Worldwide phylogeny of Lactarius section Deliciosi inferred from ITS and glyceraldehyde-3-phosphate dehydrogenase gene sequences

A phylogenetic analysis of Lactarius sect. Deliciosi was performed based on collections of all known species. Several samples of each species were included, originating from a wide geographic range. The two DNA regions we used (ITS and a part of the gene encoding glyceraldehyde-3-phosphate dehydrogenase) showed an incongruent phylogenetic signal. Much attention was paid to carefully observed macro- and micromorphological characters to draw taxonomic conclusions. We currently accept 38 taxa (31 species and seven varieties) in Lactarius sect. Deliciosi worldwide; four species are new to science. More sampling is needed to resolve the status of the North American varieties. Our knowledge of the Asian species in this section remains fragmentary. The monophyly of the section and its position within Lactarius subgenus Piperites, as proposed in recent morphology-based classification schemes, is confirmed. The intrasectional relationships however do not coincide with the color of the latex (as previously supposed). Intercontinental conspecificity is low in general. The name L. deliciosus is wrongfully applied in North and Central America and only two species seem to occur in both Asia and Europe.     

Molecular phylogenetic biodiversity assessment of arctic and boreal ectomycorrhizal Lactarius Pers. (Russulales; Basidiomycota) in Alaska, based on soil and sporocarp DNA

Despite the critical roles fungi play in the functioning of ecosystems, especially as symbionts of plants and recyclers of organic matter, their biodiversity is poorly known in high-latitude regions. In this paper, we discuss the molecular diversity of one of the most diverse and abundant groups of ectomycorrhizal fungi: the genus Lactarius Pers. We analysed internal transcribed spacer rDNA sequences from both curated sporocarp collections and soil polymerase chain reaction clone libraries sampled in the arctic tundra and boreal forests of Alaska. Our genetic diversity assessment, based on various phylogenetic methods and operational taxonomic unit (OTU) delimitations, suggests that the genus Lactarius is diverse in Alaska, with at least 43 putative phylogroups, and 24 and 38 distinct OTUs based on 95% and 97% internal transcribed spacer sequence similarity, respectively. Some OTUs were identified to known species, while others were novel, previously unsequenced groups. Non-asymptotic species accumulation curves, the disparity between observed and estimated richness, and the high number of singleton OTUs indicated that many Lactarius species remain to be found and identified in Alaska. Many Lactarius taxa show strong habitat preference to one of the three major vegetation types in the sampled regions (arctic tundra, black spruce forests, and mixed birch-aspen-white spruce forests), as supported by statistical tests of UniFrac distances and principal coordinates analyses (PCoA). Together, our data robustly demonstrate great diversity and nonrandom ecological partitioning in an important boreal ectomycorrhizal genus within a relatively small geographical region. The observed diversity of Lactarius was much higher in either type of boreal forest than in the arctic tundra, supporting the widely recognized pattern of decreasing species richness with increasing latitude.     

中国南方地区松乳菇遗传多样性分析

松乳菇Lactarius deliciosus是一种对松树的生长具有重大意义的外生菌根真菌,具有很高的经济价值,因无法人工培育,过度的人工采摘造成产地生态的严重破坏。比较中国南方3个省9个不同地区的68个松乳菇的rDNA ITS区碱基序列的差异,以期研究各不同群体的ITS单倍体型多样性,不同地区群体之间的遗传关系,以及遗传分化与地理隔离的关系。遗传分析发现,得到的68个松乳菇样品的ITS序列可认定为7种单倍体型,这些单倍体型聚集为2个不同的系统进化群体,表现出两种不同的系统进化方向。7种单倍体型中,两个主     

Critical assessment of the Lactarius gerardii species complex (Russulales)

