摘要:

ABSTRACTEjectosporus magnusbelongs to a new monotypic genus of Harpellales (Trichomycetes) found in the hindgut ofAllocapniaspp. nymphs (Plecoptera, Capniidae). The mature sporangiospore is forcefully ejected from the trichospore, a monosporous sporangium, while the sporangial wall remains attached to the generative cell. Trichospores apparently do not break away from the thallus as in most other genera of Harpellales. No trichospore appendages were observed. Another new hindgut species fromAllocapniaspp. nymphs,Paramoebidium corpulentum(Amoebidiales), is also described. The first axenic isolations ofSimuliomyces spica(Harpellales) from these stonefly hosts are reported.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026027

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTNucleotide sequences from a highly variable region of large subunit (25–28S) rRNA (D2 region, ca. 220 nucleotides) were determined for seven strains ofG. pulicarisand also for two strains each of threeG. fujikuroivarieties in order to assess the amount of within species or within variety sequence variation and to determine whether sequences of the varieties would be different in this rRNA region.One variable nucleotide position was found among theG. pulicarisstrains; all other readable bases were the same. No sequence differences were found among strains of eachG. fujikuroivariety. TwoG. fujikuroivarieties (intermediumandfujikuroi) had the same sequence and the third variety(moniliformis)differed from them at two nucleotide positions.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026028

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTCochlonema odontosperma, a zoopagalean fungus endoparasitic in terricolous amoebae, was examined using ultrathin sections. Conspicuous cellular components in the young thallus were many nuclei (ca1μm in diam), electron-dense vesicles (ca0.5μm) and small vacuoles (0.2-1.0μm). In older thalli there was usually one or more large vacuoles and a number of small vacuoles. Both the large and small vacuoles were often connected by a number of electron-dense vesicles. With vacuole expansion, the protoplasm migrated into the conidiogenous and zygosporangial hyphae outside the thallus.The conidia contained one or more nuclei and several vesicles (ca0.3μm). The latter tended to accumulate beneath the conidial cell wall at protuberances which appeared as bumps on the conidia under the light microscope.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026029

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTDifferent forms of vesicular-arbuscular mycorrhizal fungal inoculum are found in soil patches with differing histories. These inoculum types include spores, infected root fragments, and extramatrical hyphae. Utilizing root observation chambers, detailed observations were made of the growth dynamics of mycorrhizal hyphae from inoculum sources to roots and the subsequent radiation out from individual colonized root segments. There were several types of hyphal architecture classified by whether the external hyphae were entering (infecting) a plant root or developing from the root surface and growing out into the soil matrix. Morphologically, individual hyphal filaments within all architectural types looked quite similar and clear architectural differences could only be identified when distinct sets of interconnected hyphal filaments were studied. The primary hyphal architectural types observed in the soil were classified as runner hyphae, hyphal bridges, absorptive hyphal networks, germ tubes, and infection networks produced by spores and root fragments. The specialized hyphal architectures of these fungal endophytes appear to be linked to the unique function of each hyphal type. Runner hyphae and infection networks from either spores or root fragments were observed to be capable of infecting new root segments. Absorptive hyphal networks were never observed to act as units of infection and were classified as structures primarily involved in the acquisition of soil resources. This high degree of specialization may help explain why vesicular-arbuscular mycorrhizal fungi are so efficient in their beneficial role of nutrient and water transport to the host plant.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026030

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTHalophytophthora kandeliae, a new marine species was isolated from fallen, yellow leaves of mangrove,Kandelia candel.It is distinguished from other species ofHalophytophthoraprimarily by its regularly obovate to turbinate sporangia. A key to the species ofHalophytophthorais also provided.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026031

