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1.
To clarify the ecophysiological characteristics of plants growing on a coastal dune, net photosynthetic rate (Pn) and leaf conductance (g1) of three perennial species in Japanese coastal regions,Ischaemum anthephoroides (C4),Carex kobomugi (C3) andCalystegia soldanella (C3), were compared under controlled environmental conditions and field conditions at the kado-ori coast at Ohno Village, Ibaraki.I. anthephoroides achieved photosynthetic CO2 saturation at ca. 100 μll−1 intercellular CO2 concentration (C
1), and itsPn was not light-saturated at a high photosynthetically active photon flux density (PPFD) of 1000 μmol m−2s−1. This C4 species showed a high optimal leaf temperature forPn (35°C) and a lowg1 (0.1 mol H2O m−2s−1), permitting maintenance of the highest water use efficiency (WUE, the ratio ofPn to transpiration rate (Tr)) in the field among the three species. At light saturation,C. soldanella had the lowestPn andg1 and a similar carboxylation efficiency related toC
1 (Pn/C1 ratio) asCarex kobomugi. Calystegia soldanella also had a high optimal temperature forPn (30°C), and achieved higherWUE thanCarex kobomugi, as a result of efficient stomatal regulation. In contrast, at the optimum temperatureC. kobomugi had a highPn comparable toI. anthephoroides due to a highg1 of 0.3 mol H2O m−2s−1, but with high temperature treatmentsPn andg1 were significantly decreased.C. kobomugi always had the lowestWUE among the three species in the field. It is therefore clear thatI. anthephoroides is a heat-resistant species,Calystegia soldanella is a heat-enduring species andCarex kobomugi is a heat-evading species due to its eraly phenology. 相似文献
2.
R. J. Ritchie 《Photosynthetica》2010,48(4):596-609
Irradiance data software developed by the NREL Solar Radiation Laboratory (Simple Model of Atmospheric Radiative Transfer
of Sunshine, SMARTS) has been used for modelling photosynthesis. Spectra and total irradiance were expressed in terms of quanta [mol m−2 s−1, photosynthetic photon flux density, PPFD (400–700 nm)]. Using the SMARTS software it is possible to (1) calculate the solar spectrum for a planar surface for any given solar elevation angle, allowing for the attenuating effects
of the atmosphere on extraterrestrial irradiance at each wavelength in the 400–700 nm range and for the thickness of atmosphere
the light must pass through during the course of a day, (2) calculate PPFD vs. solar time for any latitude and date and (3) estimate total daily irradiance for any latitude and date and hence calculate the total photon irradiance for a whole year
or for a growing season. Models of photosynthetic activity vs. PPFD are discussed. Gross photosynthesis (P
g) vs. photosynthetic photon flux density (PPFD) (P
g
vs. I) characteristics of single leaves compared to that of a canopy of leaves are different. It is shown that that the optimum
irradiance for a leaf (Iopt) is the half-saturation irradiance for a battery of leaves in series. A C3 plant, with leaves having an optimum photosynthetic rate at 700 μmol m−2 s−1 PPFD, was used as a realistic worked example. The model gives good estimates of gross photosynthesis (P
g) for a given date and latitude. Seasonal and annual estimates of P
g can be made. Taking cloudiness into account, the model predicts maximum P
g rates of about 10 g(C) m−2 d−1, which is close to the maximum reported P
g experimental measurements. 相似文献
3.
By simultaneously analyzing the chlorophyll a fluorescence transient and light absorbance at 820 nm as well as chlorophyll fluorescence quenching, we investigated the
effects of different photon flux densities (0, 15, 200 μmol m−2 s−1) with or without 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the repair process of cucumber (Cucumis sativus L.) leaves after treatment with low temperature (6°C) combined with moderate photon flux density (200 μmol m−2 s−1) for 6 h. Both the maximal photochemical efficiency of Photosystem II (PSII) (F
v/F
m) and the content of active P700 (ΔI/I
o) significantly decreased after chilling treatment under 200 μmol m−2 s−1 light. After the leaves were transferred to 25°C, F
v/F
m recovered quickly under both 200 and 15 μmol m−2 s−1 light. ΔI/I
o recovered quickly under 15 μmol m−2 s−1 light, but the recovery rate of ΔI/I
o was slower than that of F
v/F
m. The cyclic electron transport was inhibited by chilling-light treatment obviously. The recovery of ΔI/I
o was severely suppressed by 200 μmol m−2 s−1 light, whereas a pretreatment with DCMU effectively relieved this suppression. The cyclic electron transport around PSI recovered
in a similar way as the active P700 content did, and the recovery of them was both accelerated by pretreatment with DCMU.