This paper investigates species delimitation within the Lactarius gerardii species complex and explores its taxonomic and geographical extent. A combined molecular phylogeny based on ITS, LSU and rpb2 gene sequences is constructed and morphological characters are evaluated. While L. gerardii was originally described from North America, it has later been reported from all over Asia. Therefore a worldwide sampling range was aimed at, including species exhibiting morphological affinities with L. gerardii. The phylogenetic analyses indicate that intercontinental conspecificity in L. gerardii is absent. Thirty strongly supported clades are retrieved of which 18 are morphologically identifiable species. The group is elevated to Lactarius subg. Gerardii stat. nov. It includes, apart from L. gerardii s.l., L. atrovelutinus, L. bicolor, L. ochrogalactus, L. petersenii, L. reticulatovenosus, L. sepiaceus, L. subgerardii and L. wirrabara, as well as the pleurotoid L. uyedae. The paraphyletic nature of the genus Lactarius is confirmed. Lactarius subg. Gerardii appears not affiliated with L.?subg. Plinthogalus and this can be substantiated morphologically. No representatives are known from Europe, Africa or South America. The high frequency of intercontinental sister relationships observed between America, Asia and the Australian region, suggests multiple migration and speciation events have occurred across continents.     

Mycorrhiza of the host-specific Lactarius deterrimus on the roots of Picea abies and Arctostaphylos uva-ursi

The ectomycorrhizal basidiomycete species Lactarius deterrimus Gröger is considered to be a strictly host-specific mycobiont of Picea abies (L.) Karst. However, we identified arbutoid mycorrhiza formed by this fungus on the roots of Arctostaphylos uva-ursi (L.) Spreng. in a mixed stand at the alpine timberline; typical ectomycorrhiza of P. abies were found in close relation. A. uva-ursi is known as an extremely unspecific phytobiont. The mycorrhizae of both associations are described and compared morphologically. The mycorrhiza formed by L. deterrimus on both A. uva-ursi and P. abies show typical ectomycorrhizal features such as a hyphal mantle and a Hartig net. The main difference between the mycorrhizal symbioses with the different phytobionts is the occurrence of intracellular hyphae in the epidermal cells of A. uva-ursi. This emphasizes the importance of the plant partner for mycorrhizal anatomy. This is the first report of a previously considered host-specific ectomycorrhizal fungus in association with A. uva-ursi under natural conditions. The advantages of this loose specificity between the fungus and plant species is discussed.     

黄美乳菇（红菇目,红菇科）,中国首个乳菇属变红乳菇亚属中乳汁变黄的物种

红菇属变红乳菇亚属的乳汁常变为红色,变黄的乳汁较为少见。在中国中南部亚热带壳斗科林下发现了一个乳汁迅速变黄色的物种。这是首次在中国发现的变红乳菇亚属中乳汁变黄的物种,其独特的乳汁、褐色的菌盖、稀疏的菌褶和大的具极高翼状纹饰的孢子能将其与其他已知种区分开来,在此将其描述为新种,黄美乳菇L. mirus。本研究提供了该新种的DNA条形码ITS-LSU区域和形态特征描述,并将其与其他乳汁变黄的物种如马来西亚的L. flavorosescens和L. pallidior进行了对比。这一发现为证实中国乳菇属的亚热带-热带地区与亚洲热带地区的亲缘增加了新的证据。     

Microsatellite markers for the ectomycorrhizal basidiomycete Lactarius mammosus

We report the characterization of polymorphic microsatellite markers in the ectomycorrhizal fungus Lactarius mammosus Fr. Two enrichment protocols were used to isolate microsatellite loci and polymorphism was explored within 31 sporocarps originating from a forest site in northern Sweden. We found nine variable microsatellite loci with the number of alleles per locus varying between 2 and 5, and expected heterozygosities ranging from 0 to 0.84. These loci are available for the analysis of genetic structure and gene flow in L. mammosus populations.     

