Effects of simulated orbital light/dark cycles on the photosynthesis of mungbean, soybean and millet

Title:

Effects of simulated orbital light/dark cycles on the photosynthesis of mungbean, soybean and millet

Creator:

Sacher, R. and Burian, K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:386da1b9-7349-42c3-8f89-d636bdb4f8ef
uuid:386da1b9-7349-42c3-8f89-d636bdb4f8ef
urnnbn:urn:nbn:cz:aba007-000fkd

Type:

model:internalpart and TEXT

Format:

print

Description:

Crop plants in Closed Ecological Life Support Systems (CELSS), for future extended manned space missions, might use for photosynthesis natural sunlight rather than an artificial irradiation. In a low earth orbit (LEO: 300-600 km) space station CELSS, these plants would have to deal with very short light/dark cycles. As a result of the 90 min revolution period of the station around the earth, they would be subjected to approximately 60 min sunlight followed by 30 min darkness in the earth's shade. These orbital light/dark cycles were simulated in growth chambers, which was accompanied by control experiments under long-day conditions (16/8 h light/dark). In Phaseolus mungo L., Glycine max L. and Sorghum bicolor L. the net C02-uptake (PN) and stomatal conductance (gs), as well as 02-production and quantum yield (QY) were measured. P. mungo grown under orbital cycles was strongly affected by slow induction of photosynthesis and stomatal limitation, resulting in the photodestruction of pigment systems and leaf chlorosis. Stomata of G. max opened faster upon onset of irradiation, which resulted in a sufficient C02-supply to prevent photoinhibition. Stomata of S. bicolor opened very rapidly, and Pn resumed steady-state similar to that before the dark break, within the first minutes of the irradiation, thus utilizing the major part of the 60 min "day" for net carbon gain. These findings were supported by QY measurements of oxygen evolution. Strongly decreased QY in P. mungo compared to long-day grown plants indicated destruction in light-harvesting pigments and electron transport chains. No reduction in QY was observed in G. max and S. bicolor.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

215-223 and 57-65

Source:

Photosynthetica | 1994 Volume:30 | Number:2

Harvested from:

CDK

Metadata only:

false