Fruiting body formation of the nivicolous myxomycete Badhamia alpina in moist chamber culture

The plasmodium of Badhamia alpina thrived at lower temperatures (4 °C), and formed fruiting bodies at 8 °C. The yellow sclerotium and plasmodium were found inside a hollow, dead herbaceous stem under melting snow in Apr, and was cultured in moist chambers at 4 °C. The plasmodium did not form fruiting bodies for 6 wk at 4 °C. Sporulation was observed after the incubation temperatures rose to 8 °C. Sporulation occurred in the morning and cell cleavage at 11 a.m. The order of spore wall formation was observed by TEM for 12 h. The outer spore wall ornamentation was formed first followed by internal wall layers. Round electron transparent object was observed in the capillitium and peridium during the latter part of sporulation.     

Fungus fruit body lytic enzyme from a myxomycete,Badhamia utricularis

Chitinase,β-1,3-glucanase, cellulase, xylanase and protease activity were detected in a crude enzyme preparation obtained from a slime mold (Badhamia utricularis) which was grown on autoclaved mycelia ofPholiota nameko in a petri dish. The optimal pH of the enzyme preparation for lytic activity against fruit bodies ofLentinus edodes was 4.0, and those ofβ-1,3-glucanase and cellulase were the same. On the other hand, chitinase and protease showed optimal activity at pH 5.0 and 8.0, respectively. The lytic activity was stable below 40°C but completely inactivated at 70°C, and was most stable at pH 5.0. The studies of the optimal pH, thermal stability, and pH stability, and isoelectric focusing analysis of the enzyme preparation suggest that chitinase,β-1,3-glucanase and cellulase activities may be responsible for lysis of fruit bodies of some mushrooms. The crude enzyme preparation from the slime mold lysed fruit bodies of several mushrooms more efficiently than did commercial lytic enzymes preparations (Driselase and Usukizyme).     

细钙丝菌子实体发育过程中表面亚显微形态特征和化学元素变化研究

利用扫描电子显微镜和能量色散X射线分析技术对细钙丝菌Badhamia gracilis子实体发育过程中原生质团和子实体一些结构的外表面亚显微形态特征与化学元素变化过程进行了研究。结果显示:原生质团表面为膜质、具有乳突的结构;囊被表面经乳突状结构发育为光滑且波浪状的膜质结构,表面分布着带弯型膜质通道的石灰质颗粒分泌口(0.6–0.8μm);柄表面经乳突状结构发育为膜质、具有纵褶的结构,内部包含石灰质颗粒;孢丝表面为粗糙的膜质,内部包含石灰质颗粒;孢子为表面具有不规则疣和脊的膜质结构。各发育阶段原生质团、囊被、柄、孢丝及孢子表面具有特定的化学元素种类,亚显微形态特征相同的结构表面部分化学元素相对含量更为相近。     

生物系统学与自然保护

生物系统学的知识是自然监测和保护的基础。随着自然保护观念由强调重点物种或代表性生态系统保护转向强调保护地球上生物多样性,生物系统学将在自然保护中发挥更大的作用。     

Biosystematics of Hordeum bulbosum L.

Hordeum bulbosum L. is found in a diploid (2n = 14) and a tetraploid form (2n = 28). Of the 99 collections examined cytologically, 21 were diploid, 77 tetraploid and one triploid. The diploids were found in the western Mediterranean area to West Greece, tetraploids from West Greece eastwards to Afghanistan. Analysis of herbarium material and extensive cultivated material showed that the two cytotypes could not be distinguished morphologically. Intracytotype crosses were successful in the different provenance combinations, except in a few cases, where individual parental genotypes caused a low crossability. Intercytotype hybrids were rather difficult to obtain. In the light of the results a taxonomic subdivision of the species is not recommended. A problem in connection with the Linnaean type specimen is discussed.     

草生发网菌Stemonitis herbatica生活史的研究

本文研究了草生发网菌Stemonitis herbatica从孢子萌发-原质团形成-幼子实体-成熟子实体的个体发育完整过程。结果表明,草生发网菌孢子萌发类型为孔出式;原质团类型为隐型,子实体形态建成前形成淡黄色的珊瑚状原质团,需足够的光照后才能形成子实体;子实体的形成过程通常在6–7h内完成。     

Sedimentation velocity of myxomycete spores

Sedimentation velocities were measured for seven myxomycete species and one fungus. Values for these first measurements for Myxomycetes were fitted with the formula of Stoke’s law for the terminal velocity of small spherical bodies in air. The obtained correlation coefficient of R=0.939 indicates that sedimentation velocities of myxomycete spores follow Stoke’s law well. With spore density as a parameter, the fit estimated a mean density of 0.74 g/cm³ for air-dried spores. The importance of the stalked spore case as well as the spore diameter for dispersal abilities of Myxomycetes is discussed.     

