Water Content of Fungus Spores

Yarwood, C. E.

doi:10.1002/j.1537-2197.1950.tb11052.x

Cited by 41 publications

(19 citation statements)

References 5 publications

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“…A tentative hypothesis was advanced by Yarwood (1950) to account for the widespread occurrence in fungi of spore swelling before germ-tube emergence. He pointed out that the spores of powdery mildews which have a high water content produce germ-tubes without prior swelling and suggested that in other fungi water has to be absorbed to bring the spore to a degree of hydration similar to that of the powdery mildews before germ-tube emergence can occur.…”

Section: Discussionmentioning

confidence: 99%

The Germination of Sporangiospores of Rhizopus arrhizus; Spore Swelling and Germ-Tube Emergence

Ekundayo

Carlile

1964

Journal of General Microbiology

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SUMMARYThe germination of sporangiospores of Rhixopw arrhizw was investigated, and differing requirements found for the initiation of germination, spore swelling and germ-tube emergence. The initiation of germination, as indicated by the commencement of swelling and by the spores becoming permeable to methylene blue, requires the presence of glucose or fructose. Maximal spore swelling requires in addition the presence of a nitrogen source, PO:-and K+ or Na+. If these requirements are satisfied, the increase in spore diameter with time is approximately linear for 8 hr,implying the maintenance of a constant rate of water uptake per unit area of spore surface for this period. If germinating spores are transferred to a medium lacking glucose, swelling soon ceases. The rate of swelling is identical at widely differing osmotic pressures. It is suggested that water uptake by the germinating spore is an active process, requiring energy. Germtube emergence from some spores can be obtained with glucose alone, but for germ-tube production from all spores other nutrients must also be supplied. If glucose is present, spores can take up sufficient nutrients in 1-2 hr to permit complete germination in the absence of exogenous nutrients several hours later. Depending on conditions, germ-tube production can occur after either slight or massive spore swelling. The effect of anaerobic conditions on germination was also examined and found to permit only partial spore swelling and greatly diminished germ-tube production.

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Section: Discussionmentioning

confidence: 99%

The Germination of Sporangiospores of Rhizopus arrhizus; Spore Swelling and Germ-Tube Emergence

Ekundayo

Carlile

1964

Journal of General Microbiology

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“…No information, however, is available on the effect of intermittent dry periods on infection and sporulation of B. cinerea. The water content of ungerminated B. cinerea conidia is low (Yarwood, 1950), thus they have to take up water for germination and infection. During shorter infection promoting periods higher humidity values will be required in the glasshouse compared to those found in climate chamber experiments.…”

Section: Discussionmentioning

confidence: 99%

Control of Botrytis cinerea in glasshouse fuchsia by specific climate management

Friedrich¹,

Gebelein²,

Boyle³

2005

Eur J Plant Pathol

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The effect of climate management as a tool for integrated control of Botrytis cinerea in fuchsia culture was studied in two glasshouse experiments. This included: (i) a conventional, temperature based (T) and (ii) a humidity/temperature based (HT) climate control. When neighbouring plants came in contact with one another, a novel, economical method of direct ventilation of the canopy was employed as an additional treatment in each glasshouse. Despite significant differences in plant growth, no distinct effects on the susceptibility of clonal fuchsia plants or on the growth rate of stem blight lesions within the canopy were found for the different climate managements. Using the HT strategy, the canopies were effectively dehumidified during the night in contrast to the T management. Towards the end of the cultivation, a period with dense canopies, direct ventilation was most effective in dehumidifying the canopy. The differences in microclimate were correlated with B. cinerea stem infection and sporulation incidence. Best results were achieved using a combination of the HT strategy with direct ventilation, reducing stem blight values to less than a third as compared to the T management. With regard to plant health, climate management in glasshouses can only be improved by specific manipulation of the canopy climate: in presence of susceptible plant tissue, a management providing vapour pressure deficit values within the canopy above 1 hPa, or more safely, 1.5 hPa, is recommended.

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“…The survival probability of Aspergillus terreus in vacuum is related to the ability of the membrane to absorb the hydration stress from dehydration in vacuum. At low and high pumping speed, 10%-60% and 90-85 % respectively of the water content of the cell evaporates respectively (Yarwood, 1950;Bosmans, 1974).…”

Section: Spores In Vacuum At 10 -4 Pa and 298 Kmentioning

confidence: 99%

Interplanetary survival probability of Aspergillus terreus spores under simulated solar vacuum ultraviolet irradiation

Sarantopoulou¹,

Gomoiu²,

Kollia³

et al. 2011

Planetary and Space Science

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This work is a part of ESA/EU SURE project aiming to quantify the survival probability of fungal spores in space under solar irradiation in the vacuum ultraviolet (VUV) (110-180 nm) spectral region. The contribution and impact of VUV photons, vacuum, low temperature and their synergies, on the survival probability of Aspergillus terreus spores is measured at simulated space conditions on Earth. To simulate the solar VUV irradiation, the spores are irradiated with a continuous discharge VUV hydrogen photon source and a molecular fluorine laser, at low and high photon intensities at 10 15 photon m -2 s -1 and 3.9 x 10 27 photons pulse -1 m -2 s -1 respectively. The survival probability of spores is independent from the intensity and the fluence of photons, within certain limits, in agreement with previous studies. The spores are shielded from a thin carbon layer, which is formed quickly on the external surface of the proteinaceous membrane at higher photon intensities at the start of the VUV irradiation. Extrapolated the results in space conditions, for an interplanetary direct transfer orbit from Mars to Earth, the spores will be irradiated with 3.3 x 10 21 solar VUV photons m -2 . This photon fluence is equivalent to the irradiation of spores on Earth with 54 laser pulses with an experimental ~92% survival probability, disregarding the contribution of space vacuum and low temperature, or to continuous solar VUV irradiation for 38 days in space near the Earth with an extrapolated ~61% survival probability. The experimental results indicate that the damage of spores is mainly from the dehydration stress in vacuum. The high survival probability after 4 days in vacuum (~34 %), is due to the exudation of proteins on the external membrane, preventing thus further dehydration of spores. In addition, the survival probability is increasing to (~54%) at 10 K with 0.12 K/s cooling and heating rate.

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Water Content of Fungus Spores

Cited by 41 publications

References 5 publications

The Germination of Sporangiospores of Rhizopus arrhizus; Spore Swelling and Germ-Tube Emergence

The Germination of Sporangiospores of Rhizopus arrhizus; Spore Swelling and Germ-Tube Emergence

Control of Botrytis cinerea in glasshouse fuchsia by specific climate management

Interplanetary survival probability of Aspergillus terreus spores under simulated solar vacuum ultraviolet irradiation

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