Occurrence of ectomycorrhizal fungi on the forefront of retreating Lyman Glacier (Washington,USA) in relation to time since deglaciation

Glacier forefronts provide a unique system for studying primary succession of plants and fungi. We constructed a chronosequence of ectomycorrhizal fungus occurrence on the forefront of Lyman Glacier in the North Cascades mountain range in Washington, USA. The plant communities established on non-vegetated substrate as patchily distributed plant individuals and developed towards complex vegetation with a variety of ectomycorrhizal hosts, including Salix commutata, S. phylicifolia, Abies lasiocarpa, Larix lyallii, Pinus contorta, Tsuga mertensiana and additional infrequent taxa. A most probable number assay of non-vegetated substrates over the chronosequence indicated that ectomycorrhizal propagules were few or absent in the non-vegetated areas adjacent to the glacier terminus but increased with time since deglaciation. Ectomycorrhizal fungus sporocarps occurred as soon as the first host plants of substantial size were present. However, none were observed with the most recently established hosts--small A. lasiocarpa seedlings. Only four species (Cortinarius decipiens, C. tenebricus, Inocybe lacera, and Laccaria cf. montana) occurred on substrate deglaciated for less than 40 years. Three of these species (C. tenebricus, I. lacera, and L. cf. montana) occurred along the chronosequence to the terminal moraine on substrate deglaciated for 70-100 years. An additional five species (one unidentified species each of Cortinarius and Lactarius, Cortinarius mutabilis, Lactarius uvidus var. montanus, and Suillus cavipes) occurred only on the oldest substrate. Our results support the current "early- and late-stage" model of ectomycorrhizal fungus succession in that additional species enter the community over time. However, we hypothesize that diversification of the mycorrhizal fungus community in this primary successional habitat resulted from an increasing diversity of host plants along with changing habitat attributes.     

Raman spectroscopic monitoring of Lactarius latex

Lactarius is a genus of Basidiomycotina with mainly agaricoid representatives, which are characterised by the excretion of a typical milky fluid. In particular, the colour, changes and taste of this latex-like milk are often used as a taxonomically important character. When it is exuded several chemical reactions occur. To date, NMR spectroscopy is generally used for chemical investigation of this latex. However, as a vibrational spectroscopic technique Raman spectroscopy has several advantageous properties for this type of research. The aim of this study is to investigate whether Raman spectroscopy can be used as an alternative analytical technique to monitor the chemical reactions in Lactarius latex. Therefore, this paper presents the first Raman spectra of Lactarius latex and provides an interpretation of the Raman bands that are present. L. lacunarum latex spectra are thoroughly investigated by 2D correlation analysis and are compared with latex spectra of other species (L. chrysorrheus, L. deterrimus, L. fluens, L. glyciosmus and L. salmonicolor).     

磷对外生菌根真菌松乳菇和双色蜡蘑草酸、氢离子和磷酸酶分泌的影响

在液体培养基中设置无磷、低磷、中磷和高磷四种磷浓度,离体培养松乳菇Lactarius deliciosus的3个株系Ld-01、Ld-02、Ld-03和双色蜡蘑Laccaria bicolor S238N,分别测定外生菌根真菌的生长量、草酸、氢离子和酸性磷酸酶分泌速率。结果表明,在中磷的条件下,外生菌根真菌的生长最好,无磷、低磷或高磷对它们的生长产生抑制作用,抑制程度因菌种(株)不同而异。草酸、氢离子和酸性磷酸酶的分泌速率顺序为:无磷(0gNaH2PO4/L)>低磷(0.229gNaH2PO4/L)>中磷(1.147gNaH2PO4/L)>高磷(5.735gNaH2PO4/L),表现出明显的种(株)间差异,看来外源磷的供应状况可能有调节外生菌根真菌活化土壤无机磷和有机磷的作用。在缺磷和低磷条件下,外生菌根真菌具有较强的活化作用,在足磷的条件下活化作用减小,由此有效地利用土壤中的磷。     

Intraspecific variability of Lactarius deliciosus isolates: colonization ability and survival after cold storage

