studied by PCR amplification of parts of their ribosomal DNA, followed by restriction enzyme analysis. Mite specimens on Ribes nigrum (black currant) from six countries gave the same digestion pattern, which was distinct from the pattern for mites found on R. rubrum from Poland and Finland and for R. grossularia from the USA. This suggests that each Ribes species is host to a different mite species: C. ribis, C. selachodon and C. grossulariae, respectively. Two other mite samples from R. alpinum and R. aureum were identical but were distinct from each of the other species.     

Short-Term In Vitro Culture and Molecular Analysis of the Microsporidian, Enterocytozoon bieneusi

ABSTRACT. The microsporidium, Enterocytozoon bieneusi , causes a severe, debilitating, chronic diarrhea in patients with the acquired immunodeficiency syndrome. Specific diagnosis of intestinal microsporidiosis, especially due to Enterocytozoon , is difficult and there is no known therapy that can completely eradicate this parasite. Preliminary studies indicate that a short term (about 6 months) in vitro culture of this parasite yielding low numbers of spores, may be established by inoculating human lung fibroblasts and/or monkey kidney cell cultures with duodenal aspirates and or biopsy from infected patients. The cultures may subsequently be used for the isolation and molecular analysis of parasite DNA.