摘要:

A new species ofFilobasidiellaKwon-Chung is described and illustrated. This species,F. arachnophila, was isolated from a dead spider and appears to be nonpathogenic. It differs from previously described species in being homothallic and in lacking a yeast-like phase of growth.

ISSN:0008-4026    

DOI:10.1139/b78-220

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

In a field experiment the wheat cultivars Glenwari, Exchange, Thatcher, Warigo, Idaed 59, and Hopps were assessed as having slow rusting abilities when artificially inoculated with a mixture of 22 physiologic races of stem rust. Resistance that resulted in slow rusting was demonstrated in growth cabinets with adult plants of these six cultivars after standardized inoculation with three stem rust races followed by uniform incubation and growth conditions. The investigation revealed that the following different kinds of resistance were involved: (1) 'specific' resistance effective against race C17 was observed in tests with seedlings and adult plants of Thatcher, Hopps, and Idaed 59; (2) low receptivity was observed in tests with adult plants of Glenwari, Warigo. Hopps, and Idaed 59; and (3) low urediospore production per pustule was evident in tests of the cultivar Exchange. The resistance of the cultivar Thatcher appeared complex, involving slow and nonuniform pustule development.Resistance expressed as low receptivity and low urediospore productivity varied in effectiveness against different physiologic races. In many instances significant interactions occurred between cultivars and races. Temperature changes appeared to affect the expression of resistance in many race–cultivar combinations. Thus, this type of resistance does not fit the definition of horizontal resistance proposed by van der Plank. Nevertheless, field investigations indicate that the resistance is effective against many rust races and could be potentially valuable in breeding programs.

ISSN:0008-4026    

DOI:10.1139/b78-221

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Studies were carried out on the ability ofTalaromyces emersoniiStolk to produce extracellular lipase in stationary liquid medium under various conditions. The best temperatures for lipase synthesis and activity were 40–45 °C, and at all the temperatures (37–55 °C) tested for lipase production, maximum enzyme was produced 8 days after incubation. Lipase synthesis was induced when various carbohydrates were used as carbon sources both in the presence and absence of yeast extract. The significance of lipase production in relation to the natural habitat is discussed.

ISSN:0008-4026    

DOI:10.1139/b78-222

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Floral development inCaryopteris×clandonensisA. Simmonds (C. incana(Houtt.) Miq. ×C. mongholicaBunge) from cyme initiation through to anthesis is described, with emphasis on the development of the anthers. The later stages of development and anthesis are completed only on mature plants under short days (SD, 8 h light per day). Under long days (LD, 20 h light per day) senescence occurs in the early stages of anther wall differentiation.

ISSN:0008-4026    

DOI:10.1139/b78-223

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

A 2.6-m-thick subfossil peat deposit, composed entirely of the arctic mossAplodon wormskioldii, is described from the Carey Islands, northwestern Greenland (76°44′ N, 73°13′ W). Radiocarbon dates indicate that the peat began forming approximately 6500 years ago and stopped forming some 4500 to 4000 years ago; thus, its growth coincided with the postglacial warm period (Hypsithermal interval). The present-day habitat ofA. wormskioldii, on dung or otherwise enriched substrates, is difficult to reconcile with its persistence and abundance at a specific site in the high arctic for over two millenia.

ISSN:0008-4026    

DOI:10.1139/b78-224

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Morphological, developmental, and cytochemical studies on the apical apparatuses of five species, i.e.,Peziza succosa, Ascobolus crenulatus, Saccobolus depauperatus, Thecotheus pelletieri, andIodophanus granulipolaris, were performed with light and electron microscopy. Asci of all species, exceptA. crenulatus, stain blue in Melzer's reagent. The site of the iodine-positive reaction is believed to be an exogenous mucilaginous coat inP. succosa, S. depauperatus, andT. pelletieri. InI. granulipolaris, the reaction site appears to be the ascal wall. The presence of an annular indentation was found in the ascal tips of all species exceptI. granulipolaris. A line of dehiscence was found in the lower region of the annular indentation inT. pelletieriandS. depauperatus. The development of the apical apparatuses of all species occurs during and after late ascosporogenesis. The apical apparatus ofI. granulipolarisdiverged significantly in morphology and cytochemistry from the other species.