Intraspecific variability in root colonization, extraradical growth pattern, and survival after cold storage of Lactarius deliciosus isolates was determined in pure culture conditions using Pinus pinaster as a host plant. The ectomycorrhizal ability of L. deliciosus at 30, 45, and 60 days from inoculation was highly variable among isolates and was negatively correlated to the age of the culture (time elapsed from isolation). The formation of rhizomorphs was related to colonization ability, but no relationship was found between colonization and formation of extraradical mycelium. The final colonization achieved at 60 days from inoculation was not related to the tree species under which the sporocarps were collected. However, isolates from sporocarps collected under P. pinaster colonized more rapidly the seedlings than those collected under other pine species. The climatic range of the sporocarps from which the isolates were obtained (maritime vs. continental) was not related to the formation of mycorrhizas at 60 days from inoculation. However, isolates from sporocarps collected from a maritime climate area colonized more rapidly the P. pinaster seedlings than those collected from a continental zone. Tolerance to cold water storage of L. deliciosus was also isolate dependent. Growth revival in agar was obtained from most of the isolates after 28 months of cold storage at 4°C, but only 10 out of 29 isolates showed unaffected growth. The ITS rDNA alignment of all the L. deliciosus isolates showed a low variability with identities over 99%. Most of the variation was detected in the ITS1 region and consisted in single nucleotide changes and/or punctual indel mutations. The number of base differences per sequence from averaging over all sequence pairs was 1.329, which is in the low range when compared with other ectomycorrhizal species. No ITS pattern due to geographical origin of the isolates could be discerned.     

磷对外生菌根真菌松乳菇和双色蜡蘑草酸、氢离子和磷酸酶分泌的影响

在液体培养基中设置无磷、低磷、中磷和高磷四种磷浓度,离体培养松乳菇Lactarius deliciosus的3个株系Ld-01、Ld-02、Ld-03和双色蜡蘑Laccaria bicolor S238N,分别测定外生菌根真菌的生长量、草酸、氢离子和酸性磷酸酶分泌速率。结果表明,在中磷的条件下,外生菌根真菌的生长最好,无磷、低磷或高磷对它们的生长产生抑制作用,抑制程度因菌种（株）不同而异。草酸、氢离子和酸性磷酸酶的分泌速率顺序为：无磷（0g NaH2PO4/L）> 低磷（0.229g NaH2PO4/L）     

Molecular identification of the edible ectomycorrhizal fungus Lactarius deliciosus in the symbiotic and extraradical mycelium stages

Specific rDNA ITS amplifications, microsatellite-primed PCR and ITS-SSCP analysis were applied to identify and characterize pre-selected isolates of the edible ectomycorrhizal fungus Lactarius deliciosus in different stages of the life cycle. Sampling was performed from pure cultures, mycorrhizas and soil from experimental plots established with nursery-inoculated pine seedlings. A newly-designed reverse primer (LDITS2R) combined with the universal forward ITS1 allowed to perform specific amplifications of L. deliciosus from all the samples. Microsatellite-primed PCR using the (GTG)5 oligonucleotide as a primer showed clear polymorphisms among the different L. deliciosus isolates. The patterns of mycorrhiza samples showed additional bands corresponding to the plant DNA. Single strand conformation polymorphism (SSCP) analysis of the specific rDNA ITS fragment amplified from 18 L. deliciosus isolates showed nine clearly different patterns. Mycorrhiza and soil samples showed coincident patterns with their respective fungal isolates. Specific rDNA ITS amplifications had not been previously used for SSCP analysis of ectomycorrhizas and extraradical mycelium. This relatively simple and inexpensive technique allows tracking L. deliciosus isolates in different stages of the fungus development. Specific ITS-SSCP analysis is promising in studies of the persistence of inoculated L. deliciosus isolates and their competitiveness with native ectomycorrhizal fungi, especially at the extraradical mycelium stage.     