Methionine metabolism of the myxomycete Physarum polycephalum

Daniel, John W. (University of Wisconsin, Madison), and Karlee Babcock. Methionine metabolism of the myxomycete Physarum polycephalum. J. Bacteriol. 92:1028-1035. 1966.-Previous studies have shown that Physarum polycephalum requires exogenous methionine for growth, but not cysteine, folic acid, or vitamin B(12). Methionine can also serve as the sole source of sulfur for all cellular requirements, without limiting the growth rate. S-methyl-l-cysteine, 2-hydroxy-4-methiol butyric acid, S-adenosyl-l-methionine, and methionine peptides were the only compounds supporting growth, when substituted for methionine. Other methionine analogues, methyl donors in combination with homocysteine, and intermediates of the cystathionine pathway were not active. Ethionine and S-ethyl cysteine were good methionine antagonists. This myxomycete is apparently unable to synthesize the methyl or S-methyl group, although it still appears able to transmethylate, at least from S-methyl cysteine, and probably from S-adenosyl methionine, which can also serve as a source of adenine.     

Plasmodial ultrastructure of the myxomycete Physarum polycephalum

When plasmodia of P. polyeephalutu are fixed simultaneously with osmium tetroxide and glutaraldchyde, the cytoplasm is so preserved that a system of microchannels, resembling pinocytosis channels, and numerous discrete vacuoles can be observed. With either fixative alone, the cytoplasm appears to contain large irregular vacuoles or a vacuolar continuum. The microehannels, approximately l µ in diameter, arising as invaginations of the plasma membrane are each surrounded by a sheath of thin filaments which in areas of invagination at the plasmodial surface seems to merge with a well-defined cortex underlying the plasma membrane. Coating the plasma membrane is a structured slime layer continuous with the microchannel contents. The location and structure of the microchannel-cortex system strongly suggests it as the site for localization of contractile function implicated in cyclosis and motility. Mitochondrial structures of special interest are also described.     

Biosystematics and diversity amongst novel carboxydotrophic actinomycetes

Fifty-four carboxydotrophic actinomycetes isolated from soils and composts were compared through 119 unit characters with representative mesophilic and thermophilic streptomycetes. The data were examined using the Jaccard, pattern and simple matching coefficients and clustering achieved using the unweighted pair group method with arithmetic averages algorithm. Acceptable cophenetic correlation and test error values allowed confidence to be placed in the resultant numerical taxonomies. The carboxydotrophic actinomycetes, which were distinct from cluster-groups corresponding to the mesophilic and thermophilic streptomycetes, formed two major cluster-groups the members of which were examined for the presence of diagnostic chemical markers. All but two of the carboxydotrophic actinomycetes had a profile of chemical properties consistent with their assignment to the genusStreptomyces. Quantitative fatty acid data were examined using the SIMCA package and the two statistically significant groups obtained corresponded with the cluster-groups circumscribed in the numerical phenetic analysis. Members of the two groups were also distinguished on the basis of their phospholipid composition. The two strains that containedmeso- as opposed to LL-diaminopimelic acid in their peptidoglycan also showed a distinct chemotaxonomic profile. It was concluded that the carboxydotrophic actinomycetes form a novel and taxonomically diverse group.     

Biosystematics of the genus Pinus, subsection contortae

Gene frequency data from 42 isoenzyme loci were used to assess the phylogeny of taxa in the genus Pinus, subsection Contortae. The classification inferred from a phenogram based on Nei's genetic distance measure (D_N) was generally in good agreement with the current taxonomic treatment of the subsection. Pinus contorta appears to most closely resemble the ancestral taxon from which all other taxa in the subsection are derived. An alternative classification based upon Mahalonobis squared distances (D_R) obtained from seed and cone measurements differed from the isoenzyme treatment by placing P. contorta subsp. murrayana in close association with P. virginiana.