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTEvolutionary relationships ofLentinusto the Tricholomataceae and Polyporaceae were studied using restriction analysis of nuclear-encoded ribosomal RNA genes (rDNA). Five species ofLentinus, three species in the Polyporaceae and two species in the Tricholomataceae were examined. Ribosomal DNA phenotypes were determined by restriction endonuclease digestion of enzymatically amplified rDNA (PCR fingerprinting). This method generates restriction fragment length polymorphism data without Southern blotting or autoradiography. With five different four-base restriction enzymes, one hundred and one unique restriction fragments were resolved. Among the 16 individuals studied, there were twelve different rDNA types. A similarity matrix based on presence or absence of comigrating restriction fragments was analyzed with UPGMA, complete and single-linkage analysis (using the NTSYS computer package), and Fitch-Margoliash and KITSCH analysis (using the PHYLIP computer package). Results of all analytical approaches were highly consistent and strongly suggest thatLentinus tigrinusis more closely related to the Polyporaceae than to the Tricholomataceae. Morphological characters (dimitic hyphae and hyphal pegs) also support this hypothesis. The other species ofLentinusappear to be intermediate between the Polyporaceae and Tricholomataceae and could not be clearly assigned to either family. The results also suggest thatLentinusis paraphyletic and, therefore, that lamellae have arisen repeatedly by convergent evolution.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026032

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTBasidiospores of fiveformae specialesofCronartium quercuumcan be readily separated into three distinct groups on the basis of color, length-to-width ratios, and size. The Japanese f. sp.densifloraehas globose to subglobose hyaline basidiospores. All four Americanformae specialeshave yellow-orange ellipsoid basidiospores with special formsechinataeandfusiformehaving length-to-width ratios of 1.3-1.4, whereas f. spp.virginianaeandbanksianaehave length-to-width ratios of 1.6-1.8. Basidiospores from isolates of three American special forms from widely separated geographic locations had similar shapes and sizes. Urediniospores of the four Americanformae specialesdo not vary in size or ornamentation.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026033

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTComparative isozyme analyses were performed on three species ofTremellato test their utility as a taxonomic tool and to genetically characterize these fungi. A total of 28 enzymes were surveyed from 86 basidiocarps ofT. moriformis, 11 basidiocarps ofT. indecorata, and 35 basidiocarps ofT. globospora.Twenty-one enzymes (22 loci) retained sufficient activity to be useful in this survey. Twelve enzymes were monomorphic among all three species yet retained species-specific mobilities; of these only 1-glycerophosphate dehydrogenase showed too little interspecies variation to be useful taxonomically. Nine polymorphic enzymes were identified (10 loci); of these only the pair of electromorphs of alcohol dehydrogenase and one electromorph of isocitric dehydrogenase were common to two species.The predominance of monomorphic enzymes and the clear distinction of electromorphs between species suggests isozyme analysis is well suited as a taxonomic tool within the genus.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026034

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTThe effect of environmental and cultural conditions on the growth and competition between shiitake mushroom mycelium and the competitorTrichoderma harzianumwas investigated.T. harzianumhad higher growth rates and temperature optimum and tolerated more variable pH.T. harzianumgrew at lower water potentials than didL. edodes.No difference was detected in growth or dual challenge culture under moderate levels of CO2, pre-exposure toT. harzianum, low levels of sucrose and KCl supplementation, and substrate moisture contents between 39% and 70%. Conditions that favored the growth ofL. edodesoverT. harzianumwere moisture contents above 35%, 2 or 4 h of autoclaving the substrate, the use of oak sawdust in place of a hickory-ash mixture, the use of weathered sawdust, supplementation with 4% gypsum, low levels of bran supplementation, partial replacement of organic nitrogen sources with urea, and low levels of straw supplementation. Shiitake strain 465 exceeded strain 305 in its ability to compete withTrichodermawhen grown on a 9% bran supplemented medium. A simple technique was developed forin situobservations of growth and fungal interactions.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026035

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

ABSTRACTFrom montaneQuercus humboldtiiforests in Colombia, three new taxa ofPhaeocollybia(Agaricales, Cortinariaceae) are described and illustrated, viz.P. ambigua, P. caudata, andP. singularis. Phaeocollybia oligoporpaandP. quercetorum, both originally recorded from oak forests of Costa Rica, represent first reports for the Colombian mycota.

ISSN:0027-5514    

DOI:10.1080/00275514.1991.12026036

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor