Respiratory activity of fungal associations in zones of heart rot and stain in sugar maple

1968 ◽  
Vol 46 (1) ◽  
pp. 27-36 ◽  
Author(s):  
H. M. Good ◽  
J. T. Basham ◽  
S. D. Kadzielawa

Some of the progressive changes in decay in maple trees were studied by comparing total activity of the decay community (as measured by carbon dioxide output of excised samples), water content, pH, and predominant microorganisms (as shown by isolation on malt agar) in zones selected across the pocket of decay.Four trees from which Fomes igniarius were isolated gave consistent results with alkaline pH, high moisture content, and a predominance of imperfect fungi in the zones of incipient decay. Surprisingly, these zones showed the highest rates of carbon dioxide output, though they were only slightly higher than those of the transition zones. The center, severely decayed, parts of the trees were slightly acid, appreciably drier, and contained F. igniarius in abundance. They showed only about half the rate of carbon dioxide production of the outer zones. A section of rot caused by Polyporus glomeratus corresponded in most respects to those with F. igniarius.In samples of two regions from which no basidiomycete decay fungus was isolated, the pattern was completely different. In these the pH was consistently alkaline all across the pocket, exceeding pH 9 in one central area, and was highest in the central zone. The moisture content of these two trees was very high, being highest in the central zones, and the carbon dioxide production was much higher than that of the F. igniarius decays.

1935 ◽  
Vol 12 (5) ◽  
pp. 627-645 ◽  
Author(s):  
R. K. Larmour ◽  
J. S. Clayton ◽  
C. L. Wrenshall

Respiration and heating studies were made on hard red spring wheat.Estimation of the true respiration of hard red spring wheat is complicated by the respiration of fungi which develop on damp wheat. The germination and growth of fungi can be controlled effectively by toluene or carbon tetrachloride vapor. In the presence of vapor of these substances carbon dioxide production goes on at a low rate and no heating occurs in wheat of 25% moisture content. The odor of the vapor disappears in the course of air-drying.Exposure of damp wheat to carbon tetrachloride for 25 days produced no deleterious effect on the quality.


1953 ◽  
Vol 31 (1) ◽  
pp. 33-62
Author(s):  
Dorothy F. Forward

A survey of the course of carbon dioxide output of potato tubers upon transfer from air to nitrogen shows that the form of drift in nitrogen undergoes metamorphosis with the lapse of time between harvest and the anaerobic experience. A stable form is attained about three months from harvest.On restoration of air after nitrogen a temporary outburst of carbon dioxide occurs, and both form and magnitude of this after-effect change with time elapsed after harvest. The magnitude is also influenced by the duration of anaerobiosis. At any season, increased time in nitrogen produces an increased after-effect of more than proportionate magnitude. The rate of carbon dioxide output in air after nitrogen ultimately becomes steady, but is not necessarily equivalent to that preceding anaerobiosis. For the space of about three months, subjecting a tuber to nitrogen for two days or more at 22 °C. causes the ultimate rate of carbon dioxide output in air to remain well above that preceding anaerobiosis, while it bears a constant ratio to the final rate in nitrogen before air was restored. This permanent displacement of the rate in air is not at any time brought about by an anaerobic period of only one day.The nature of the drifts in metabolic state of the tubers that underlie these metamorphic changes in response to a period of anaerobiosis is still under investigation.


1944 ◽  
Vol 22c (4) ◽  
pp. 150-161 ◽  
Author(s):  
William Leach

Under the experimental procedure used in these researches it was found that wheat, when kept at 25 °C. in atmospheres of relative humidities between approximately 92 and 100%, showed a continuously accelerating rate of carbon dioxide output. This acceleration of rate increased as the relative humidity of the surrounding air was increased and was more pronounced in wheat from which the germs had been removed than in undamaged wheat. Where unlimited absorption of water and germination of the wheat are prevented, the carbon dioxide production by the grain is due almost entirely to the respiration of micro-organisms that infect it.


Author(s):  
César Andrade ◽  
Fátima Viveiros ◽  
J. Virgílio Cruz ◽  
Rui Coutinho

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