The results indicate that limiting electron transport from PSII to PSI protected PSI from further photoinhibition, accelerating
the recovery of PSI. Under a given photon flux density, faster recovery of PSII compared to PSI was detrimental to the recovery
of PSI or even to the whole photosystem. 相似文献
4.
The estuarine red alga,Bostrychia radicans, was subjected to osmotic stresses ranging from hypo-osmotic (9.9‰) to hyperosmotic conditions (37.4‰). The growth rate decreased
with increasing salinities and showed a maximum in a mesohaline medium, while the photosynthetic rate and the chlorophyll
a content increased under hyper-osmotic conditions. The rate of respiration remained constant over the salinity range tested.B. radicans revealed typical characteristics of “shade plants” having a low light compensation point at 3–4 μE m−2 s−1 correlated with a low photon flux density of 70–100 μE m−2 s−1 for saturation of photosynthesis. These physiological properties may explain the success ofB. radicans in estuarine habitats. 相似文献
5.
M. R. de la Peña 《Journal of applied phycology》2007,19(6):647-655
Two series of experiments were conducted to determine suitable growth factors for the mass propagation of the local algal
isolate Amphora sp. A higher growth rate of 0.2 doubling (μ) day−1 was attained at a lower photosynthetic photon flux density (PPFD; 11.4 μmol photon m−2s−1) compared to cultures exposed to higher levels of PPFD (16.1 μmol photon m−2s−1, −0.1 μ day −1; 31.3 μmol photon m−2s−1, 0.0 μ day−1). Cultures located inside the laboratory had a significantly higher cell density (133 × 104 cells cm−2) and growth rate (0.3 μ day−1) compared to those located outdoors (100 × 104 cells cm−2, 0.2 μ day−1). A comparison of nutrient medium across two locations showed that lipid content was significantly higher in cultures enriched
with F/2MTM (macronutrients + trace metals) and F/2MV (macronutrients + vitamins). Saturated fatty acids were also present
in high concentrations in cultures enriched with F/2M (macronutrients only). Significantly higher amounts of saturated fatty
acids were observed in cultures located outdoors (33.1%) compared to those located indoors (26.6%). The protein, carbohydrates
and n-6 fatty acid content of Amphora sp. were influenced by the location and enrichment of the cultures. This study has identified growth conditions for mass
culture of Amphora sp. and determined biochemical composition under those culture conditions.
Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines. 相似文献
6.
Two approaches to determine the fraction (μ) of mitochondrial respiration sustained during illumination by measuring CO2 gas exchange are compared. In single leaves, the respiration rate in the light (`day respiration' rate Rd) is determined as the ordinate of the intersection point of A–ci curves at various photon flux densities and compared with the CO2 evolution rate in darkness (`night respiration' rate Rn). Alternatively, using leaves with varying values of CO2 compensation concentration (Γ), intracellular resistance (ri) and Rn, an average number for μ can be derived from the linear regression between Γ and the product riċRn. Both methods also result in a number c* for that intercellular CO2 concentration at which net CO2 uptake rate is equal to –Rd. c* is an approximate value of the photocompensation point Γ* (Γ in the absence of mitochondrial respiration), which is related
to the CO2/O2 specificity factor of Rubisco Sc/o. The presuppositions and limitations for application of both approaches are discussed. In leaves of Nicotiana tabacum, at 22 °C, single leaf measurements resulted in mean values of μ = 0.71 and c* = 34 μmol mol−1. At the photosynthetically active photon flux density of 960 μmol quanta m−2 s−1, nearly the same numbers were derived from the linear relationship between Γ and riċRn. c* and Rd determined by single leaf measurements varied between 31 and 41 μmol mol−1 and between 0.37 and 1.22 μmol m−2 s−1, respectively. A highly significant negative correlation between c* and Rd was found. From the regression equation we obtained estimates for Γ* (39 μmol mol−1), Sc/o (96.5 mol mol−1) and the mesophyll CO2 transfer resistance (7.0 mol−1 m2 s).
