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Start Over Coverage 227-232

2. Chain correlation between variables of gas exchange and yield potential in different winter wheat cultivars

Creator:
Jiang, G. M., Hao, N. B., Bai, K. Z., Zhang, Q. D., Sun, J. Z., Guo, R. J., Ge, Q. Y., and Kuang, T. Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
apparent quantum yield of CO2 fixation, compensation irradiance, cultivars with high and low yield potentials, dark respiration, flag leaf, net photosynthetic rate, stomatal conductance, transpiration, and water use efficiency
Language:
Multiple languages
Description:
Variables of gas exchange of flag leaves and grain yield potentials of five representative winter wheat (Triticum aestivum L.) cultivars varied greatly across different development stages under the same management and irrigation. The cultivars with high yield potential had higher net photosynthetic rate (PN), PPFD (photosynthetic photon flux density) saturated photosynthetic rate (Psat), stomatal conductance (gs), and maximum apparent quantum yield of CO2 fixation (Φm,app) than those with low grain yield, but their dark respiration rate (RD) and compensation irradiance (Ic) were remarkably lower. Compared with overall increase of yield potential of 71 % from low yield cultivars to high yield ones, PN, Psat, Φm,app, and gs were 13, 19, 57, and 32 % higher, respectively; but RD and Ic decreased by 19 and 76 %, respectively. Such difference was evidently large during anthesis stage (e.g., PN by 33 %), which indicated that this period could be the best for assisting further selection for better cultivars. However, transpiration rate (E) and water use efficiency (WUE) differed only little. At different development stages, especially at anthesis, PN and Psat were positively correlated with Φm,app, gs, and yield potential, and negatively correlated with RD and Ic. Thus the high-yield-potential winter wheat cultivars possess many better characters in photosynthesis and associated parameters than the low-yield cultivars. and G. M. Jiang ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Gas exchange and water use efficiency of three native tree species in Hunshandak Sandland of China

Creator:
Li, Y. G., Jiang, G. M., Niu, S. L., Liu, M. Z., Peng, Y., Yu, S. L., and Gao, L. M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
drought, ecological restoration, high irradiance, high temperature, Malus baccata, photochemistry efficiency, photosynthesis, plant tolerance, Prunus padus, Ulmus pumila, and water use efficiency
Language:
Multiple languages
Description:
Only three tree species, i.e. Ulmus pumila, Malus baccata, and Prunus padus, are distributed in Hunshandak Sandland (HS) in Inner Mongolia, China. Field studies of gas exchange and chlorophyll (Chl) fluorescence of these three tree species were conducted in three arid periods of growth season 2002. Net photosynthetic rate (PN), transpiration rate (E), stomatal conductance (gs), and Fv/Fm of U. pumila were higher than in M. baccata and P. padus, especially in the midday. Hence M. baccata and P. padus were more sensitive to high temperature and irradiance than U. pumila in HS. This may be a reason for wide distribution of U. pumila in HS. M. baccata and P. padus are adapted to the back slope of fixed dune, because the micro-habitat is relatively cool and less irradiated than the slope facing sun. Water use efficiency (WUE) of U. pumila was lower than that of M. baccata and P. padus, and thus U. pumila does not form forests in this region, because the soil is dry. and Y. G. Li ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Radiation use efficiency, chlorophyll fluorescence, and reflectance indices associated with ontogenic changes in water-limited Chenopodium quinoa leaves

Creator:
Winkel, T., Méthy, M., and Thénot, F.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
leaf water potential, net photosynthetic rate, PRI, quinoa, and water stress
Language:
Multiple languages
Description:
Net photosynthetic rate, radiation use efficiency, chlorophyll (Chl) fluorescence, photochemical reflectance index (PRI), and leaf water potential were measured during a 25-d period of progressive water deficit in quinoa plants grown in a glasshouse in order to examine effects of water stress and ontogeny. All physiological parameters except Fv/Fm were sensitive to water stress. Ontogenic variations did not exist in Fv/Fm and leaf water potential, and were moderate to high in the other parameters. The complete recovery of photosynthetic parameters after re-irrigation was related with the stability in Fv/Fm. PRI showed significant correlation with predawn leaf water potential, Fm', and midday Fv/Fm. Thus PRI and Chl fluorescence may help in assessing physiological changes in quinoa plants across different developmental stages and water status. and T. Winkel, M. Méthy, F. Thénot.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Regulation mechanism of excitation energy transfer in phycobilisome-thylakoid membrane complexes

Creator:
Li, Ye, Zhang, Jianping, Zhao, Jingquan, and Jiang, Lijing
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
absorption spectra, allophycocyanin, betaine, DCMU, fluorescence spectra, models of energy transfer, N-ethylmaleimide, photosystems 1 and 2, and state transition
Language:
Multiple languages
Description:
Regulation mechanism of excitation energy transfer between phycobilisomes (PBS) and the photosynthetic reaction centres was studied by the state transition techniques in PBS-thylakoid membrane complexes. DCMU, betaine, and N-ethylmaleimide were applied to search for the details of energy transfer properties based on the steady fluorescence measurement and individual deconvolution spectra at state 2 or state 1. The closure of photosystem (PS) 2 did not influence on fluorescence yields of PS1, i.e., energy could not spill to PS1 from PS2. When the energy transfer pathway from PBS to PS1 was disturbed, the relative fluorescence yield of PS2 was almost the same as that of PS2 in complexes without treatment. If PBSs were fixed by betaine, the state transition process was restrained. Hence PBS may detach from PS2 and become associated to PS1 at state 2. Our results contradict the proposed "spill-over" or "PBS detachment" models and support the mobile "PBS model". and Ye Li ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public