Three new species of Lactarius (Russulaceae,Russulales) from Northeast China

Three new species of Lactarius are described from Northeast China, based on morphological comparisons and analyses on ITS nrDNA sequences. Samples of these species were mostly collected from deciduous or mixed forests with oaks. Lactarius albidocinereus, a member of L. subg. Plinthogalus is very similar to European L. azonites in the morphology and the sequence data. It differs from L. azonites by more ellipsoid spores with thinner ornamentation and shorter terminal cells in the pileipellis. Lactarius dilutisalmoneus belongs to L. sect. Zonarii of L. subg. Lactarius due to the pale salmoneus subzonate pileus with glabrous margin, unchanging latex and spore ornamentation composed of isolated elements. In comparison with its relatives, i.e. European L. zonarioides and North American L. olympianus, this new species has smaller spores with more prominent ornamentation. Lactarius olivaceorimosellus, a member of L. subg. Russularia, has areolate-rimulose pileus and lacks rosettes in the pileus and stipe cortex. Apart from the concentrically cracked pileus and absence of rosettes, the species can be easily distinguished by the olivaceo-brownish tinge of the pileus and spores with more dispersed elements of the ornamentation. Of the three species, at least L. albidocinereus represents a link with the Lactarius mycota of subtropical China.     

Small genets of Lactarius xanthogalactus, Russula cremoricolor and Amanita francheti in late-stage ectomycorrhizal successions

We determined the size of genets of late-stage ectomycorrhizal fungi in field sites in coastal Northern California. Basidiocarps were collected, mapped and subjected to genetic fingerprinting using amplified fragment length polymorphisms (AFLPs). The minimum size estimates for the largest genets of Amanita francheti, Lactarius xanthogalactus and Russula cremoricolor were 1.5, 9.3 and 1.1 m2, respectively. The molecular markers also showed that R. cremoricolor is dimorphic, with red- and white-capped morphotypes of this species forming a continuous population. Our results suggest that spore propagation plays a much more important role in the life history of the Russulaceae in undisturbed forest settings than previously recognized. Fungi appearing late in the succession sequence and systems without obvious disturbance therefore do not necessarily colonize primarily by mycelium.     

山东省的菌根真菌及分布

1842年Vittadini观察到树木小根可以从在其上面形成根套的真菌中获得营养。1885年Frank发展和完善了Vittadini 的观察,提出     

The ectomycorrhizal symbiosis between Lactarius deliciosus and Pinus sylvestris in forest soil samples: symbiotic efficiency and development on roots of a rDNA internal transcribed spacer-selected isolate of L. deliciosus

The effect on plant growth of pre-inoculation of Pinus sylvestris with the ectomycorrhizal (ECM) edible basidiomycete Lactarius deliciosus (isolate D45) under controlled conditions, and the development on roots of this basidiomycete, were investigated in gamma-irradiated and unsterilized containers containing different forest soil cores or a perlite-vermiculite mixture. Five months after planting, L. deliciosus mycorrhizal plants exhibited greater growth than the non-mycorrhizal ones in all soil types, i.e. up to a 325% increase in shoot height in the sterilized soils. The experiment demonstrated the dependency of P. sylvestris seedlings upon ECM symbiosis for their survival in gamma-irradiated, microbiologically disturbed soil samples. Furthermore, in two soils, the growth of L. deliciosus-inoculated seedlings was greater in the sterilized soil samples than in the non-sterilized ones, i.e. 46% and 132% increase in shoot height under sterilized soil conditions. In containers randomly sampled from each soil type, the degree of root colonization by the inoculated isolate, calculated as the number of mycorrhizal root tips divided by the total number of root tips x100, ranged from 80% to 35%. Within the short term, the inoculated isolate developed rapidly on roots, dominated, and hampered ectomycorrhiza formation by various unidentified (but not Lactarius) resident ECM fungi in unsterilized soil types. Results indicate that the ECM species L. deliciosus is worth investigating to ascertain if other isolates benefit pine growth like the isolate D45, and are therefore also attractive candidates for forestry applications in the Mediterranean area.