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2612. Gas exchange characteristics of the flue-cured tobacco (Nicotiana tabacum L.) cultivars grown under two production systems
- Creator:
- Srinivas, P., Smith, B. N., and Swamy, P. M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- intercelullar CO2 concentration, leaf biomass, net photosynthetic rate, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- The net photosynthetic rate (PN), intercellular CO2 concentration (Ci), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), and leaf biomass production of four American flue-cured tobacco (Nicotiana tabacum L.) cultivars K 326, K 358, and Speight G 28 were compared with three local Indian cultivars 16/103, Special FCV, and PCT-7, during 1994 and 1995 crop seasons under irrigated and rainfed production systems (Northern light soils, NLS, and Karnataka light soils, KLS) in India. By comparison, the American tobacco cv. K 326 showed the highest PN and gs. A positive correlation was found between PN and biomass production in all the varieties tested (r = 0.55 in NLS and 0.73 in KLS). The American cultivars were superior than the local cultivars in their biomass production and PN under Indian farming conditions. and P. Srinivas, B. N. Smith, P. M. Swamy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2613. Gas exchange in lisianthus plants (Eustoma grandiflorum) submitted to different doses of nitrogen
- Creator:
- Marchese, J. A., Katz, I., Sousa, A. P., and Rodrigues, J. D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, mineral nutrition, photosynthesis, stomatal conductance, and transpiration
- Language:
- Multiple languages
- Description:
- The effect of different doses of nitrogen (N) on gas exchange, relative chlorophyll (Chl) amount, and the content of N in the aerial biomass of lisianthus was evaluated. The treatments consisted of six different concentrations of N (50, 100, 150, 200, 250, and 300 g m-3 noted as N50, N100, N150, N200, N250, and N300, respectively), applied through the fertirrigation technique. N250 and N300 induced increase in the contents of foliar Chl and N in the aerial biomass, that in turn contributed to an increase of photosynthetic activity in lisianthus. and J. A. Marchese ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2614. Gas exchange in olive fruit
- Creator:
- Proietti, P., Famiani, F., and Tombesi, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, fruit growth, gross photosynthetic rate, irradiance response curve, Olea europaea L., olive oil, respiration rate, saccharides, stomatal conductance, and transpiration rate
- Language:
- Multiple languages
- Description:
- Dry matter (DM) of olive fruit (cv. Leccino) constantly increased from fruit-set (mid-June) to the end of October. The oil content increased rapidly from the beginning of August, about 40-50 d after full bloom (AFB), to the end of October. As the oil content increased, the saccharide content decreased. On a DM basis, fruit dark respiration rate (RD) and stomatal conductance (Gs) were high soon after fruit-set, then strongly decreased. Gross photosynthetic rate (PG) in full sunlight was high in the first 3 weeks after fruit-set, when the chlorophyll (Chl) content and the ratio between fruit surface area and volume were high, then it progressively decreased. The fruit intercellular CO2 concentration (Ci) was always relatively high, particularly from September onwards. The PG increased following the increase of irradiance (I). The daily PG trend was similar to the I and temperature trends, showing the maximum values at 14:00 h. For a large part of the fruit growing period, during daylight, the CO2 intake by a fruit permitted the reassimilation of a large part (40-80%) of the CO2 produced by RD. The stomata in the first stages of fruit growth were oval and surrounded by guard cells, two months later they lost their shape and were covered by wax. The reduction in fruit PG during fruit growth could be connected to the reduction of the ratio between fruit surface area and fruit volume and the cellular differentiation, whereas the constant high Ci seems to exclude the influence of Gs decrease. Even if olive fruit is highly heterotrophic organ, its photosynthesis can considerably reduce the use of assimilates for respiration and favour fruit maintenance and growth. and P. Proietti, F. Famiani, A. Tombesi.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2615. Gas exchange in senescing leaves of Olea europaea L.
- Creator:
- Proietti, P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, detachment force, nitrogen content, olive, respiration rate, saccharides, stomatal conductance, and transpiration rate
- Language:
- Multiple languages
- Description:
- From the beginning of olive leaf yellowing to leaf fall (1/3 months), there was a general trend from anabolism to catabolism. Rates of net photosynthesis (PN) and respiration, areal dry mass, and contents of pigments, particularly of chlorophyll (Chl) a, starch, and above all nitrogen (N) decreased. The detachment force decreased dramatically only in completely chlorotic leaves. Chl a : b ratio only declined in the last 10-20 d of senescence, when the total Chl contents diminished by about 70 %, after which the N content, PN, and efficiency of the photochemical energy conversion of the remaining Chl and N dramatically declined. Consequently, for most of the natural course of senescence PN remained relatively high. The reduction in PN was associated with the decreases in transpiration rate (E) and stomatal conductance (gs), but these probably did not cause the decline of PN. The recycling of saccharide compounds was low, while 50 % of the total N on a leaf area basis was relocated back before leaf abscission, changing the leaf from a carbon source to a mineral source. Therefore, considering that senescing leaves in olive trees contribute to carbon gain and allow the recycling of resources, it is essential to prevent the premature leaf abscission by avoiding deficits of water and mineral nutrients and by using pruning and training systems that allow good irradiation of all leaves in the crown.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2616. Gas exchange of carrot leaves in response to elevated CO2 concentration
- Creator:
