摘要:

Black walnut pollen was germinated on liquid and agar-based media containing 20% sucrose, a requirement for germination and normal tube development. Boron (100 ppm boric acid) added to this medium slightly enhanced germination. Germination occurred only in dense (150+ grains/mm2) populations of pollen on the agar medium. This population effect was not overcome by the addition of Ca2+to the medium, but germination in the sparse areas (< 30 grains/mm2) was occasionally promoted by high boron concentrations (600 ppm boric acid). Wide tree-to-tree variation in percentage of germination was observed.Vacuum-drying periods, ranging from 5 to 30 min, resulted in a gradual reduction of viability. Pollen was stored at −30C and −196C for 3 months without major loss of viability.

ISSN:0008-4026    

DOI:10.1139/b71-120

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

This paper is a review dealing with the various structural and metabolic changes that have been described in the shoot apex in transition to flowering. Evaluation of the significance of these changes can tentatively be made only in cases wherea, the timing of physiological events in the plant, particularly the time of movement of the floral stimulus, is reasonably well known;b, the timing and localization of events in the shoot apex are known.For each of the best known cases (Xanthium, Pharbitis, Sinapis, Lolium, Chenopodium), the temporal sequence of events in the target cells of the apical meristem is described and the sequences are compared. Three successive phases of general occurrence are distinguished.1. Theevocation phase, including the events occurring at the presumed time of arrival of the floral stimulus at the meristem. During this phase, RNA and protein molecules essential to the flowering process are synthesized.2. Themitotic phase, characterized by the release in mitosis of cells that are in the postsynthetic G2phase of the mitotic cycle.3. Themorphogenesis phase, including the events leading to the production of flower buds.The essentiality and role of the phases are discussed in relation with current views on cell differentiation.

ISSN:0008-4026    

DOI:10.1139/b71-121

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

An undialyzable, thermostable inhibitor of tryptophan synthase from pea plants,Escherichia coli, andNeurospora crassaoccurs in the filtrate from acetone extraction of pea tissue. A procedure is described for purification of the inhibitor extracted from roots. The final, purified preparation is homogeneous as shown by disc electrophoresis on acrylamide gel. The molecular weight, estimated by gel filtration on Sephadex G-200, is about 18 000. The inhibitor is stable even on heating at pH 7.0 in a water bath at 100 °C and has a characteristic ultraviolet absorption spectrum. The inhibitor shows some protein-like properties and acid hydrolysates were found to contain substances sensitive to ninhydrin. However, the hydrolysates also contain substances, presumably sugars, sensitive to benzidine reagent, appreciable sugar in galactose equivalents, and some fluorescent substances. The inhibitor was also found in shoot tissue. In both root and shoot the inhibitor increases, on a protein basis, with age of the tissue.

ISSN:0008-4026    

DOI:10.1139/b71-122

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Heat transfer was studied from intact leaves of greenhouse-grownPhaseolus vulgarisL. under still and forced air conditions. Microwaves were used to heat the leaves without disturbing the thermal equilibrium of the environment. Leaf temperatures were measured by thermocouples and an infrared radiometer. Convective heat transfer coefficient for a leaf was obtained by two experimental methods and compared with the theoretical results. The unsteady-state method proved to be quite satisfactory.Typical values of heat transfer coefficient for free convection varied from 1.86 × 10−4to 3.64 × 10−4 cal cm−2 s−1 °C−1, as the temperature difference between the leaf surface and the surrounding air increased from 1.0 to 3.9 °C. Forced convective heat transfer coefficient, however, increased to about 10 × 10−4 cal cm−2 s−1 °C−1at 610 cm s−1.

ISSN:0008-4026    

DOI:10.1139/b71-123

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

An emended description of the family Onygenaceae (Ascomycota) is presented and a key to the seven genera given. Two new monotypic genera are described:Ascocalvatiagen. nov., with the type speciesA. alveolatasp. nov., has white puffball-like ascocarps and cylindrical ascospores;Xynophilagen. nov., with the type speciesX. mephitalissp. nov., has ascocarps clustered within a common tomentose layer. The remaining five genera of Onygenaceae,AphanoascusZukal,ArachnomycesMassee & Salmon,DichotomomycesScott,OnygenaFr., andThermoascusMiehe are briefly discussed.

ISSN:0008-4026    

DOI:10.1139/b71-124

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Four new monotypic genera of cleistothecial coprophilous Ascomycetes are described:Eremomyces bilateralisgen. and sp. nov. found on dung in Ontario, California, and Kenya, has hyaline, one-celled ascospores and is accommodated in Eremomycetaceae, a new family of the Loculoascomycetes;Mycorhynchidium saccatumgen. and sp. nov. found in Kenya belongs to the Nectriaceae and is similar toMycorhynchusSacc.;Cleistothelebolus nipigonensisgen. and sp. nov. found on wolf dung in Ontario, andLasiobolidium spiralegen. and sp. nov., represented by four collections on horse and cow dung from Nevada and Wyoming are members of the Eoterfeziaceae.

ISSN:0008-4026    

DOI:10.1139/b71-125

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

The Ascomycete genusKerniais emended according to revised concepts. Five species,K. bifurcotrichaSaxena & Mukerji,K. hippocrepidasp. nov.,K. nitida(Sacc.) Nieuwland, andK. pachypleurasp. nov., are included and a key to the species given. Two species,K. brachytricha(Ames) Benjamin andK. geniculotrichaSeth, are placed in synonymy withK. nitida. Three species,K. bartlettii(Massee & Salmon) Benjamin,K. furcotrichaTandon & Bilgrami, andK. spirotrichaBenjamin, are excluded fromKernia. K. bartlettiibelongs inLophotrichusBenjamin and is transferred to that genus asL. bartlettii(Massee & Salmon) Malloch & Cain.K. furcotrichais considered a possible species ofChaetomidium(Zopf) Sacc.K. spirotrichabelongs inChaetomidiumand is transferred asC. spirotrichum(Benjamin) Malloch & Cain. As a result of studies of the type specimen ofFairmania singularisSacc, since a Fairman collection under that name was included inK. hippocrepida, the new combinationMicroascus singularis(Sacc.) Malloch & Cain is proposed.

ISSN:0008-4026    

DOI:10.1139/b71-126

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

The family Sordariaceae is briefly defined and a list of cleistothecial genera given. Two species ofAnixiellaSaito & Minoura ex Cain,A. endodontasp. nov., andA. monosporasp. nov. are described and a key to the four species of the genus included.Apodus deciduusgen. et sp. nov. is described. Two new combinations inEchinopodosporaRobison,E. spinosa(Cailleux) Malloch & Cain andE. verruculosa(Cailleux) Malloch & Cain, are proposed to accept transfers fromTripterosporaCain and are followed by a key to species ofEchinopodospora. The concept ofZopfiellaWinter is broadened to includeZ. pleuroporasp. nov. and three new combinations,Z. inermis(Cailleux) Malloch & Cain,Z. latipes(Lundqvist) Malloch & Cain, andZ. leucotricha(Speg.) Malloch & Cain, transferred fromTripterospora. A key to the six species ofZopfiellais presented. The new family Coniochaetaceae is proposed to accommodate the new genusConiochaetidiumandConiochaeta(Sacc.) Massee. Two species ofConiochaetidiumare described,C. ostreumsp. nov. andC. savoryi(Booth) Malloch & Cain, comb, nov., based onThielavia savoryiBooth.

ISSN:0008-4026    

DOI:10.1139/b71-127

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Cultured tissues fromPseudotsuga menziesii(Mirb.) Franco were successfully inoculated withCronartium ribicolaJ. C. Fisch. ex Rabenh. Typical intracellular haustoria were formed 60 days after inoculation. Invaded nonhost tissues were necrotic within 90 days, and dead within 120 days. Tissue cultures of eitherPinus monticolaDougl. orP. menziesiihad an attractant effect on nearby rust mycelium.

ISSN:0008-4026    

DOI:10.1139/b71-128

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Maximum standing crop in anEleocharis quadrangulatapopulation was estimated at 881 g dry wt./m2. Net daily productivity was highest during May when about 50% of the total standing crop was produced. Net productivity for the entire period of vegetative increase, April 1 to August 4, was 7.0 g/m2per day. The accumulation of several nutrients, especially nitrogen, phosphorus, and potassium was proportionately more rapid than dry matter production during early spring growth. Net chlorophyll synthesis was also greater during early spring. Patterns of change in dry matter and chemical substances in theE. quadrangulatapopulation were similar to those in populations of other emergent aquatic macrophytes.

ISSN:0008-4026    

DOI:10.1139/b71-129

出版商:NRC Research Press    

年代:1971

数据来源: NRC