Comparative Study of Fatty Acids Profile in Eleven Wild Mushrooms of Boletacea and Russulaceae Families

Eleven species of wild mushrooms which belong to Boletaceae and Russulaceae families were examined by gas chromatography (GC) and gas chromatography–mass spectrometry (GC/MS) analysis for the presence of fatty acids. As far as we know, the fatty acid profiles of B. purpureus and B. rhodoxanthus were described for the first time. Twenty‐six fatty acids were determined. Linoleic (19.5 – 72%), oleic (0.11 – 64%), palmitic (5.9 – 22%) and stearic acids (0.81 – 57%) were present in the highest contents. In all samples, unsaturated fatty acids dominate. Agglomerative hierarchical clustering was used to display the correlation between the fatty acids and their relationships with the mushroom species. Based on the fatty acids profile in the samples, the mushrooms can be divided into two families: Boletaceae and Russulaceae families, using cluster analysis.     

密褶红菇化学成分研究

从红菇科密褶红菇(Russula densifolia)的子实体中分离得到15个化合物,经波谱分析鉴定为D-阿洛糖醇(1)、硬脂酸(2)、3-羧酸呋喃(3)、(22E,24R)-3β-hydroxyergosta-5,22-diene(4)、3β-hydroxy-5α,8α-epidioxy-24β-methylc．holest-6-ene(5)、琥珀酸酐(6)、3β-hydroxy-5α,8α-epidioxyergosta-6,22-diene(7)、软脂酸(8)、尿嘧啶(9)、顺丁烯二酸(10)、硫代乙酸酐(11)、1,4．丁二酸(12)、1-乙基-β-D吡喃葡萄糖苷(13)、2-aeetamino-2-deoxy-／3-β-glucose(14)和cembrosideB(15)。     

l-2-Amino-4-methylpimelic acid: A new amino acid from Lactarius species

A PC survey revealed the occurrence of an unusual amino acid in fruit bodies of the mushroom Lactarius quietus Fr. and a related species. This was identified as l-2-amino-4-methylpimelic acid, which has not been previously reported as a naturally occurring compound.     

Ectomycorrhizal fungi diversity in a white sand forest in western Amazonia

The genera Dicymbe and Aldina (Fabaceae) host ectomycorrhizal fungi (EcM) and are common in white sand forests (WSFs), a highly specialized habitat with a high level of plant endemism compared with terra-firme forests. In this study, we visited four times a 1-ha permanent plot established in a small patch of a WSF in the south of Colombia Amazonia. Forty-eight species of EcM fungi were recovered from sporocarps and 15 ITS species-level were detected from root tips. Seventeen species were new reports to Colombia and seven corresponded to undescribed species. These results confirm that this WSF supports a significant EcM fungal diversity. Most of the species found in this study have been previously reported to be associated with other legume and/or dipterocarp species from geographically distant forests. The long-distance occurrence combined with low host specificity, suggest the possibility of gene flow between geographically distant populations of EcM fungi in neotropical lowland rainforests.     

Further advances in orchid mycorrhizal research

Orchid mycorrhizas are mutualistic interactions between fungi and members of the Orchidaceae, the world’s largest plant family. The majority of the world’s orchids are photosynthetic, a small number of species are myco-heterotrophic throughout their lifetime, and recent research indicates a third mode (mixotrophy) whereby green orchids supplement their photosynthetically fixed carbon with carbon derived from their mycorrhizal fungus. Molecular identification studies of orchid-associated fungi indicate a wide range of fungi might be orchid mycobionts, show common fungal taxa across the globe and support the view that some orchids have specific fungal interactions. Confirmation of mycorrhizal status requires isolation of the fungi and restoration of functional mycorrhizas. New methods may now be used to store orchid-associated fungi and store and germinate seed, leading to more efficient culture of orchid species. However, many orchid mycorrhizas must be synthesised before conservation of these associations can be attempted in the field. Further gene expression studies of orchid mycorrhizas are needed to better understand the establishment and maintenance of the interaction. These data will add to efforts to conserve this diverse and valuable association.     

