Mitochondrial DNA sequence variation in the spruce budworm species complex (Choristoneura: Lepidoptera)

A combination of polymerase-chain-reaction amplification and automated DNA sequencing was used to survey variation in a species complex of pest insects, the spruce budworms (Choristoneura fumiferana species group), and an outgroup species, C. rosaceana. We sequenced an mtDNA region of 1,573 bp that extends from the middle of cytochrome oxidase subunit I (COI) through tRNA leucine (UUR) to the end of cytochrome oxidase subunit II. In addition, we examined levels of intraspecific variation within a 470-bp region of the COI gene. Choristoneura fumiferana clearly represented the oldest lineage within its species group, with 2.7%-2.9% sequence divergence from the other species. In contrast, the four remaining species (C. pinus, C. biennis, C. occidentalis, and C. orae) had closely related or identical mtDNA, with < 1% divergence among most of their haplotypes. Despite its older lineage and widespread geographic distribution, C. fumiferana showed significantly lower intraspecific genetic diversity than did C. occidentalis. Choristoneura orae shared haplotypes with C. occidentalis and C. biennis, and species-level separation of these three species was not supported. Two divergent, uncommon haplotypes were also found in C. occidentalis and C. biennis. The divergent haplotype in C. biennis had an unusually high number of inferred amino acid replacements, suggesting selective differences between mitochondrial DNA haplotypes. Transition:transversion ratios in Choristoneura paralleled those found in Drosophila; transition:transversion ratios were highest in closely related sequences but decreased with increasing sequence divergence. Nucleotide composition showed an A+T bias that was near the high end of the range known for insects. This work illustrates the potential utility of direct DNA sequencing in assessing population structures, species limits, and phylogenetic relationships among organisms that have not previously been subjected to DNA analysis.      

A Synthetic Medium for Comparative Nutritional Studies of Lactobacilli

The composition of a synthetic medium supporting the growth of lactobacilli is given (Table 1). The medium, containing glucose, amino acids, vitamins, mineral salts, purines and pyrimidines, allows the study of nutritional requirements of different strains of lactobacilli under identical environmental conditions. It was found that all the strains tested needed L-glutamic acid, L-valine and L-leucine, and a group of them also required L-arginine, L-tyrosine and L-tryptophan. Some strains required vitamins, e.g. L. bulgaricus (pantothenic acid), L. fermenti (pantothenic acid and niacin). These results are compared with those found by others employing different media.     

Monocaryotization of Cultures of Lenzites trabea (Pers.) Fr. and other Wood-destroying Basidiomycetes

Cultures of Lenzites trabea and some other basidiomycetes grownon nutrient agar containing high concentrations of sodium arsenateconsistently reverted from the dicaryotic to the monocaryoticcondition. This effect could also be induced by a wide varietyof other toxicants, including copper sulphate, zinc sulphate,sodium dichromate, sodium pentachlorophenate, creosote, crystalviolet, boric acid, and sodium taurocholate, but sodium arsenatewas the most reliable monocaryotizing agent, being effectivewith eight of the fourteen basidio-mycete species tested withit. The neohaplonts formed by sodium arsenate and other toxicantsmate normally with each other and with compatible monosporeisolates. The value of chemical monocaryotization as a techniquein fungal genetics and experimental taxonomy is discussed. Byusing the mating factor alleles as genetic markers, it was demonstratedthat when L. trabea is monocaryo-tized by sodium arsenate orcopper sulphate, only one of the two nuclei in the dicaryoncan be recovered in the neohaplonts, the direction of this completenuclear selection depending on the toxicant and the dicaryonconcerned. It was shown to occur in treated wood blocks duringroutine soil-block decay tests of inorganic wood preservativesand it is probably a frequent, though hitherto unrecognized,occurrence in the laboratory testing of wood preservatives andother fungicides against basidiomycetes.     

Phosphorus benefits of different legume crops to subsequent wheat grown in different soils of Western Australia

Certain legume crops, including white lupin (Lupinus albus L.), mobilise soil-bound phosphorus (P) through root exudates. The changes in the rhizosphere enhance P availability to these crops, and possibly to subsequent crops growing in the same soil. We conducted a pot experiment to compare phosphorus acquisition of three legume species with that of wheat, and to determine whether the legume crops influence growth and P uptake of a subsequent wheat crop. Field pea (Pisum sativum L.), faba bean (Vicia faba L.), white lupin (Lupinus albus L.) and wheat (Triticum aestivum L.) were grown in three different soils to which we added no or 20 mg P kg^–1 soil (P0, P20). Growth, P content and rhizosphere carboxylates varied significantly amongst crops, soils and P levels. Total P content of the plants was increased with applied phosphorus. Phosphorus content of faba bean was 3.9 and 8.8 mg/pot, at P0 and P20, respectively, which was about double that of all other species at the respective P levels. Field pea and white lupin had large amounts of rhizosphere carboxylates, whereas wheat and faba bean had negligible amounts in all three soils at both P levels. Wheat grew better after legumes than after wheat in all three soils. The effect of the previous plant species was greater when these previous species had received P fertiliser. All the legumes increased plant biomass of subsequent wheat significantly over the unplanted pots in all the soils. Faba bean was unparalleled in promoting subsequent wheat growth on all fertilised soils. This experiment clearly demonstrated a residual benefit of the legume crops on the growth of the subsequent wheat crop due to enhanced P uptake. Faba bean appeared to be a suitable P-mobilising legume crop plant for use in rotations with wheat.     

Morphological and functional aspects of volatile-producing glands in bees (Hymenoptera: Apidae)

Abstract In this paper we focus on the occurrence and morphological aspects of exocrine glands in several bee species. Morphology of head labial, mandibular, Dufour, and abdominal tegumentar glands was investigated under light microscopy, scanning electron microscopy and transmission electron microscopy. Most of such glands present cells with cytoplasm homogeneous and acidophilic, or contain small apparently empty vacuoles. The cytoplasm cells' ultrastructure showed a well developed smooth endoplasmic reticulum, many polymorphic mitochondria, rare Golgi, lipid droplets, myelin figures, and many basal and apical plasma membrane infoldings. All these results are discussed in the text.     

On the identity of turmeric: the typification of Curcuma longa L. (Zingiberaceae)

Although Curcuma L. (Zingiberaceae) is a conserved name, with C. longa L. as its conserved type, the type of C. longa is still uncertain. Numerous discussions about the identity of the taxon called C. longa by Linnaeus have been followed by various attempts to rename turmeric, suggestions as how to settle the type and proposals to conserve the name from a later author in order to stabilize the situation. Unfortunately, none of the previous proposals can be upheld for reasons which are discussed in this article. A lectotype is selected from extant material examined by Linnaeus and an epitype collected near the type locality is designated here. The identity of C. longa is discussed and a colour plate of the species is included. Synonyms of C. longa and their types are discussed and notes on the variability of C. longa are provided.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 37–46.     

Occurrence of secretory structures in underground systems of seven Asteraceae species

In contrast with the abundance of anatomical studies of secretory structures on aerial vegetative organs of Asteraceae species, the information about secretory structures on thickened subterranean organs is sparse. The aim of this study was to investigate the occurrence of secretory structures on thickened and nonthickened subterranean organs of seven Asteraceae species from three tribes: Eupatorieae (Chromolaena squalida and Gyptis lanigera), Vernonieae (Chresta sphaerocephala, Lessingianthus bardanoides, L. glabratus and Orthopappus angustifolius), and Plucheeae (Pterocaulon angustifolium). The specimens were collected in areas of cerrado from the State of São Paulo, Brazil. All species of the tribe Vernonieae studied exhibited endodermic cells, other than the epithelial cells of the canal, with secretory activity in the roots. In C. sphaerocephala roots, two types of endodermic cell were found, but only one had secretory activity. Secretory canals were found in the tuberous and nontuberous roots of all studied species. These data agree with the results from the literature for Asteraceae species. Here, we describe for the first time in Asteraceae the presence of secretory idioblasts in C. sphaerocephala. Secretory trichomes are present in the Orthopappus angustifolius rhizophore. Histochemical tests have shown that all types of secretory structure possess substances containing lipids. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 789–796.     

Characterization of a prospective human model for study of the reproductive hormone responses to major illness

With critical illness, serum testosterone levels fall markedly, whereas estrogen levels rise. Although animal studies suggest adaptive advantages, no prospective model has been available for studies in humans. We hypothesized that coronary artery bypass graft (CABG) surgery would provide such a model by eliciting the same reproductive hormone and other endocrine responses as reported with major nonsurgical illnesses. We further hypothesized that those responses would occur consistently in all CABG patients with predictable time courses, providing reliable windows for prospective studies. In 17 men undergoing CABG, serum levels of reproductive hormones, cortisol, thyroid hormones, and IGF-I were measured before and for up to 5 wk after surgery. Changes in serum levels of reproductive and other hormones were similar to those reported in nonsurgical critically ill patients. Time course for onset, duration, and recovery of reproductive hormone changes were consistent among all patients. A window for studying the testosterone and estrogen responses was established as the first 5 days following CABG. Practical use of this model was demonstrated by evaluating, in another seven men, changes in gonadotroph responsiveness to GnRH following CABG. Finally, to determine whether our findings in CABG could be extended to other surgeries, we demonstrated similar endocrine responses in 12 men following abdominal aortic aneurysm resection. We conclude that patients undergoing CABG surgery provide a useful human model for the prospective evaluation of the reproductive axis responses to acute illness. Other major surgeries are likely to also be suitable for these studies.