ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018634

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYSince the question of narrow as contrasted to broad species concepts and narrow versus broad generic concepts is important to present day attempts to classify Hymenomycetes into a natural system, the author discusses both in relation to his own experience in the group. Several points are emphasized:1)Those who work critically with significant numbers of species have arrived at species concepts of about the same“magnitude,”or, if very broad concepts are maintained the species is divided into subspecies with the latter corresponding to the narrow species of the other workers.2)It seems to the author, because of the mosaic pattern of speciation in most groups, that relationships can be more clearly expressed by broad generic concepts than by the narrow ones now being proposed by some investigators.3)The above conclusion is based in part on the fact that there are obvious parallelisms in hyphal characters just as there are in those involving gross morphology. The best solution will be reached when all the characters of species are taken into account to group them.4)It is shown that many of the hyphal characters emphasized today are not as clear and convincing as some investigators would lead us to think, and their value in arriving at concepts of relationship is limited.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018635

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYIt is proposed that the genusLamprodermabe recognized mainly on the basis that most of the capillitium arises from the apex of the columella. It is considered that the presence of a persistent peridium is too inconsistent to use as the major delimiting characteristic. Two new species are described. Their names and major characteristics are given below:Lamproderma biasperosporum, capillitium branching at the apex to form a weak, lax net, threads straight, becoming hyaline at the tips, sporangia widely scattered and less than 0.5 mm in diam, spores with clusters of larger, darker warts;Lamproderma acanthosporum, sporangia sessile, spores 18–20μin diam with spines reaching 2.0μin length. The speciesLamproderma fusiformeis transferred to the genusComatricha, and becomesC. fusiforme. Lamproderma fuscatumMeylan is regarded as a good species and is reported for the first time from the Western Hemisphere. A key to all the world species ofLamprodermais included; 18 species are recognized by the author.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018636

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYThe microcyclicCronartium paraguayenseSpeg. was found not to belong in the genusCronartium.It is redescribed and transferred toDidymopsoraasD. paraguayensis(Speg.) J. L. Cunn. A KOH treatment of the herbarium material restored it well enough to enable study of the ontogeny of the teliospores, including nuclear relationships. The 2-celled teliospores are formed initially in chains arising from a mycelium-lined cavity in the host leaf. Binucleate basal cells divide conjugately to form alternately spore initials and intercalary cells. The spore initials divide making the young spore 2-celled. The two nuclei in each cell fuse, the spore wall thickens, and usually the component cells of the mature teliospore separate, although in mass they adhere to make a hard hair-like column. The ontogeny of the teliospores is basically similar to the ontogeny of catenulate aeciospores of other rusts.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018637

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYThe influence of population size, method of isolation and time of sampling on the prevalent species composition in sample populations of soil microfungi inhabiting the maple-elm-ash floodplain forest was investigated. Populations were also isolated from the litter to assess their contribution to the prevalent forms appearing in the underlying mineralized soil. The data revealed that the prevalent species composition in 200-membered populations was very similar to that of 1,000-membered populations. Furthermore, the population pattern appeared to remain relatively stable over a 19-month period, during which time the community was subjected to annual inundation. The greatest number of prevalent forms was isolated from dilution plates, although several additional prevalent forms were isolated from soil plates and immersion tubes. It was concluded that microfungi inhabiting litter were unable to attain high frequencies in the populations found in the mineralized soil.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018638

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYFour-day cultures of nematophagous fungi that contained mycophagous nematodes exhibited little correlation between increased fungal growth and increased nematode-trapping effectiveness. Increased fungal growth did not appear to be affected by the assimilation of nematode protoplasm. Temperature and nematode presence appeared to be the two factors that affected fungal growth. Cultures that did not contain nematodes responded in a similar fashion to temperature. The presence of nematodes resulted in 5 C increase in optimum growth temperatures over control cultures, increased absolute areas of fast-growing species (Arthrobotrys oligospora, A. musiformis, andMonacrosporium bembicodes), and increased relative areas of slow-growing species (Arthrobotrys dactyloidesandMonacrosporium cionopagum).

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018639

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYPythium heterothallicumis described as a new species. The species designation“heterothallicum”was chosen to emphasize the absence of homothallic isolates, in contrast toP. sylvaticumin which isolates with varying degrees of homothallism occur.P. heterothallicumwill not mate with any of the tester strains ofP. sylvaticumfound to date. It differs morphologically fromP. sylvaticumin possessing a larger number of antheridial branches and antheridia. It also grows much slower at 25 C, averaging only 1.5 cm of radial growth in 24 hr in contrast toP. sylvaticumwhich averages 2.6 cm.P. heterothallicumwill not grow at 35 C whileP. sylvaticummakes slight growth.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018640

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYAn isolate ofClaviceps paspali, Ta-1, produced ergot alkaloids after total biomass formation was over (Pattern No. 1) when cultured on complex organic media favoring rapid growth rate (e.g.,k>3), and during biomass formation (Pattern No. 2) when cultured on sugar- or polyolammonium succinate media favoring low growth rate (e.g.,k<0.6). This is the first direct evidence that a given culture can produce ergot alkaloids by both patterns. Composition and concentration of the nutrients of the production medium appear to be the factors determining which pattern was followed.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018641

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYThis paper presents expanded descriptions and new illustrations for 29 of Burt's types. Eight of Burt's names are reduced to synonymy and one new combination is made.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018642

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

SUMMARYData are presented which show that selfing (or apogamy) sometimes takes place in common-mating type crosses as well as in individual clones of known mating types. These conclusions were arrived at through appropriate use of three kinds of genetic markers.

ISSN:0027-5514    

DOI:10.1080/00275514.1968.12018643

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor