摘要:

Using axenic cultures,Lyophyllum palustreandGalerina paludosaare shown to parasitizeSphagnumin two diferent ways. Other agaric–bryophyte relationships were examined in light of this information. Gemmae are documented forSphagnum capillaceum.

ISSN:0008-4026    

DOI:10.1139/b81-011

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Leaf explants of mulberry (Mortis albaL.) derived from aseptically grown shoots and seedlings were cultured on Murashige and Skoog's medium. Normal and abnormal leaves were grown by varying the concentration of benzyladenine. They differed in the way of forming adventitious buds. In normal leaves bud initiation occurred exclusively at the cut ends of midribs after removing petioles, while in abnormal ones buds formed at any region on midribs and petioles. Histological observations were made to study different patterns of bud initiation.

ISSN:0008-4026    

DOI:10.1139/b81-012

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

A new pinaceous species is described from the Early Cretaceous (Albian) McMurray Formation of Alberta. The cone is partially lignitic with permineralized ovules, 13 cm long × 4 cm wide, and occurs in a siliceous sandstone matrix. Thin sections were made after embedding with bioplastic and infiltration of cut faces with epoxy. Externally the helically arranged flattened cone scales resemble those of extantPicea. Scales bear two inverted, winged ovules containing shrunken nucellar and megagametophyte tissue. The cone axis is slender and contains small wedges of secondary xylem lacking resin canals. Vascularization of the cone–scale complex is similar to the non-Pinusspecies of the Pinaceae with bract and scale traces separate at their origins. One large abaxial resin canal, 1 mm in diameter, accompanies the traces out into the scale for 1 cm before branching. Two large bundles of sclerenchyma accompany the scale vascular tissue and may have served to open the cone at maturity. The bract, small and triangular in outline, has a terete trace and two lateral resin canals. Cone and seed structure are closely comparable to fossil pinaceous generaPseudoaraucariaandPityostrobusand the non-Pinusgenera of the extant Pinaceae.

ISSN:0008-4026    

DOI:10.1139/b81-013

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

The zoospore type is described forGaertneriomyces, a genus in the new order Spizellomycetales, Chytridiomycetes. The nucleus lies in the posterior of the zoospore and it has a basal concavity. The kinetosome and nonfunctional centriole are located just distally to the concavity. Microtubulules radiate in the cytoplasm from a presumed microtubule organizing center consisting of two short, electron-opaque bars attached to the kinetosome. Mitochondria are predominantly in the posterior, and aggregates of lipid globules in the anterior of the zoospore. Microbodies are morphologically associated with the lipid and endoplasmic reticulum. They are also found along the sides of the nucleus and near the mitochondria.

ISSN:0008-4026    

DOI:10.1139/b81-014

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Metal uptake studies withCladina rangiferinashowed that the affinity for nickel was much lower than for copper or thallium. Nickel uptake was not decreased by the absence of light or oxygen or by pretreatment with metabolic inhibitors. Nickel uptake was not temperature dependent but was very dependent upon pH.Cation-exchange studies demonstrated that there was a stoichiometric exchange of Ni2+for Sr2+, and Cu2+for Sr2+. The exchange of Tl+for Sr2+was not stoichiometric, excess Tl+was accumulated in relation to the Sr2+released. The ratio of Sr2+:Tl+exchange increased with increasing Tl+availability from 1:9 (12.5 μmol Tl+available/g of lichen) to 1:2 (500 μmol Tl+available). Acid-treated lichen gave the expected exchange ratio of 1:2. Washing of the thalli with deionized water resulted in the continued loss of Tl+from acid-treated and liveC.rangiferina. Copper and nickel were not released in this manner.Increasing concentrations of copper and thallium produced a corresponding loss of potassium from the thallus. The potassium loss was initiated at low concentrations of copper and thallium whereas very high concentrations of manganese and nickel were required to bring about the same response.

ISSN:0008-4026    

DOI:10.1139/b81-015

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Gigaspora margaritawas increased in pot culture usingSorghum vulgare('Shallu'). Soil was treated with methyl bromide (102 mg/L) for 24 h or heat treated at 82 °C for 6 h and mixed with vermiculite. Tobacco (Nicotiana tabacum) NC 2326 was inoculated at transplating with 500 (in 1978) or 4050 (in 1979) azygospores per plant and fertilized at three levels. Positive responses in growth to inoculation and significantly greater numbers of spores were observed both years at only the lowest fertilization levels. In the 1978 test, frenching of tobacco occurred in only the low fertilization level. Significantly less frenching occurred in the mycorrhizal inoculated treatment than in the control.

ISSN:0008-4026    

DOI:10.1139/b81-016

出版商:NRC Research Press    

年代:1981

数据来源: NRC

摘要:

Mild drying in air or exposure to the osmoticum polyethylene glycol 6000 at 5, 10, or 20% (w/w) concentration stimulated germination rate ofSpirodela polyrhiza(duckweed) turions. Treatment of the turions for several days in polyethylene glycol 6000 induced rapid germination of the turions. This germination response provides a model system for the study of metabolic changes prior to and during turion germination.

ISSN:0008-4026    

DOI:10.1139/b81-017

出版商:NRC Research Press    

年代:1981

数据来源: NRC