Publication Date:
2012-05-23
Description:
We aimed to understand the relation of photosynthetic rate ( A ) with g s and electron transport rate (ETR) in species of great taxonomic range and light adaptation capability during photosynthetic light induction. We studied three woody species ( Alnus formosana , Ardisia crenata and Ardisia cornudentata ) and four fern species ( Pyrrosia lingus , Asplenium antiquum , Diplazium donianum and Archangiopteris somai ) with different light adaptation capabilities. Pot-grown materials received 100 and/or 10% sunlight according to their light adaptation capabilities. At least 4 months after light acclimation, CO 2 and H 2 O exchange and chlorophyll fluorescence were measured simultaneously by equipment in the laboratory. In plants adapted or acclimated to low light, dark-adapted leaves exposed to 500 or 2000 µmol m –2 s –1 photosynthetic photon flux (PPF) for 30 min showed low gross photosynthetic rate ( P g ) and short time required to reach 90% of maximum P g (). At the initiation of illumination, two broad-leaved understory shrubs and the four ferns, especially ferns adapted to heavy shade, showed higher stomatal conductance ( g s ) than pioneer tree species; materials with higher g s had short at both 500 and 2000 µmol m –2 s –1 PPF. With 500 or 2000 µmol m –2 s –1 PPF, the g s for the three woody species increased from 2 to 30 min after the start of illumination, but little change in the g s of the four ferns. Thus, P g and g s were not correlated for all material measured at the same PPF and induction time. However, P g was positively correlated with ETR, even though CO 2 assimilation may be influenced by stomatal, biochemical and photoinhibitory limitations. In addition, was closely related to time required to reach 90% maximal ETR for all materials and with two levels of PPF combined. Thus, ETR is a good indicator for estimating the light induction of photosynthetic rate of species, across a wide taxonomic range and light adaptation and acclimation capability.
Print ISSN:
0829-318X
Electronic ISSN:
1758-4469
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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