摘要:

The influence of wide spectrum illumination conditions, with red and far-red light mixed to simulate sun and shade conditions, upon rates of photosynthesis and translocation was observed. A steady-state14CO2labeling apparatus was used to measure the two processes simultaneously during a light quality change. Sun conditions supported lower rates of photosynthesis and translocation to illuminated sink leaves than shade conditions, but the rate of translocation was lower than expected on the basis of the decline in photosynthesis. Translocation rates to darkened sinks remained constant as the photosynthetic rates were altered by changing light quality. Sink leaflet growth rates were lower in sun than shade light. We conclude that this decline in growth rate, which is also a decline in sink strength, results in light quality exerting a smaller effect on translocation than on photosynthesis.

ISSN:0008-4026    

DOI:10.1139/b82-164

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Small beech trees were cultivated in a nursery under different climates, outdoors in the field under a climate with seasonal variations, and indoors in a greenhouse under an unvarying climate. The 1st year, in the field and in the greenhouse, all axes were orthotropic with "juvenile" leaves, whatever the number of cycles of elongation, one in the greenhouse and one to five in the field. The 2nd year, only one cycle of elongation was observed in the greenhouse but one or two cycles appeared in the field. Plagiotropic axes, with "adult" leaves, appeared during the first cycle and orthotropic axes, with "juvenile" leaves during the second cycle. The following years the growth of trees was the same as the second year, but annual polycyclic shoots became rare and orthotropic organs less frequent.

ISSN:0008-4026    

DOI:10.1139/b82-165

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Rates of leaf starch accumulation in maize, wheat, and pangola grass were approximately doubled when plants were shifted from long to short day lengths, 4 days prior to measurement. There were only small changes in carbon assimilation rates and specific leaf weights. After a brief exposure to14CO2and after a 2-h-chase period, total label was higher in leaves of long to short day length than in long day length plants. Most of the increased14C radioactivity in leaf extracts of long to short day length plants was recovered in the starch, protein, and neutral fractions. The translocation of14C-labeled assimilates to roots was less in long to short day length then in long day length plants. Sucrose was increased in leaves and decreased in roots following a shift from long to short day lengths. The above findings indicated that the accumulation of assimilates in leaves of long to short day length plants was due in part to a lowered rate of sucrose transport. The rate of sucrose movement was not directly proportional to its total pool size in source leaves.

ISSN:0008-4026    

DOI:10.1139/b82-166

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The decomposition and organic chemical changes in Scots pine (Pinus silvestris) needle litter were studied for a period of 5 years and until 75% weight loss was reached in field incubation. The changes in components such as various groups of lipophilic extractives, low-molecular carbohydrates, cyclitols, phenolic glycosides, polysaccarides, and lignin were followed. There was a great drop of sugars, steryl esters, and triglycerides during the 1st year of decomposition. Some isoprenoid alcohols, sterols, and some acids belonged to the most stable of the soluble components. Of the solid residue the arabinans decomposed rapidly, the cellulose decomposed somewhat faster than the hemicelluloses as a group, and the lignin decomposed rather slowly (about 48% in 5 years).

ISSN:0008-4026    

DOI:10.1139/b82-167

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The microscopical study of the two anamorphs ofGnomonia leptostyla(Fr.) Ces. et de Not. shows the structural similarity of the conidiomata and the same phialidic mode of conidiogenesis. Moreover one phialide is able to give rise to the two kinds of conidia (macro- and micro- conidia). It is proposed to unite the anamorphs under the generic nameMarssoniella juglandis(Lib.) Höhnel emend Roquebert and Fayret.

ISSN:0008-4026    

DOI:10.1139/b82-168

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Dry weights of stipes and pilei ofFlammulina velutipesgrown on nutrient-supplemented sawdust increased throughout the growth period. The pilei weighed only slightly less than the stipes. Amounts of total organic nitrogen, α-amino nitrogen, and alkali-soluble protein increased in the whole pileus and stipe as the fruitbodies elongated, but the concentrations on a dry weight basis decreased although they were always highest in the pileus. The concentration of alkali-insoluble nitrogen increased in both structures and was highest in the stipe. Concentrations of total nitrogen and protein in surface mycelium did not change significantly when fruitbodies formed but increased markedly when their growth ceased. An average of 8.3 mg dry weight of spores containing about 0.6 mg of nitrogen was released during the life of the fruitbody. Changes in 18 free and 17 protein amino acids were followed quantitatively in the pileus and stipe. Glutamic and aspartic acids and alanine were always among the four predominant free amino acids. Lysine and arginine concentrations remained low in the stipes but increased considerably in the expanding pilei. Ornithine levels increased strongly in the stipe during the early part of rapid elongation but remained almost constant and low in the pilei. Free proline was detected only in traces. Valine became the most abundant protein amino acid during elongation, especially in the stipe. There was very little bound methionine and cystine. In surface mycelium levels of free amino acids were low before fruiting and close to the end of fruitbody growth. Protein amino acids increased during that interval but their proportions remained virtually unchanged and valine was not predominant. The concentration of urea remained very low in both pilei and stipes during their growth.

ISSN:0008-4026    

DOI:10.1139/b82-169

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

InFlammulina velutipesgrown on potato–glucose solution the dry weight of mycelium decreased when fruitbodies elongated rapidly. Loss of dry weight by aborted primordia and stunted fruitbodies paralleled gains by large fruitbodies. These gains exceeded the losses by the rest of the colony and indicate that large fruitbodies derived their substrates both from the medium and from materials stored in the rest of the colony. Close to 43% of the organic nitrogen in the medium was consumed before fruitbodies formed and only 8% remained at the end of their growth. Concentrations of total nitrogen, α-amino nitrogen, and alkali-soluble protein declined in the mycelium during most of the growth of the fruitbodies and then remained constant except for a slight final increase in protein. Concentrations of these fractions also decreased in the small fruitbodies and stipes of large fruitbodies but increased in the pilei. Changes in total amounts of these fractions show that gains by all fruitbodies during elongation exceeded the losses by the mycelium and that part of their nitrogen continues to be derived from the medium. Changes in 18 free and 17 protein amino acids were followed quantitatively in the colony. Free arginine, glutamic acid, ornithine, and alanine predominated in the mycelium and small fruitbodies during early growth of the latter, but arginine and ornithine decreased steeply thereafter. During rapid elongation of the large fruitbodies the concentration of arginine increased strongly in the pilei. The increase was much less in the stipes, but successive changes in the rest of the colony suggest that arginine is translocated into the large pilei from the mycelium and possibly the small fruitbodies. Aspartic and glutamic acids, leucine, and alanine predominated in protein of the whole colony until the early growth of fruitbodies, but protein composition changed during rapid elongation. The proportion of valine increased in the mycelium and it became the most abundant bound amino acid in large stipes. [14C]Leucine was fed in replacement medium and incorporation of the label was determined in nitrogenous fractions of different colony portions at the onset and termination of fruitbody growth. Most of the label transported into fruitbodies was in the ethanol-soluble free amino acids.

ISSN:0008-4026    

DOI:10.1139/b82-170

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

A leafy twig fragment ofThuja occidentalisL. was isolated from sediments dating about 10 000 years before present (B.P.) from Manitoulin Island, Ont. This is the earliest known record ofThujaleaves in postglacial deposits in eastern North America.Thujamay have arrived in Ontario in association with boreal spruce forests, but was a component of early pine forests.

ISSN:0008-4026    

DOI:10.1139/b82-171

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Small sections of immature female strobili ofLarix deciduaMill, were culturedin vitro. Several adventitious buds and shoots developed from callus of stalk sections of strobili collected in early May from one of the trees sampled.

ISSN:0008-4026    

DOI:10.1139/b82-172

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

There are three cytotypes ofPolypodium virginianumL. in Ontario. These may be identified by macro- and micro-morphological characters. The most useful characters for identification are frond shape, tip lobing, shape of segment apices, spore size, cell size, and number of paraphyses per sorus. The triploid cytotype, which often overlaps the variation shown by the diploid and tetraploid, can be recognized by a high percentage of aborted spores.

ISSN:0008-4026    

DOI:10.1139/b82-173

出版商:NRC Research Press    

年代:1982

数据来源: NRC