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
Growth and extracellular polysaccharide production byPorphyridium cruentum were measured as a function of several culture parameters. Photon flux density of 75 μmol m−2 s−1 and CO2 concentration of 2.5% were found to be optimum for both growth and extracellular polysaccharide production. Interactive studies
on these two parameters further confirmed that at these levels of photon flux density and CO2, when applied together, both growth (5.9·107 cells per mL) and extracellular polysaccharide production (1.9 g/L) were at the maximum. Maximum growth and extracellular
polysaccharide production were observed at inoculum density of 106 cells per mL and aeration rate of 500 mL air per min per liter. 相似文献
8.
Differences in photosynthetic apparatus of leaves from different sides of the chestnut canopy 总被引:1,自引:0,他引:1
In crowns of chestnut trees the absorption of radiant energy is not homogeneous; leaves from the south (S) side are the most
irradiated, but leaves from the east (E) and west (W) sides receive around 70 % and those from north (N) face less than 20
% of the S irradiation. Compared to the S leaves, those from the N side were 10 % smaller, their stomata density was 14 %
smaller, and their laminae were 21 % thinner. N leaves had 0.63 g(Chl) m−2, corresponding to 93 % of total chlorophyll (Chl) amount in leaves of S side. The ratios of Chl a/b were 2.9 and 3.1 and of Chl/carotenoids (Car) 5.2 and 4.8, respectively, in N and S leaves. Net photosynthetic rate (P
N) was 3.9 μmol(CO2) m−2 s−1 in S leaves, in the E, W, and N leaves 81, 77, and 38 % of that value, respectively. Morning time (10:00 h) was the period
of highest P
N in the whole crown, followed by 13:00 h (85 % of S) and 16:00 h with 59 %. Below 500 μmol m−2 s−1 of photosynthetic photon flux density (PPFD), N leaves produced the highest P
N, while at higher PPFD, the S leaves were most active. In addition, the fruits from S side were 10 % larger than those from
the N side. 相似文献
9.
Stomatal and non-stomatal limitations to photosynthesis in field-grown grapevine cultivars 总被引:1,自引:1,他引:0
Diurnal changes of photosynthesis in the leaves of grapevine (Vitis vinifera × V. labrusca) cultivars Campbell Early and Kyoho grown in the field were compared with respect to gas exchanges and actual quantum yield
of photosystem 2 (ΦPS2) in late May. Net photosynthetic rate (PN) of the two cultivars rapidly increased in the morning, saturated at photosynthetic photon flux density (PPFD) from 1200
to 1500 μmol m−2 s−1 between 10:00 and 12:00 and slowly decreased after midday. Maximum PN was 13.7 and 12.5 μmol m−2 s−1 in Campbell Early and Kyoho, respectively. The stomatal conductance (gs) and transpiration rate changed in parallel with PN, indicating that PN was greatly affected by gs. However, the decrease in PN after midday under saturating PPFD was also associated with the observed depression of ΦPS2 at high PPFD. The substantial increase in the leaf to air vapour pressure deficit after midday might also contribute to decline
of gs and PN. 相似文献
10.
A hinoki stand was divided into the following two layers: one was a leafed upper layer consisting of leaves and woody elements,
such as stems, living branches and dead branches; the other was a leafless layer consisted of woody elements, such as stems
and dead branches. Photosynthetic photon flux density (PPFD) penetrating through the stand was measured in relation to the
silhouette area of leaves and woody elements. The silhouette area, on a ground area basis, was 11.2 ha ha−1 for leaves (leaf area index), 0.26 ha ha−1 for stems, 0.40 ha ha−1 for living branches and 0.69 ha ha−1 for dead branches, yielding a total wood silhouette area of 1.35 ha ha−1. The apparent extinction coefficient,K, was computed to be 0.420 ha−1 ha for the leafed layer, while the extinction coefficient of woody elements,K
c, was computed to be 1.01 ha−1 ha for the leafless layer. The cumulative wood silhouette area density from the top of the canopy down to a given depth increased
with an increase in the corresponding leaf area density within the leafed layer. The extinction coefficient of leaves,K
F, was estimated to be 0.367 ha−1 ha. Of the PPFD extinguished within the canopy, the fraction (K
F/K) due to leaves alone was evaluated to be 87.4%. 相似文献
11.
