摘要:

SUMMARYThe synthetic auxinlike postemergent herbicides 2,4-D, 2,4,5-T, 2,4,5-TP, dicamba, and MCPP were examined for their influence on conidial germination, germ-tube growth, primary branching of germ tubes, and conidial production ofDrechslera sorokinianaat molar concentrations of 10-12to 10-3. All herbicides of the 10-3M concentration prohibited conidial germination and caused visible plasmolysis of conidium cells. Germination of conidia was not affected by any herbicides at concentrations of 10-12to 10-4M. Germ-tube growth and primary branching of germ tubes were stimulated by most herbicides at concentrations of 10-12to 10-4M; some nonsignificant inhibition of these structures occurred in response to 2,4,5-TP and MCPP. Mycelial growth was stimulated by most herbicides at concentrations of 10-12to 10-4M; significant increases within this concentration range, however, differed with specific herbicides. Conidial production was inhibited by 2,4,5-T and MCPP at all concentrations; 2,4,5-TP and dicamba caused significant increases in conidial production at lower concentrations and a significant decrease at higher concentrations. Only 2,4-D increased conidial production at higher concentrations. The results of the investigation indicate that germ-tube growth is most dramatically stimulated by the herbicides examined and that vegetative growth (germ tubes, branching, mycelium) ofD. sorokinianashows a greater stimulatory response to very low concentrations of the herbicides. The study shows also that the herbicides at their various concentrations may have opposite effects on growth ofD. sorokiniana, depending on the stage of growth of the organism.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020167

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYComplete descriptions ofAmanita ocreataandA. phalloidesare given.Amanita ocreatais considered a distinct species and reported as a dangerously poisonous mushroom containing at least two amatoxins, alpha- and beta-amanitin.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020168

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYThe perfect state ofHelminthosporium coicis, causing leaf-blight disease ofCoixspecies, was produced on Sachs agar medium with rice straw by the same method described in previous papers on perfect state formation ofH. orysaeandCochliobolus miyabeanus.Morphologically, the perfect state is somewhat different fromCochliobolus, especially in the existence of basal columnar stromata and of ascospore arrangement with parallel to loose coiling in the ascus. Thus a new genus,Pseudocochliobolus, is described.Pseudocochliobolus nisikadoiis designated as type species of the new genus.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020169

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYPinus resinosaleaf litter with associated attached fungi collected from a coal strip-mining area in Perry County, Ohio was studied using atomic absorption spectrophotometry, scanning electron microscopy and X-ray emission microanalysis. Six-mo-old leaf litter accumulated Ca to more than three times the amount observed for living leaves. Other elements (P, Si, Cu, Zn, Fe) also appeared to accumulate inPinus resinosaleaf litter after 6-mo decomposition time. X-ray emission spectra and X-ray maps collected for leaves and fungi revealed a detectable partitioning of Ca and Fe in fungi, suggesting that fungi are partly responsible for regulating cycling patterns for these elements inPinusleaf litter. Partitioning of P, K, Si and Mn was not observed. These results are discussed in relation to current biological and physico-chemical models of element cycling regulatory mechanisms.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020170

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYThe essential oil ofCeratocystis virescenswas analyzed by means of gas and thin-layer chromatography, infrared spectrometry, mass spectrometry and chemical means. The oil fromC. virescenswas compared for chemotaxonomic purposes with that ofC. variospora.The major constituents in the oil ofC. virescenswere: 6-methyl-5-hepten-2-ol acetate, linalool and geranyl acetate. One cyclic terpene, a-terpineol, was isolated.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020171

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYGermination ofClaviceps paspalisclerotia occurred over a wide range of storage and incubation temperatures. Cold, moist storage conditions greatly enhanced germination but were not obligatory. Highest percentage germination and most rapid germination occurred after storage in moist sand at 5 and 10 C for 2 mo followed by incubation at 20 C for 41–44 da. Preconditioning periods at 20 and 25 C, incubation at 30 C, and dry storage of sclerotia were not conducive to germination.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020172

