Molecular phylogeny of Russulaceae (Basidiomycetes; Russulales) inferred from the nucleotide sequences of nuclear large subunit rDNA

Phylogenetic relationships of the genera Russula and Lactarius were investigated using sequence data from the nuclear-encoded large subunit ribosomal DNA (LSU rDNA). Ninety-five sequences belonging to the genera Russula and Lactarius, including 31 sequences from the databases, were used in this study. Analysis of the LSU rDNA region indicated that Russulaceae was divided into six groups (group A–F) in the neighbor-joining (NJ) tree. Lactarius consisted of one large clade (group A). Therefore, this genus was found to be monophyletic. However, the monophyly of genus Russula remained unclear. The genus Russula consisted of five groups in the NJ tree. Group B includes sects. Plorantes and Archaeinae (Heim), and group C includes sects. Delicoarchaeae and Russula in the NJ tree. Neither of the two groups formed a single clade in the most parsimonius (MP) tree. Group D includes many taxa having colored spore prints and amyloid in suprahilar plage of spores in sect. Russula and sect. Rigidae. Group E consists of only sect. Compactae and is further divided into three subclades, represented by R. densifolia, R. nigricans, and R. subnigricans, respectively. Group F contains sects. Rigidae, Ingratae, and Pelliculariae. Sect. Compactae and sect. Plorantes should not be as closely related as previously supposed. Russula earlei may be placed in sect. Archaeinae Heim. Russula flavida (subsect. Amoeninae) is placed in sect. Russula with R. aurea with a high bootstrap value (99%). The nuclear LSU rDNA region is a useful tool in recognization of species of Russulaceae and may provide information concerning phylogenetic relationships between the genera Russula and Lactarius.     

实验培养红菇对肠道致病菌的抑菌活性研究

研究实验条件下培养红菇菌丝和发酵液对几种肠道致病菌的抑菌活性。结果发现其对大肠埃希菌具有特异性抑制,对其他菌的抑制较弱。初步确定了最小抑菌活性,认为红菇多糖具有一定的抑菌潜力。     

亚稀褶黑菇和稀褶黑菇的ITS序列分析

对亚稀褶黑菇和稀褶黑菇的ITS全序列进行了测定和比较,首次报道了亚稀褶黑菇的ITS1和5.8S区域.在ITS区域中,不同采集地的亚稀褶黑菇与稀褶黑菇的5.8S rDNA具有100%的同源性,而两侧ITS之间表现出种内和种间的多态性,种内的差异均不超过5%,种间的差异达10%左右.ITS序列分析方法可以作为两者的鉴定方法.     

鳞盖红菇中一个新的倍半萜类化合物

从鳞盖红菇（Russula lepida Fr.）的氯仿／甲醇（1：1）部分分离得到一新化合物rulepidol(1),其结构经现代波谱技术鉴定为一aristolane型倍半萜。     

亚稀褶黑菇菌丝体最适培养基的正交试验研究

以四因素三水平的正交试验设计培养条件,pH5．6,26．2℃,45d,对亚稀褶黑菇茵丝体进行固体培养。通过对菌丝体直径的测定及分析,得到该菌种生长最适培养基配方为：(NH4)2HPO4 1g／1000mL,甘露糖15g/1000mh,KH2PO4,0．5g／1000mL;维生素B1 100μg/1000mL,并证明氮源为其生长的最重要营养因素。     

亚稀褶黑菇提取液诱导小白鼠肝肾细胞凋亡

采用琼脂糖凝胶电泳技术研究亚稀褶黑菇提取液诱导小打手势习肝肾细胞凋亡。结果显示,小白鼠亚稀褶黑菇抽提液中毒后,肝肾细胞DNA经琼脂糖凝胶电泳出现180－200bp整数倍的DNA梯形带,19.0-28.5g/L范围内,亚稀褶黑菇提取液诱导肝肾细胞凋亡表现出和剂量依赖性,结果表明,亚稀褶黑菇提取液能诱导小白鼠肝肾细胞凋亡。亚稀褶黑菇提取液诱导肝肾细胞凋亡是亚稀褶黑菇中毒后机体病变死亡的重要表现形式之一。     

亚稀褶黑菇中毒的临床表现和中毒机理探讨

本文通过对湖南省茶陵县亚稀褶黑菇中毒事件的调查,获得了尽的临床资料,并通过分析中毒病人的临床表现,首次探讨了亚稀褶黑菇的中毒机理, 结果表明,亚稀褶黑姑毒素作为一种外界信号分子与细胞膜受体结合,引起细胞内Ｃa^2 浓度上升,通过一系列生理生化反应过程,导致细胞死亡。     

A polymorphic repetitive-sequence PR1 family evidence for meiotic instability

When EcoRI digests of mouse genomic DNA were subjected to Southern blot analysis with the polymorphic repetitive sequence PR1 as a probe, one satellite-like band of 3.5 × 10³ base-pairs, designated as PR1 family B, was detected in BALB/c-strain mice, but not in the DDD/1- or MOA-strain mice. Analysis of recombinant phage clones revealed that the repeating unit of the PR1 family B was 13.5 × 10³ base-pairs long. This family consisted of a tandem array of repeating units and occupied as much as 2% of one BALB/c chromosome. Since the BALB/c-specific PR1 family B is not present in DDD/1 or MOA mice, the unpaired portion of the BALB/c chromosome may be looped out in a synaptonemal complex during meiosis in F₁ hybrids of the BALB/c strain with DDD/1 or MOA. To determine the fate of this extra DNA, we examined the genotypes of the F₁ hybrid mice and of the segregating populations. Although the PR1 patterns of F₁ and most N₂ mice are consistent with typical Mendelian inheritance, some N₂ progeny showed an abnormal 3.5 × 10³ base-pair band of unexpectedly reduced intensity. This indicated that the extra DNA of PR1 family B occasionally underwent recombination during meiosis in F₁ mice, resulting in its apparent excision. Examination of PstI digests supported this interpretation.