Y. Kitaya L. Xiao A. Masuda T. Ozawa M. Tsuda K. Omasa 《Journal of applied phycology》2008,20(5):737-742
Symbiotic dinoflagellates of the species Amphidinium are expected to be pharmaceutically useful microalgae because they produce antitumor macrolides. A microalgae production
system with a large number of cells at a high density has been developed for the efficient production of macrolide compounds.
In the present study, the effects of culture conditions on the cellular growth rate of dinoflagellates were investigated to
determine the optimum culture conditions for obtaining high yields of microalgae. Amphidinium species was cultured under conditions with six temperature levels (21–35°C), six levels of photosynthetic photon flux density
(15–70 μmol photons m−2 s−1), three levels of CO2 concentration (0.02–0.1%), and three levels of O2 concentration (0.2–21%). The number of cells cultured in a certain volume of solution was monitored microscopically and the
cellular growth rate was expressed as the specific growth rate. The maximum specific growth rate was 0.022 h−1 at a temperature of 26°C and O2 concentration of 5%, and the specific growth rate was saturated at a CO2 concentration of 0.05%, a photosynthetic photon flux density of 35 μmol photons m−2 s−1 and a photoperiod of 12 h day−1 upon increasing each environmental parameter. The results demonstrate that Amphidinium species can multiply efficiently under conditions of relatively low light intensity and low O2 concentration. 相似文献
12.
Photoautotrophic micropropagation of Spathiphyllum 总被引:2,自引:0,他引:2
In order to maximize yield, Spathiphyllum, an ornamental plant, was cultured in vitro in novel culture vessels termed Vitron. The best growth was obtained by culturing plantlets on sugar-free liquid medium under CO2 enrichment (3 000 μmol mol−1 24 h−1 d−1) at a low photon flux density (PPFD of 45 μmol m−2 s−1), suggesting that the novel Vitron culture system is suitable for the photoautotrophic micropropagation of Spathiphyllum. 相似文献
13.
Glaucium flavum is a biennial plant that bears a rosette of leaves, producing a flower stalk, bracteate monochasium, in its second year.
The aims of this work were both to investigate the contribution of bracts to gas-exchange activities in this species and to
compare this contribution to that of rosette leaves. In addition, we investigated the extent to which its responses can be
explained by chloroplast ultrastructure, as well as the possible role of nutrient concentrations in the physiological responses
of both leaf types. Gas exchange and plant characteristics regarding chlorophyll fluorescence were examined in a field experiment;
we also determined leaf relative water content, tissue concentrations of photosynthetic pigments, chloroplast ultrastructure
and nutrient contents. Although bracts indeed contributed to gas-exchange activities of G. flavum, rosette leaves showed higher values of net photosynthetic rate and stomatal conductance to CO2 for photosynthetic photon flux density above 200 μmol m−2 s−1. The incongruities in photosynthetic rates between bracts and leaves may be explained by the bigger chloroplasts of rosette
leaves, which results in a larger membrane surface area. This agrees with the higher pigment concentrations and quantum efficiency
of photosystem II values recorded as well for rosette leaves. On the other hand, bracts showed higher sodium concentrations,
which could be a mechanism for salt tolerance of G. flavum. 相似文献
14.