Sesquiterpenes from Lactarius blennius

Six sesquiterpene lactones were isolated from Lactarius blennius. The structures of two new sesquiterpenes, blennin A and blennin B were determinated by spectroscopic methods and the structure of the seco-compound, blennin C, is revised. The two known furan sesquiterpenes and lactarorufin A were also identified.     

Russula velenovskyi new to Japan,with phylogenetic implications of Russula species between Japanese subalpine forests and Northern Europe

To compare morphological characters and phylogenetic placement between Japanese and European Russula, 32 specimens of 12 species were collected from Japanese subalpine forests and Northern Europe. Several sequences of nrDNA ITS region (ITS) of these Russula species were obtained. High homological similarities were shown between ITS sequences of several Russula samples collected from Japanese subalpine forests, Europe and North America. These facts show distribution of the same Russula species among these areas. From morphological observations and phylogenetic analyses, two same Russula species, R. velenovskyi, and R. decolorans are found in Japan, Europe and North America. Of these, R. velenovskyi collected from Mt. Fuji, Mt. Nyukasa and Mt. Tateshina in mountainous area of central Honshu is reported as a new Japanese record.     

Mycorrhizal specificity in the fully mycoheterotrophic Hexalectris Raf. (Orchidaceae: Epidendroideae)

Mycoheterotrophic species have abandoned an autotrophic lifestyle and obtain carbon exclusively from mycorrhizal fungi. Although these species have evolved independently in many plant families, such events have occurred most often in the Orchidaceae, resulting in the highest concentration of these species in the tracheophytes. Studies of mycoheterotrophic species' mycobionts have generally revealed extreme levels of mycorrhizal specialization, suggesting that this system is ideal for studying the evolution of mycorrhizal associations. However, these studies have often investigated single or few, often unrelated, species without consideration of their phylogenetic relationships. Herein, we present the first investigation of the mycorrhizal associates of all species of a well-characterized orchid genus comprised exclusively of mycoheterotrophic species. With the employment of molecular phylogenetic methods, we identify the fungal associates of each of nine Hexalectris species from 134 individuals and 42 populations. We report that Hexalectris warnockii associates exclusively with members of the Thelephoraceae, H. brevicaulis and H. grandiflora associate with members of the Russulaceae and Sebacinaceae subgroup A, while each member of the H. spicata species complex associates primarily with unique sets of Sebacinaceae subgroup A clades. These results are consistent with other studies of mycorrhizal specificity within mycoheterotrophic plants in that they suggest strong selection within divergent lineages for unique associations with narrow clades of mycorrhizal fungi. Our results also suggest that mycorrhizal associations are a rapidly evolving characteristic in the H. spicata complex.     

乳菇属具褐色色素的2个新种:暗褐乳菇和橄榄褐乳菇

盖表皮或菌柄表皮具有褐色色素这一特征在乳菇属小红乳菇亚属Lactarius subg.Russularia中较为少见.文中描述了产于中国南部的2个子实体褐色、表皮中具有褐色色素的乳菇新种:暗褐乳菇L.atrofuscus和橄榄褐乳菇L.olivaceofuscus.其中,暗褐乳菇L.atrofuscus的孢子球形,盖表皮为(子实层)球囊型,缺乏大囊体;除褐色色素外,盖表皮和菌柄表皮中所具有的树脂样皮壳物质也是识别该种的关键特征.橄榄褐乳菇L.olivaceofuscus的表皮内色素为深橄榄褐色,缺乏树脂样皮壳物质;菌盖强烈皱缩,盖表皮末端菌丝细长,较大的孢子具有较高的条脊和翼,这些特征可以将其与暗褐乳菇和其他相近种相区别.文中提供了该2种的宏观形态和显微特征描述,以及与相近种的形态对比和真菌条形码ITS序列.