ISSN:0008-4026    

DOI:10.1139/b78-225

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Morphological, developmental, and cytochemical studies were made on the apical apparatus of nine members of the families Otideaceae and Aleuriaceae, referred to as theOtidea–Aleuriacomplex, andAscozonus woolhopensis. Special attention was paid to peculiar structures and the time of their appearance during ascosporogenesis. Subopercular rings were found in seven species. First appearance of the ring occurs at different stages of ascal development for different species. Formation of the ring generally marks the initiation of the development of the apical apparatus. For the most part, those species which have thick, 700–1000 nm, lateral walls possess less conspicuous subopercular rings than those species which have thin, 300–400 nm, lateral walls. Distinct zones or lines of dehiscence were not detected in any species. The apical apparatus ofA. woolhopensisresembles that ofAnthracobia melaloma. The apical apparatus of individual species is variable and can be useful in helping to determine taxonomic affinities.

ISSN:0008-4026    

DOI:10.1139/b78-226

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Molybdenum deficiency decreased the dry matter yield, tissue concentration of molybdenum, and chlorophyll content of corn (Zea maysL. cv. T.41) plants. Compared with the normal (control) plants, leaves of molybdenum-deficient plants had significantly lower activities of nitrate reductase, catalase, aldolase, and alanine aminotransferase and higher activities of peroxidase, β-glycerophosphatase, and ribonuclease. Within 72 h of supplying molybdenum (50 μM) to molybdenum-deficient plants, chlorophyll concentration, soluble protein, and activities of nitrate reductase, catalase, and alanine aminotransferase showed considerable recovery but the increase in the peroxidase activity was further enhanced. Supply of molybdenum to molybdenum-deficient plants did not significantly affect the activity of aldolase, ribonuclease, and β-glycerophosphatase.

ISSN:0008-4026    

DOI:10.1139/b78-227

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Morphology and morphogenesis of synnemata ofCeratocystis ulmiwere observed under a scanning electron microscope and a transmission electron microscope. Synnematal development inC. ulmican be divided into four stages: (1) synnema initial formation, (2) stalk development, (3) conidiophore formation, and (4) conidium production. Observations on each stage of development are described and illustrated.

ISSN:0008-4026    

DOI:10.1139/b78-228

出版商:NRC Research Press    

年代:1978

数据来源: NRC

摘要:

Chromosomal proteins from a wide range of seeds of coniferous species and from provenances of jack pine were characterized by polyacrylamide gel electrophoresis. Histones were resolved into five main fractions. The very lysine-rich F1 histone contained five subfractions. The electrophoretic properties of the nonhistone chromosomal proteins (NHCP) were distinctly different from histones and also from the soluble proteins of the cytoplasm and nucleus. The NHCP fraction contained 18 to 25 protein fractions with molecular weights from 9400 to over 68 000.Histones from nine species ofPinuswere similar electrophoretically. Minor differences were noted in mobilities of subfractions of the very lysine-rich F1 fraction. Histones of dry seeds from seven provenances ofPinus banksiana, while qualitatively similar, revealed only minor differences in the percentage distribution of the histone fractions.The relative distributions of the NHCP on discontinuous polyacrylamide gels were different in all seven provenances and in two of the provenances, additional NHCP were present.Comparison of the NHCP ofPinus, Picea, Abies, Pseudotsuga, andLarixspecies presented a range of quantitative and qualitative differences over and above that found among some species of one genus such asPinus.

ISSN:0008-4026    

DOI:10.1139/b78-229

出版商:NRC Research Press    

年代:1978

数据来源: NRC