S. M. Renaud D. L. Parry Luong-Van Thinh C. Kuo A. Padovan N. Sammy 《Journal of applied phycology》1991,3(1):43-53
The total protein, carbohydrate, lipid and ash compositions, and fatty acid contents of two species of marine microalgae,
the eustigmatophyte Nannochloropsis oculata (formerly ‘Chlorella sp., Japan’) and the chrysophyte Isochrysis sp. (Tahitian) used in tropical Australian mariculture, were studied. The microalgae were grown under a range of culture
conditions (41 and 601 laboratory culture, 3001 bag culture, and 80001 outdoor culture) and four light regimes (100 to 107
μ E m−2 s−1, 240 to 390 μ E m−2 s−1, 340 to 620 μ E m−2 s−1, and 1100 to 1200 μE m−2 s−1 respectively) to determine the effect of light intensity on the chemical composition of large scale outdoor cultures. Laboratory
and bag cultures were axenic and cultured in Walne medium while outdoor cultures were grown in a commercial medium designed
for optimum nutrition in tropical outdoor aquaculture operations. Change in growth medium and photon flux density produced
only small changes in the proximate biochemical composition of both algae. N. oculata and Isochrysis sp. both showed a trend towards slightly lower carbohydrate and higher chlorophyll a in shaded outdoor culture. Isochrysis sp. showed significant concentrations of the essential polyunsaturated fatty acid 22:6(n−3) (docosahexaenoic acid) from 5.3
to 10.3% of total fatty acid, and 20:5(n−3) (eicosapentaenoic acid) ranged from 0.6 to 4.1%. In contrast, N. oculata had high concentrations of 20:5(n−3) (17.8 to 39.9%) and only traces of 22:6(n−3). The fatty acid composition of Isochrysis sp. grown at high photon flux density (1100–1200 μE m−2 s−1) under outdoor culture showed a decrease in the percentage of several highly unsaturated fatty acids, including 20:5(n−3),
and an increase in 22:6(n−3). N. oculata showed a similar decrease in the percentage of 20:5(n−3). High light intensity caused a decrease in the ratio of total C16 unsaturated fatty acids to saturated 16:0 in N. oculata, and a decrease in the ratio of total C18 unsaturated fatty acids to saturated 18:0 together with a decrease in the ratio of total unsaturated fatty acids to total
saturated fatty acids in both microalgae. 相似文献
15.
Iván Closa Juan José Irigoyen Nieves Goicoechea 《Trees - Structure and Function》2010,24(6):1029-1043
Beech forests naturally regenerating from clear-cutting can exhibit different microclimates depending on size of saplings
and stem density. When beech trees are young and stem density is low, the level of radiation inside the ecosystem reaching
the soil surface is high; consequently, air and soil temperatures rise and the soil water content may decrease. These microclimatic
parameters presumably will affect the anatomy, photosynthesis, and carbon metabolism of beech leaves. We studied the morphology
and physiology of sun and shade leaves of beech trees differing in age and growing within clear-cut areas with distinct microclimate.
Results were compared with those of adult trees in an unmanaged forest. We selected a stand clear-cut in 2001 (14,000 trees
ha−1), another clear-cut in 1996 (44,000 trees ha−1) and an unmanaged forest (1,000 trees ha−1). Photosynthetic photon flux density (PPFD) incident on sun leaves, air temperature, soil moisture, and soil temperature
within the forests affected water status and carbohydrate storage in all trees. As trees became older, PPFD also influenced
pigment composition and Rubisco activity in sun leaves. On the other hand, shade leaves from the oldest trees were the most
sensitive to PPFD, air temperature, and soil moisture and temperature inside the forest. Contrariwise, microclimatic parameters
slightly affected the physiology of shade leaves of the beech in the stand with the highest light attenuation. Air and soil
temperatures were the parameters that most affected the photosynthetic pigments and carbohydrate storage in shade leaves of
the youngest trees. 相似文献
16.
Intact leaves of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson) from plants grown in a range of controlled temperatures from 15/10 to 30/25°C were
exposed to a photon flux density (PFD) of 1500 μmol·m−2·s−1 at leaf temperatures between 10 and 25°C. Photoinhibition and recovery were followed at the same temperatures and at a PFD
of 20 μmol·m−2·s−1, by measuring chlorophyll fluorescence at 77 K and 692 nm, by measuring the photon yield of photosynthetic O2 evolution and light-saturated net photosynthetic CO2 uptake. The growth of plants at low temperatures resulted in chronic photoinhibition as evident from reduced fluorescence
and photon yields. However, low-temperature-grown plants apparently had a higher capacity to dissipate excess excitation energy
than leaves from plants grown at high temperatures. Induced photoinhibition, from exposure to a PFD above that during growth,
was less severe in low-temperature-grown plants, particularly at high exposure temperatures. Net changes in the instantaneous
fluorescence,F
0, indicated that little or no photoinhibition occurred when low-temperature-grown plants were exposed to high-light at high
temperatures. In contrast, high-temperature-grown plants were highly susceptible to photoinhibitory damage at all exposure
temperatures. These data indicate acclimation in photosynthesis and changes in the capacity to dissipate excess excitation
energy occurred in kiwifruit leaves with changes in growth temperature. Both processes contributed to changes in susceptibility
to photoinhibition at the different growth temperatures. However, growth temperature also affected the capacity for recovery,
with leaves from plants grown at low temperatures having moderate rates of recovery at low temperatures compared with leaves
from plants grown at high temperatures which had negligible recovery. This also contributed to the reduced susceptibility
to photoinhibition in low-temperature-grown plants. However, extreme photoinhibition resulted in severe reductions in the
efficiency and capacity for photosynthesis. 相似文献
17.
