摘要:

ABSTRACTA new family, Sigmoideomycetaceae, is proposed forSigmoideomyces, Thamnocephalis, and a new genusReticulocephalis.The family is characterized by sporophores having fertile heads composed of dichotomously branched, coiled hyphae in which the width of the coil is largest distally. Usually, each branch terminates in a sterile spine, which can either be free or adherent to other spines; modified spines may bear hyphal coils. All fruiting hyphae, including spines or modified spines, are irregularly septate at maturity. Cells formed at each branching point of a sporangiophore, except the final one or two, bear a pair of stalked fertile vesicles covered with pedicellate, unispored sporangiola.Reticulocephalis, Sigmoideomyces, andThamnocephalishave similarly constructed fertile heads but differ in the habit of the sporophore. InThamnocephalisthe fruiting structure is stalked and the fertile head is elevated well above the substratum, whereas inReticulocephalisandSigmoideomycesthe fruiting structure is sessile or procumbent. InReticulocephalisthe sterile spines have adherent tips and the sporangiola are smooth walled, whereas inSigmoideomycesthe sterile spines are free and the sporangiola have finely echinulate walls. Two new species are described:Reticulocephalis gyrosus, which produces coils of hyphae on the apices of modified sterile spines, andThamnocephalis sphaerosporawhich forms smooth-walled to faintly spinose sporangiola and spherical to obovoid fertile vesicles.Sigmoideomyces divaricatusis emended to indicate that the sterile spines are nearly evanescent, leaving behind only a wispy remnant of the wall, which is not due to filamentous bacteria as suggested by the original author. Sigmoideomycetaceae are hypothesized to be monophyletic.Reticulocephalis, Sigmoideomyces, andThamnocephalis, and all of their species, are monophyletic. All three genera are patristically equidistant from the hypothetical ancestor. OnlyCunninghamellais retained in Cunninghamellaceae. Keys to the genera and species are provided. A revised family description is presented for Cunninghamellaceae.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026188

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTThe new combinationValsonectria cinnamomiis proposed and the fungus is studied in culture. Ascospores germinated by forming yeast-like budding cells through fissures, eventually developing small colonies of hyaline conidia which germinated to form hyphae at the colony margins. Hyphae produced conidia holoblastically from numerous loci per cell. Some colonies formed thick, dark brown, mycelial threads composed of loose aggregates of hyphae in which the cells rounded up and disarticulated into arthrospore-like cells. Eventually, colonies produced stalk-like stremata which gave rise to the teleomorph at the apex. No conidiomata were formed.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026189

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTAn apothecial discomycete from diseased branches of Japanese red pine in Georgia was found to be conspecific withCenangium atropurpureum.After comparison of the Georgia material withCe. ferruginosum, the type species, it was concluded that on the basis of ectal excipular characteristics,Ce. atropurpureumis better accommodated inCrumenulopsis.This species differs from European species ofCrumenulopsisin the oval shape of the ascospore, presence of a gelatinous ascospore sheath, and possession of a diffusible purplish pigment in KOH. It differs from the Florida species,Cr. lacrimiformia, in the shape of the ascospore and ascospore sheath, larger size of the ascoma, presence of the purple pigment, and host species.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026190

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTHomokaryon-homokaryon and heterokaryon-homokaryon interactions of sibling strains of the ectomycorrhizal fungusPisolithus arhizuswere investigated. Pairings between sexually compatible homokaryons gave rise, almost always, to heterokaryotic mycelium in both of the progenitors, but in some cases heterokaryotic mycelium was present in only one of the progenitors. This unidirectional movement of nuclei and the speed of nuclear movement was followed in six representative pairings of homokaryons and complete heterokaryotization occurred rapidly, within 4 days, in one progenitor of one pairing. In heterokaryon-homokaryon pairings, heterokaryotization of the homokaryon was a consistent feature in all legitimate mating type pairings except in one case. Heterokaryotization did not occur in illegitimate pairings. The nuclear constitution of three analyzed heterokaryotized colonies was found to be a composite genotype containing one nucleus from the donor heterokaryon and one nucleus from the recipient homokaryon. This study is the first report of the homokaryon-homokaryon and homokaryon-heterokaryon nuclear interactions ofP. arhizus.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026191