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYClaviceps purpureasclerotia did not survive longer than 6 mo regardless of the time of year sclerotia were placed outdoors in soil in Georgia. Sclerotia were rapidly deteriorated by soil microorganisms and damaged by plant roots, mites and insects.Claviceps paspalisclerotia survived up to 12–14 mo after placement in soil in October. Sclerotia placed in soil at other times of the year survived for shorter periods. Optimal sclerotial germination occurred 6–9 mo (April-July) after placement in the field on 1 November. The germination period corresponds to the time whenPaspalumspp. flower and when ergot is first seen in the field.Claviceps paspalisclerotia also were deteriorated by soil fungi and bacteria but 45–80% of the sclerotia germinated at optimal conditions. Lack of Sclerotium survival is responsible for the infrequent occurrence ofClaviceps purpureaupon small grains and grasses in the southeastern USA. Sclerotia ofC. paspaliprovide ascospore inoculum throughout the long flowering period ofPaspalumspp. but it is unlikely that sclerotia survive two seasons to produce ascospores.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020173

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYOf 10 isolates ofCeratocystis ulmicollected in September, 1970, from eight trees ofUlmusXhollandicacl.‘Belgica’and two trees ofU.Xhollandicacl.‘Commelin,’seven were of compatibility type B and three, type A. Peeled, split, autoclaved elm twigs, dipped for 10 sec into a 3-da-old liquid shake-culture (Tchernoff medium) of a B isolate and, 3 da later, into a similar culture of an A, were compared in December, 1970, with similar twigs dipped first into A and 3 da later into B. Abundant, fertile perithecia formed in all but seven of the 42 possible combinations: an A isolate from Doorwerth, Netherlands, formed perithecia with each of the seven B isolatesonlyif it was thesecondinoculum. It thus acted as a male: able to serve as effector but not as receptor. These tests were made with 3-mo-old isolates. Reisolation from the same branch of the original tree in April, 1971, again yielded type A, but hermaphroditic rather than male. Passage of the male culture through elms yielded symptoms typical of Dutch elm disease but did not change its unisexual nature. Of two aggressive cultures received from England (both compatibility type B), one reacted as hermaphrodite and the other as male in more limited tests.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020174

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYA previously described numerical taxonomy technique is used to compare the subsectionFloccipedes(in current taxonomy classified underHydropusorMycena, sect.Floccipedes) with the genusHydropus(without subsectionFloccipedes) andGerronemasubgenusGerronema.The technique was developed for assigning genera to families, and there are some differences, which are noted, when it is applied to this lower level. Further comments are made on the general method, including response to discussions of the method by a Swiss mycologist and an American statistician. The taxonomic result of our study confirms that subsectionFloccipedesshould be attached toHydropusrather thanGerronema.

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020175

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor

摘要:

SUMMARYThe roots of poinsettia (Euphorbia pulcherrima) cuttings became mycorrhizal when inoculated withGigaspora margarita.Maximum endomycorrhizal formation occurred following application of azygospores to both the rooting medium in the mist bed and, subsequently, to rooted cuttings at transplant. Cuttings inoculated in the mist bed or at transplant only, however, developed fewer mycorrhizae. Application of 125 ppm N-P-K per potted plant weekly favored mycorrhizal formation but there was no associated plant growth stimulation. Increasing N-P-K fertility to 250 ppm resulted in a mycorrhiza-induced growth response, but the plants eventually became chlorotic. Application of 125 ppm or 250 ppm N-P-K twice weekly significantly improved plant growth and appearance. At the lower rate, mycorrhizal synthesis was repressed, occurring only as scattered hyphae in the roots, and at the higher rate mycorrhizal synthesis was completely inhibited.Gigaspora margarita, in conjunction with Rootone, stimulated rooting of cuttings in the mist bed by markedly increasing the number and weight of roots over cuttings treated with Rootone alone. The mycorrhizal cuttings withstood transplant shock under high temperatures and low moisture conditions better than nonmycorrhizal cuttings. Thus, endomycorrhizal plants grew better than nonsymbiotic plants under conditions of low fertility and moisture stress, but the relationship appeared to be of minimal importance under cultural conditions favorable for the plant

ISSN:0027-5514    

DOI:10.1080/00275514.1977.12020176

出版商:Taylor&Francis    

年代:1977

数据来源: Taylor