The effect of in vitro cultivation of donor shoots on subsequent morphogenesis in leaf explants of quince (Cydonia oblonga Mill.) clone BA29 was investigated. Proliferating donor shoots were cultured in ventilated or closed vessels under different
photosynthetic photon flux densities (PPFD; 200 and 100 μmol m−2 s−1) with 0, 15, 30 g dm−3 sucrose. Shoots grown in ventilated vessels, especially with sucrose at 15 or 30 g dm−3, were better developed with fully expanded leaves compared to those in standard closed vessels. Leaves collected from pre-treated
donor shoots were used to assess regeneration capacity. Somatic embryo production was highest in leaves harvested from shoots
cultured in closed vessels with 30 g dm−3 sucrose and in ventilated vessels with 15 and 30 g dm−3 sucrose and under high PPFD which was, in comparison with the control treatment (closed vessel, 30 g dm−3 sucrose and low PPFD), about 2 to 2.5 times higher. A similar response was observed for root regeneration. 相似文献
18.
Vegetative reproduction of Chondracanthus chamissoi by means of fragmentation and re-attachment of thalli is considered an effective strategy for maintaining natural populations
of this species. Here, we evaluate the effects of (1) time of drifting thallus, (2) type of substratum, and (3) photon flux
density, on the re-attachment capacity of thallus fragments of C. chamissoi. The results show that re-attachment decreases with the time after detachment, and was higher at the lower photon flux densities
tested (10 and 40 μmol photons m−2s−1), and on calcareous substratum. Secondary attachment discs are formed along the entire surface of the fragment. 相似文献
19.
The factors controlling biomass production and the synthesis of astaxanthin esters in the microalga Haematococcus pluvialis (CCAP 34/7) have been investigated using a statistical approach employing response surface methodology (RSM). The culture
conditions required for optimal growth and carotenogenesis in this alga are very different. Of particular importance is the
photon flux density: for growth the optimum is 50–60 μmol m−2 s−1 whereas the optimum for astaxanthin synthesis is much higher at ∼-1600 μmol m−2 s−1. The addition of low levels of NaCl to the medium also stimulates to a small extent synthesis of astaxanthin, but photon
flux density remains the overriding factor. The optimal temperature for this strain is quite low at 14–15 °C. RSM has been
shown to be a rapid and effective technique leading to the optimisation of algal culture conditions. This statistical approach
can be applied readily to the majority of microalgae and their products. 相似文献
20.
Dennis H. Greer 《Planta》1998,205(2):189-196
Bean (Phaseolus vulgaris L. cv. Long John) plants were grown with photoperiods of 6 and 16 h at constant photon flux density (PFD), giving a daily
photon receipt (DPR) of 17 and 48 mol · m−2 respectively. Vegetative growth was determined at regular intervals and diurnal whole-plant photosynthesis measured. Intact
trifoliate leaves were exposed to photoinhibitory treatments at PFDs of 800 and 1400 μmol · m−2 · s−1 at temperatures of 14 and 20 °C, both in the absence and presence of the inhibitors chloramphenicol and dithiothreitol. Fluorescence
and photon yields were determined at regular intervals throughout each treatment. Plants grown with photoperiods of 6 h had
significantly lower growth rates than those grown with 16-h photoperiod but no difference in net photosynthetic rates or photon
yields were found. Carbohydrate analyses confirmed short-day plants were strongly sink-limited. Long-day plants were slightly
sink-limited, with a high proportion of starch in the leaves and reduced photosynthesis between 13 and 16 h. Plants grown
in low DPR were more susceptible to photoinhibition, from sustained closure of some photosystem II reaction centres, than
plants grown in high DPR. Capacity for thermal dissipation appeared dependent on PFD while photochemical capacity was more
dependent on DPR.
Received: 6 June 1997 / Accepted: 17 September 1997 相似文献