The effect of water activity and pH on the production of mycotoxins by fungi growing on a bread analogue

Mycotoxin production by various toxigenic fungi, growing on a bread analogue, was investigated at various water activities (a_w) and pH combinations. Citrinin, ochratoxin A and sterigmatocystin could be detected at a_w > 0·80, while patulin was only observed at a_w= 0·95. These results show that some toxins may be produced at lower water activities than have been reported on synthetic media and suggest that, where possible, natural substrates should be used to investigate factors affect-ing mycotoxin production in foodstuffs.     

Biology and phylogenetic relationships of Neophonus bruchi, an anomalous south Andean staphylinid (Coleoptera)

Abstract. The virtually unknown monotypic genus Neophonus Fauvel has been collected in several localities in south-central Chile; it was previously known only from the type locality in Argentina. Field observations of the adults on forest foliage and study of their gut contents suggest that they are mycophagous and eat primarily foliicolous fungi, a habit previously unknown in Staphylinidae. Their mouthparts and tarsi show morphological specializations apparently correlated with these habits. Larvae remain unknown. The phylogenetic relationships of the genus within the omaliine-group of Staphylinidae sensu lato are discussed.     

A revision of the marine algae of São Tomé and Principe (Gulf of Guinea)

In all 101 species and varieties of marine algae are mentioned for S. Tomé and Príncipe. These records arise from examination of the material in the herbarium of the Botanical Institute of the University of Coimbra, together with material collected in 1956 by Dr C. A. Thorold. From the latter material there are 17 new records for the island of S. Tomé.
No new species have been described, but Acantkophora ramulosa Kütz. is emended, and Bryopsis densa Pilger and Struvea multipartita Pilger are reduced to the synonymy of Bryopsis pennata var. secunda and Struvea anastomosans respectively.
Information on the climate and tides of the islands is given, and a series of 'seasonal coincidences' likely to influence coastal marine conditions is described for the Gulf of Guinea.     

STUDIES ON PLANT CUTICLE: THE CUTIN COMPONENT OF THE CUTICLES OF LEAVES

Methods are described for the chemical separation from leaf material of the ventral and dorsal surface cuticular membranes and for the determination of cutin in the membranes and leaf tissues.
The cutin contents of the cuticular membranes separated from leaves of laurel, rhododendron, and Euonymus , and of leaf tissues of cauliflower, red beet, banana, tomato, strawberry and blackcurrant are reported. The relationship between the cutin and waxy components of the leaf cuticle is discussed, and earlier work on the development, structure and chemistry of the cuticle is reviewed.     

冬虫夏草的寄主昆虫是虫草蝙蝠蛾

冬虫夏草原名夏草冬虫,简称虫草,是我国一味名贵药材。李时珍(1578)的本草纲目中未有记载。据考据此种药材在清朝雍正或乾隆年间才应用(中国药学大辞典,1958)。赵学敏(1756)的本草拾遗和吴遵程(177)的本草从新才把它记载为药材。四川通志、黔囊、文房肆考、柑园小识等书中早已提到,足见在民间府用已久。1723 年曾有法国人把标     

The diversification of South American murid rodents: evidence from mitochondrial DNA sequence data for the akodontine tribe

Phylogenetic relationships based on 801 base pairs (bp) of the mitochondrial cytochrome b gene are examined for eight genera and 28 species of the akodontine tribe of South American murid rodents. The akodontine tribe comprises some 35% of the total diversity of the subfamily Sigmodontinae, but the current taxonomy at virtually all levels is uncertain because of inadequate generic diagnoses and assessments of variation and trends in traditional morphological characters. Monophyly of the tribe cannot be resolved by the sequence data, based on comparisons to outgroup taxa in three other tribes (Oryzomyini, Phyllotini, and Thomasomyini). However, highly corroborated monophyletic units within the group are obtained in a variety of both parsimony and distance analyses. These include a redefined and numerically dominant genus Akodon (with Microxus and Hypsimys as synonyms), Bolomys, Lenoxus, Oxymycterus, and a strongly supported assemblage that includes the central Andean Chroeomys and 'Akodon' andinus and the southern Abrothrix, 'Akodon' olivaceus, and the long-clawed mice of the genera Notiomys, Geoxus, and Chelemys. Sequence divergence within species is typically less than 5%, although levels can reach 10% for some highly polytypic forms. Divergence among genera within the tribe reaches 35% in corrected estimates, a level that is as great as that among representatives of different tribes. Changes in the current classification of akodontines are suggested based on these data, and the timing and place of origin of the tribe and its radiation is discussed.     

Depolymerization of cortical microtubules is not a primary cause of chilling injury in corn (Zea mays L. cv Black Mexican Sweet) suspension culture cells

Cold-induced depolymerization of cortical microtubules were examined in suspension culture cells of corn (Zea mays L. cv Black Mexican Sweet) at various stages of chilling. In an attempt to determine whether microtubule depolymerization contributes to chilling injury, experiments were carried out with and without abscisic acid (ABA) pretreatment, since ABA reduces the severity of chilling injury in these cells. Microtubule depolymerization was detectable after 1 h at 4°C and became more extensive as the chilling was prolonged. There was little chilling injury after 1 d at 4°C in either ABA-treated or non-ABA-treated cells. After 3 d at 4°C, there was about 26% injury for ABA-treated and 40% injury for non-ABA-treated cells, as evaluated by 2,3,5-triphenyl-tetrazolium chloride reduction and by regrowth. After 1d at 4°C, less than 10% of cells retained full arrays of microtubules in both ABA-treated and non-ABA-treated cells, the remainder having either partial arrays or no microtubules. After 3d at 4°C, about 90% of cells showed complete or almost complete depolymerization of microtubules in both ABA-treated and non-ABA-treated cells. ABA did not stabilize the cortical microtubules against cold-induced depolymerization. In about 66% of ABA-treated cells and 57% of non-ABA-treated cells that had been held at 4°C for 3d, repolymerization of cortical microtubules occurred after 3h at 28°C. These results argue against the hypothesis that depolymerization of cortical microtubules is a primary cause of chilling injury.