- Kyei-Boahen, S., Astatkie, T., Lada, R., Gordon, R., and Caldwell, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- CO2 compensation concentration, cultivar differences, Daucus carota, net photosynthetic rate, nonlinear regression model, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- Short-term responses of four carrot (Daucus carota) cultivars: Cascade, Caro Choice (CC), Oranza, and Red Core Chantenay (RCC) to CO2 concentrations (Ca) were studied in a controlled environment. Leaf net photosynthetic rate (PN), intercellular CO2 (Ci), stomatal conductance (gs), and transpiration rate (E) were measured at Ca from 50 to 1 050 μmol mol-1. The cultivars responded similarly to Ca and did not differ in all the variables measured. The PN increased with Ca until saturation at 650 μmol mol-1 (Ci= 350-400 μmol mol-1), thereafter PN increased slightly. On average, increasing Ca from 350 to 650 and from 350 to 1 050 μmol mol-1 increased PN by 43 and 52 %, respectively. The PNvs.Ci curves were fitted to a non-rectangular hyperbola model. The cultivars did not differ in the parameters estimated from the model. Carboxylation efficiencies ranged from 68 to 91 μmol m-2 s-1 and maximum PN were 15.50, 13.52, 13.31, and 14.96 μmol m-2 s-1 for Cascade, CC, Oranza, and RCC, respectively. Dark respiration rate varied from 2.80 μmol m-2 s-1 for Oranza to 3.96 μmol m-2 s-1 for Cascade and the CO2 compensation concentration was between 42 and 46 μmol mol-1. The gs and E increased to a peak at Ca= 350 μmol mol-1 and then decreased by 17 and 15 %, respectively when Ca was increased to 650 μmol mol-1. An increase from 350 to 1 050 μmol mol-1 reduced gs and E by 53 and 47 %, respectively. Changes in gs and PN maintained the Ci:Ca ratio. The water use efficiency increased linearly with Ca due to increases in PN in addition to the decline in E at high Ca. Hence CO2 enrichment increases PN and decreases gs, and can improve carrot productivity and water conservation. and S. Kyei-Boahen ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2617. Gas exchange of different spring cereal genotypes under normál and drought conditions
- Creator:
- Loboda, T.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Influence of soil drought (40 d) on gas exchange of 10 cultivars of spring cereals (wheat, barley, triticaie and oats) grown in growth chamber was studied. When soil water content was decreased from 60 to 35 % of Ml water capacity, a new steady levels of net photosynthetic rate, transpiration rate and stomatal conductance (about twice, 3-4 and 2-3 fold lower, respectively) were observed after 3 d for both studied oat cultivars and after 5 d for others. These levels were maintained almost the same till the end of the experiment. Calculated water use efficiency (WUE) of water stressed plants increased 3-4 fold, the highest being for barley while the lowest for Oats. At die beginning of the night dark respiration of well watered plants was a little higher than that of water stressed plants but at the end of ihe night was the Sáme independently of water treatment, aithough 20-30 % lower than at the begitming of the night.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2618. Gas exchange of in vitro and ex vitro grown grapevine plants
- Creator:
- Slavtcheva, T. and Dimitrova, V.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- acclimation, dark respiration rate, fresh mass, leaf area, net photosynthetic rate, shoot and root lengths, shoot node number, transpiration rate, and Vitis vinifera L.
- Language:
- Multiple languages
- Description:
- Net photosynthetic rate (PN) and dark respiration rate (RD) were measured in Vitis vinifera L. cvs. Dimiat 4/24 (23rd subculture), Dimiat 4/38 (22nd subculture), and Italian Riesling 3/47 (22nd subculture) on days 3, 2, and 1 (1st series) before transfer from the in vitro culture and on days 14, 15, 16 (2nd series) and 28, 29, 30 (3rd series) after the transfer. PN of in vitro and ex vitro plants was strongly affected by irradiance. PN and RD of in vitro plantlets were lower and transpiration rate (E) was higher compared to those of ex vitro plantlets. PN, RD, and E changed in the course of acclimation. and T. Slavtcheva, V. Dimitrova.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2619. Gas exchange of spring barley and wheat grown under mild water shortage
- Creator:
- Łoboda, T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Hordeum, intercellular CO2 concentration, photosynthesis, stomatal conductance, and Triticum
- Language:
- Multiple languages
- Description:
- During mild water stress (decrease of full water capacity from 60 to 35 %) net photosynthetic rate (PN) of four spring barley and wheat genotypes was about twice lower than that for unstressed plants and was mainly limited by non-stomatal factors. Availability of CO2 from intercellular spaces did not change significantly when stomatal conductance (gs) decreased from 0.25-0.35 to 0.15-0.20 mol(H2O) m-2 s-1. There may be two main processes leading to similar intercellular CO2 concentration (ci) in stressed and unstressed seedlings despite of twice lower PN under mild water stress: (a) lower diffusion of CO2 through stomata represented by lower gs, (b) lower consumption of CO2 by photosynthetic apparatus of stressed plants. Last factor is partially pronounced by lower response of PN to ci observed for stressed than for control plants.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2620. Gas exchange of terrestrial and epiphytic orchids from Brazilian Atlantic Rainforest
- Creator:
- Pires, M. V., Almeida, A.-A. F., Santos, E. A., and Bertolde, F. Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, epiphytes, net photosynthetic rate, orchids, photosynthesis, stomatal conductance, terrestrial, transpiration, 2, and 58
- Language:
- Multiple languages
- Description:
- Leaf gas exchange of terrestrial and epiphytic orchids from the Atlantic Rainforest in northeast Brazil was investigated under artificial growth conditions. The terrestrial orchids showed higher values of all photosynthetic parameters in comparison to epiphytic ones. There was a close relationship between PN and gs for both terrestrial and epiphytic orchids. Taken together, our results demonstrated that the photosynthetic parameters were related to the specific growth habits of the orchids under study., M. V. Pires ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public