Effect of ultraviolet-B radiation on growth, photosynthetic pigments, and cell biology of Kappaphycus alvarezii (Rhodophyta, Gigartinales) macroalgae brown strain

É. C. Schmidt, B. G. Nunes, M. Maraschin, Z. L. Bouzon

Photosynthetica 2010, 48(2):161-172 | DOI: 10.1007/s11099-010-0022-7

Kappaphycus alvarezii is a seaweed of great economic importance for the extraction of kappa carrageenan from its cell walls. The most common strains are dark red, brown, yellow, and different gradations of green. It is known that ultraviolet radiation (UVR) affects macroalgae in many important ways, including reduced growth rate, reduction of primary productivity, and changes in cell biology and ultrastructure. Therefore, we examined the brown strain of K. alvarezii exposed to ultraviolet-B radiaton (UVBR) for 3 h per day during 28 days of cultivation. The control plants showed growth rates of 7.27% d^-1, while plants...

Comparative photosynthesis, growth, productivity, and nutrient use efficiency among tall- and short-stemmed rain-fed cassava cultivars

M. A. El-Sharkawy, S. M. De Tafur

Photosynthetica 2010, 48(2):173-188 | DOI: 10.1007/s11099-010-0023-6

Field trials under rain-fed conditions at the International Center for Tropical Agriculture (CIAT) in Colombia were conducted to study the comparative leaf photosynthesis, growth, yield, and nutrient use efficiency in two groups of cassava cultivars representing tall (large leaf canopy and shoot biomass) and short (small leaf canopy and shoot biomass) plant types. Using the standard plant density (10,000 plants ha^-1), tall cultivars produced higher shoot biomass, larger seasonal leaf area indices (LAIs) and greater final storage root yields than the short cultivars. At six months after planting, yields were similar in both plant types with...

Stomatal development and associated photosynthetic performance of capsicum in response to differential light availabilities

Q. S. Fu, B. Zhao, Y. J. Wang, S. Ren, Y. D. Guo

Photosynthetica 2010, 48(2):189-198 | DOI: 10.1007/s11099-010-0024-5

The mechanisms of capsicum growth in response to differential light availabilities are still not well elucidated. Hereby, we analyzed differential light availabilities on the relationship between stomatal characters and leaf growth, as well as photosynthetic performance. We used either 450-500 µmol m^-2 s^-1 as high light (HL) or 80-100 µmol m^-2 s^-1 as low light (LL) as treatments for two different cultivars. Our results showed that the stomatal density (SD) and stomatal index (SI) increased along with the leaf area expansion until the peak of the correlation curve, and then decreased. SD and SI...

Why is it better to produce coffee seedlings in full sunlight than in the shade? A morphophysiological approach

G. A. B. K. Moraes, A. R. M. Chaves, S. C. V. Martins, R. S. Barros, F. M. DaMatta

Photosynthetica 2010, 48(2):199-207 | DOI: 10.1007/s11099-010-0025-4

The coffee plant is native to shaded environments and its seedlings are often produced in shaded nurseries. However, some nursery managers, in an effort to improve the acclimation of seedlings to field conditions after transplantation, produce seedlings in full sun exposure. In this study, the morphological and physiological parameters of arabica coffee (Coffea arabica) seedlings produced in full sun (T1) and in shade (T2) were examined. The biomass accumulation and relative growth rate of T1 and T2 seedlings were similar. The T1 seedlings had less biomass allocation to shoots, a lower leaf mass ratio and a lower leaf area ratio; however, they...

Effect of fertilizer application on photosynthesis and oil yield of Jatropha curcas L.

J. W. H. Yong, Y. F. Ng, S. N. Tan, A. Y. L. Chew

Photosynthetica 2010, 48(2):208-218 | DOI: 10.1007/s11099-010-0026-3

The use of Jatropha curcas oil as a source of biofuel has been well-explored. However, the physiological and growth studies of J. curcas have received considerably lesser attention. In this study, leaf gas exchange measurements and leaf nitrogen content were determined for four varieties of J. curcas, grown in the field or in pots. Based on stable carbon isotope analysis (δ¹³C) and gas-exchange studies, J. curcas is a C₃ sun plant and the range of leaf photosynthetic rates (or CO₂ assimilation rates, P _Nmax) were typically between 7 and 25 μmol(CO₂) m^-2...

Light distribution in leaf chambers and its consequences for photosynthesis measurements

S. W. Hogewoning, G. Trouwborst, J. Harbinson, W. Van Ieperen

Photosynthetica 2010, 48(2):219-226 | DOI: 10.1007/s11099-010-0027-2

The impact of a heterogeneous distribution of actinic light within a leaf chamber for photosynthetic measurements by gas exchange on the photosynthesis-irradiance relationship was investigated. High-resolution light distributions were measured over the area of a commercially available clamp-on leaf chamber equipped with build-in red and blue LEDs, as well as over the area of a custom-made leaf chamber with external light source, using a low-cost digital camera and freely available software. The impact of the measured heterogeneity on the photosynthesis-irradiance response curve was calculated for two realistic scenarios. When the average light intensity...

Root nutrient uptake enhances photosynthetic assimilation in prey-deprived carnivorous pitcher plant Nepenthes talangensis

A. Pavlovič, L. Singerová, V. Demko, J. Šantrůček, J. Hudák

Photosynthetica 2010, 48(2):227-233 | DOI: 10.1007/s11099-010-0028-1

Carnivorous plants grow in nutrient-poor habitats and obtain substantial amount of nitrogen from prey. Specialization toward carnivory may decrease the ability to utilize soil-derived sources of nutrients in some species. However, no such information exists for pitcher plants of the genus Nepenthes, nor the effect of nutrient uptake via the roots on photosynthesis in carnivorous plants is known. The principal aim of present study was to investigate, whether improved soil nutrient status increases photosynthetic efficiency in prey-deprived pitcher plant Nepenthes talangensis. Gas exchange and chlorophyll (Chl) fluorescence were...

Photosynthetic characteristics in Oryza species

M. Zhao, Z. Ding, R. Lafitte, E. Sacks, G. Dimayuga, D. Holt

Photosynthetica 2010, 48(2):234-240 | DOI: 10.1007/s11099-010-0029-0

Photosynthetic rate (P _N), SPAD value, specific leaf area (SLA), flag leaf area (FLA), and nitrogen content (LN) of genus Oryza were investigated and their correlation was analyzed to assess some of the main photosynthetic traits among different species in the genus Oryza. The results revealed wide variation in these traits. The species O. rufipogon and O. australiensis exhibited maximum photosynthetic rate. Comparison of different types of genomes (diploid: 2n=2x=24; tetraploid: 2n=4x=48) and growth habit (shade- or sun-grown) showed the species of diploid (with genome symbol EE; 2n=2x=24) genomes, with...

Photosynthetic performance of Lycoris radiata var. radiata to shade treatments

S. B. Zhou, K. Liu, D. Zhang, Q. F. Li, G. P. Zhu

Photosynthetica 2010, 48(2):241-248 | DOI: 10.1007/s11099-010-0030-7

The effects of shade on the growth, leaf photosynthetic characteristics, and chlorophyll (Chl) fluorescence parameters of Lycoris radiata var. radiata were determined under differing irradiances (15, 65, and 100% of full irradiance) within pots. The HI plants exhibited a typical decline in net photosynthetic rate (P _N) during midday, which was not observed in MI- and LI plants. This indicated a possible photoinhibition in HI plants as the ratio of variable to maximum fluorescence (F_v/F_m) value was higher and the minimal fluorescence (F₀) was lower in the, and LI plants. Diurnal patterns...

Spatial and temporal variations in the photosynthesis-nitrogen relationship in a Japanese cedar (Cryptomeria japonica D. Don) canopy

H. Kobayashi, S. Inoue, K. Gyokusen

Photosynthetica 2010, 48(2):249-256 | DOI: 10.1007/s11099-010-0031-6

Spatial and temporal variations in light-saturated photosynthetic capacity and needle nitrogen (N) content were investigated in one 8 m tall Japanese cedar (Cryptomeria japonica D. Don) canopy for a full year. The photosynthetic capacity and needle N content in various layers of the canopy were measured every month. Temporal variations in photosynthetic capacity and needle N content expressed on a projected-area basis (P_area, N_area) were similar. Furthermore, both P_area and N_area decreased with increasing depth from the top of the canopy on each sampling date. As a consequence, a significant correlation...

Photosynthesis of Populus euphratica in relation to groundwater depths and high temperature in arid environment, northwest China

H. H. Zhou, Y. N. Chen, W. H. Li, Y. P. Chen

Photosynthetica 2010, 48(2):257-268 | DOI: 10.1007/s11099-010-0032-5

The photosynthetic characterization of Populus euphratica and their response to increasing groundwater depth and temperature were analyzed based on net photosynthetic rate (P _N), stomatal conductance (g _s), intercellular CO₂ concentration (C _i), transpiration rate (E), water use efficiency (WUE) and stomatal limitation (L_s) measured by a portable gas-exchange system (LI-6400) in the lower reaches of the Tarim River. Light-response curves were constructed to obtain light-compensation and light-saturation points (LCP and LSP), maximum photosynthetic rates...

Effects of realistically simulated, elevated UV irradiation on photosynthesis and pigment composition of the alpine snow alga Chlamydomonas nivalis and the arctic soil alga Tetracystis sp. (Chlorophyceae)

D. Remias, A. Albert, C. Lütz

Photosynthetica 2010, 48(2):269-277 | DOI: 10.1007/s11099-010-0033-4

An indoor sun simulator was used to provide elevated UV-B radiation (280-315 nm) in combination with realistic ratios to PAR (400-700 nm) and UV-A radiation (315-400 nm) in order to test the physiological response of a soil- and snow microalga during a three-day stress scenario, which may occasionally occur in their respective arctic and alpine habitats.Chlamydomonas nivalis and Tetracystis sp. are initial colonizers of harsh habitats like summer snow fields and bare arctic soils. The two species were chosen because of their role as primary successors in places where life is generally limited by extreme climatic and nutritional conditions.The...

Seed germination, seedling survival, and physiological response of sunflowers under saline and alkaline conditions

J. Liu, W. Q. Guo, D. C. Shi

Photosynthetica 2010, 48(2):278-286 | DOI: 10.1007/s11099-010-0034-3

Salinization and alkalization of soil are widespread environmental problem and the alkali stress is more destructive than the effects caused by salt stress. To compare the mechanism of salt and alkali stresses, a sunflower variety (Helianthus annuus L. cv. Baikuiza 6) was tested under saline or alkaline conditions by mixing two neutral salts (NaCl and Na₂SO₄) or two alkaline salts (NaHCO₃ and Na₂CO₃). The results showed that saline conditions differed greatly from alkaline conditions in their threshold intensities where sunflower can germinate, survive and grow. Under saline conditions,...

The short- and long-term response of Scrippsiella trochoidea (Pyrrophyta) to solar ultraviolet radiation

W. C. Guan, S. H. Lu

Photosynthetica 2010, 48(2):287-293 | DOI: 10.1007/s11099-010-0035-2

To assess the short- and long-term impacts of UV radiation (UVR, 280-400 nm) on the microalga Scrippsiella trochoidea, we exposed cells to three different radiation treatments (PAB: 280-700 nm, PA: 320-700 nm, and P: 400-700 nm). A significant decrease in the photochemical efficiency (Φ_PSII) at high irradiance (100% of incident solar radiation, 216.0 W m^-2) was observed. Photoinhibition was reduced from 62.7 to 10.9% when the cells were placed in 12% solar radiation (26.1 W m^-2). In long-term experiments (11 days) using batch cultures, cell densities during the first 5 days were decreased under treaments...

Photosynthetic performance of regenerated protoplasts from disintegrated cells of Bryopsis hypnoides (Chlorophyta)

F. Lü, G. C. Wang, J. F. Niu

Photosynthetica 2010, 48(2):294-301 | DOI: 10.1007/s11099-010-0036-1

The photosynthetic performances of regenerated protoplasts of Bryopsis hypnoides, which were incubated in seawater for 1, 6, 12, and 24 h, were studied using chlorophyll (Chl) fluorescence and oxygen measurements. Results showed that for the regenerated protoplasts, the pigment content, the ratios of photosynthetic rate to respiration rate, the maximal photosystem II (PSII) quantum yield (F_v/F_m), and the effective PSII quantum yield (Φ_PSII) decreased gradually along with the regeneration progress, indicated that during 24 h of regeneration there was a remarkable reduction in PSII activity of those newly formed...

Drought effect on photosynthetic activity, osmolyte accumulation and membrane integrity of two Cicer arietinum genotypes

M. C. Matos, P. S. Campos, J. A. Passarinho, J. N. Semedo, N. M. Marques, J. C. Ramalho, C. P. Ricardo

Photosynthetica 2010, 48(2):303-312 | DOI: 10.1007/s11099-010-0038-z

Drought was induced in chickpea (Cicer arietinum L.) genotypes (ChK 3226 and ILC 3279) differing in yield capacity. Water stress (S1, RWC around 55-50%; S2, RWC ≤ 40%) drastically reduced stomatal conductance (g _s) and net photosynthetic rate (P _N) in both genotypes. ILC 3279 showed greater photosynthetic capacity (A _max) decreases. Maximum PSII photochemical efficiency (F_v/F_m), photochemical quenching (q_P), total chlorophylls (Chls) and carotenoids (Cars) content showed stability in both genotypes under stress, but in S2 ILC 3279 presented an increase...

Allometric model for nondestructive leaf area estimation in clary sage (Salvia sclarea L.)

R. Kumar, S. Sharma

Photosynthetica 2010, 48(2):313-316 | DOI: 10.1007/s11099-010-0039-y

Leaf area estimation is an important biometrical observation recorded for evaluating plant growth in field and pot experiments. In this study, conducted in 2009, a leaf area estimation model was developed for aromatic crop clary sage (Salvia sclarea L.), using linear measurements of leaf length (L) and maximum width (W). Leaves from four genotypes of clary sage, collected at different stages, were used to develop the model. The actual leaf area (LA) and leaf dimensions were measured with a Laser Area meter. Different combinations of prediction equations were obtained from L, W, product of LW and dry mass of leaves (DM) to create linear (y =...

Chlorophyll fluorescence as a tool for evaluation of viability in freeze-stressed grapevine buds

L. Zulini, C. Fischer, M. Bertamini

Photosynthetica 2010, 48(2):317-319 | DOI: 10.1007/s11099-010-0040-5

This study examined the utility of the ratio of variable fluorescence to maximum fluorescence (F_v/F_m) to detect freezing injury on buds of two Vitis vinifera cultivars: Pinot noir and Pinot gris. Freezing treatments on buds caused a decrease both in F_v/F_m and percentage of budburst, more severely on Pinot gris than Pinot noir, specifically at the lower temperature (-20°C). F_v/F_m ratio showed a close correlation with percentage of budburst, and a threshold of the lethal F_v/F_m was proposed as an indicator of bud mortality.

Erratum to: Overaccumulation of glycine betaine enhances tolerance to drought and heat stress in wheat leaves in the protection of photosynthesis

G. P. Wang, X. Y. Zhang, F. Li, Y. Luo, W. Wang

Photosynthetica 2010, 48(2):302 | DOI: 10.1007/s11099-010-0037-0