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTThe sedge parasiteKriegeria eriophoriwas examined with light and electron microscopy to elucidate its basidial development and life history. Hyphae occur in xylem vessels in the leaf. Thin-walled, saccate probasidia form within the leaf and are the site of karyogamy and meiosis I through late prophase. They develop filaments that break through the probasidial wall and grow through the stomata to the underside of the leaf and there form metabasidia. Meiosis is completed in the metabasidia, which produce both ballistospores and yeast cells. Spores may reproduce asexually in the field and in culture by budding as a yeast with candelabra-like morphology, and this anamorph is named here asZymoxenogloea eriophori.Basidial development is compared to that of other heterobasidiomycetes and its phylogenetic significance is discussed.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026192

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTThree new species ofAmanitaincludingA. basiorubra, A. austroviridis, andA. luteivolvataare described from Western Australia. They are members of subgenusLepidellaand found as mycorrhizal associates ofEucalyptusin the southwestern forests of Western Australia.Amanita austroviridishas a restricted distribution but the other two species are widely distributed.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026193

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTSeveral Plasmids with different promoter sequences, all containing theHygBgene that confers resistance to the antibiotic hygromycin B, were evaluated for their ability to transformTrichoderma viridestrain T105-227 Nie-. Plasmid pH1B, which contains a promoter sequence fromCochliobolus heterostrophus, was found to give the largest number of putative transformants. Transformation ofT. harzianumstrains T12-2 His- and T95-1 Lys- was attempted, and the time at which transformed protoplasts were exposed to hygromycin B was found to be critical. If hygromycin B was added before protoplasts had regenerated for at least 6 h, no transformants were obtained. However, if regeneration proceeded for more than 12 h, many nontransformed protoplasts formed thalli. Putative transformants were heterokaryotic. Even if thalli were grown in the presence of hygromycin B, the number of transformed nuclei was low; only 0.5 to 0.8% of conidia from putative transformants were capable of producing thalli in the presence of hygromycin B. Subcultures derived from single hygromycin B-resistant conidia were stable. Southern analysis indicated that the plasmid was integrated into the genome in either tandem repeat pattern or was single copy insertion.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026194

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTSclerotium rolfsiiis a widespread sclerotial fungus that causes leafand stem blights of a large number of plants. Infrequently its teleomorph,Athelia rolfsii, has been found in nature or induced to form under laboratory conditions. Laboratory induction of the teleomorph of such isolates has often proven difficult or impossible. As a result there are numerous isolates ofS. rolfsiifor which the teleomorph stage is unknown or uncertain. We undertook a number of experiments on a large variety of isolates to test the impact of several environmental factors on teleomorph induction inS. rolfsii, and compared morphological features of each teleomorph induced to determine if they were all, in fact,Athelia rolfsii.A corn-leaf-culture method is recommended for rapid, dependable teleomorph production. We conclude that all isolates of the teleomorph stage we induced wereA. rolfsii.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026195

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTSixteen characteristic aromatic lichen products were identified in alga-free fungal cultures derived from single-spore isolates of four chemotypes of theRamalina siliquosaspecies complex. The chemistries of many cultures are more complex than those of natural thalli. The compounds identified include the majorβ-orcinol depsidones that characterize the chemotypes as well as biogenetically reasonable precursors not yet proved in natural thalli. Single-spore progeny from natural thalli can be assigned to chemotype without being lichenized with an alga. This result simplifies the use of secondary-product chemistry as a genetic marker to assess the limits of gene flow between chemotypes in natural populations.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026196

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

ABSTRACTPhoma sorghinais a newly described leaf spot pathogen on pokeweed. The fungus produced six Phytotoxins in liquid culture which were isolated and structurally identified as 6-methylsalicylic acid, epoxydon, desoxyepoxydon, phyllostine, 2,3′-dihydroxy-4-methoxy-5′,6-dimethyl diphenylether, and epoxydon 6-methylsalicylate ester. The cell-free culture filtrate and all six toxins caused necrosis when spotted on pokeweed leaves and eight other weed species thus all six toxins were nonspecific Phytotoxins. Epoxydon, desoxyepoxydon and the diphenylether showed strong antimicrobial properties against all bacteria and fungi tested. 6-Methylsalicylic acid, epoxydon and the diphenylether also inhibited sorghum root growth.

ISSN:0027-5514    

DOI:10.1080/00275514.1992.12026197

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor