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232. Assessment of genotypic variation in salt tolerance of early CIMMYT hexaploid wheat germplasm using photosynthetic capacity and water relations as selection criteria
- Creator:
- Ashraf, M. and Shahbaz, M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- net photosynthetic rate, stomatal conductance, transpiration rate, and Triticum
- Language:
- Multiple languages
- Description:
- Twenty-five genotypes of early CIMMYT hexaploid wheat were screened for salt tolerance in a glasshouse experiment using photosynthetic capacity and water relation parameters as selection criteria. Under salt stress (150 mM NaCl) the genotypes Frontana, Norin-10, Mayo-54, Noreste-66, and Yaktana-54 excelled all other lines in shoot dry mass, and Na(20)TPP, Penjamo-62, Inia-66, Frontana, Siete Cerros, and Jaral-66 in grain yield per plant in both absolute and relative (percent of control) terms. Although net photosynthetic rate (PN) declined in all genotypes due to salt stress, it was not helpful in discriminating among genotypes according to salt tolerance. Similarly, no positive relationships of salt tolerance of the genotypes with stomatal conductance, leaf water potential, or turgor pressure were found. Every genotype used its own specific mechanism to tolerate salt stress. However, a large amount of variation in salt tolerance observed in 25 early CIMMYT wheat genotypes can be of considerable practical value for improving salt tolerance in the existing commercial hexaploid wheats. and M. Ashraf, M. Shahbaz.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
233. Assessment of photosynthetic potential of indoor plants under cold stress
- Creator:
- Gupta, S. M., Agarwal, A., Dev, B., Kumar, K., Prakash, O., Arya, M. C., and Nasim, M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, house plants, low-temperature stress, net photosynthetic rate, photosynthetic pigment, stomatal conductance, transpiration rate, water-use efficiency, 2, and 581
- Language:
- Multiple languages
- Description:
- Photosynthetic parameters including net photosynthetic rate (P N), transpiration rate (E), water-use efficiency (WUE), and stomatal conductance (g s) were studied in indoor C3 plants Philodendron domesticum (Pd), Dracaena fragans (Df), Peperomia obtussifolia (Po), Chlorophytum comosum (Cc), and in a CAM plant, Sansevieria trifasciata (St), exposed to various low temperatures (0, 5, 10, 15, 20, and 25°C). All studied plants survived up to 0°C, but only St and Cc endured, while other plants wilted, when the temperature increased back to room temperature (25°C). The P N declined rapidly with the decrease of temperature in all studied plants. St showed the maximum P N of 11.9 μmol m-2 s-1 at 25°C followed by Cc, Po, Pd, and Df. E also followed a trend almost similar to that of P N. St showed minimum E (0.1 mmol m-2 s-1) as compared to other studied C3 plants at 25°C. The E decreased up to ≈4-fold at 5 and 0°C. Furthermore, a considerable decline in WUE was observed under cold stress in all C3 plants, while St showed maximum WUE. Similarly, the g s also declined gradually with the decrease in the temperature in all plants. Among C3 plants, Pd and Po showed the maximum g s of 0.07 mol m-2 s-1 at 25°C followed by Df and Cc. However, St showed the minimum gs that further decreased up to -4-fold at 0°C. In addition, the content of photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] was varying in all studied plants at 0°C. Our findings clearly indicated the best photosynthetic potential of St compared to other studied plants. This species might be recommended for improving air quality in high-altitude closed environments., S. M. Gupta, A. Agarwal, B. Dev, K. Kumar, O. Prakash, M. C. Arya, M. Nasim., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
234. Assessment of salt tolerance in Populus alba clones using chlorophyll fluorescence
- Creator:
- Sixto, H., Aranda, I., and Grau, J. M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- disease index, photosystem 2, and salinity
- Language:
- Multiple languages
- Description:
- Cuttings of five Populus alba clones (S18 F1-26, Al29 F8-35, J3 F1-4, GU1 F16-36, PO9 F21-88), Populus euphratica, and Populus×euramericana (I-214) were submitted during 45 d to regular watering with NaCl solutions of electrical conductivity of 7 and 14 dS m-1. Chlorophyll a fluorescence in response to the salinity stress was assessed, using F0 and Fv/Fm. Differences in reaction to the salt were found in P. alba clones, F0 and Fv/Fm being the fluorescence parameters used to check out this stress. Minimal constant fluorescence of dark-adapted plants (F0) showed a better correlation with the disease index exhibited by plants and also with salinity dose than the parameter Fv/Fm. Some of the P. alba clones showed the same behaviour, assessed through fluorescence parameters, as P. euphratica, which was previously defined as salt tolerant, while the rest exhibited the same characteristics as I-214, which was very sensitive. and H. Sixto, I. Aranda, J. M. Grau.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
235. Assessment of tolerances in Mitragyna parvifolia (Roxb.) Korth. and Syzygium cumini Keels. seedlings to waterlogging
- Creator:
- Bidalia, A., Okram, Z., Hanief, M., and Rao, K. S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fluorescence chlorofylu a, výměna plynu, lenticely, adventitious roots, chlorophyll a fluorescence, gas exchange, lenticels, 2, and 581
- Language:
- Multiple languages
- Description:
- Waterlogging is one of the critical factors controlling the distribution, regeneration, and survival of vegetation in wetlands. Here, we tested the hypothesis that Mitragyna parvifolia (Roxb.) Korth. and Syzygium cumini Keels, inhabiting the Keoladeo National Park, a Ramsar wetland (Bharatpur, India), are tolerant to waterlogging. The morphological and photosynthetic variables of four-month-old seedlings subjected to waterlogging, along with the concentrations of macroand micronutrients, were examined. After 35 days, treatment was halted due to high mortality of S. cumini seedlings in contrast to that of M. parvifolia seedlings. Significant declines in most of the studied variables were observed in both species when compared with their respective controls. In addition, M. parvifolia seedlings developed adventitious roots and lenticels and showed an increased root biomass. Based on the results, we concluded that adaptive traits displayed by M. parvifolia seedlings facilitate its tolerance to waterlogging in contrast to S. cumini seedlings., A. Bidalia, Z. Okram, M. Hanief, K. S. Rao., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
236. Assimilation, translocation and accumulation of in two maize (Zea mays L.) hybrids of different drought tolerance
- Creator:
- Grzesiak, S., de Barbaro, A., and Filek, W.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- The effect of water stress on the gas exchange (CO2, H2O), distribution, water potential (T*), membrane permeability and chlorophyll content was studied in two maize hybrids, of the high and low drought tolerance, in the vegetative phase of growth. Diťferences in the responses to drought between both hybrids were clearly marked. After 5 d of drought the decrease in the net photosynthetic rate uptake and losses, transpiration rate (E) and increase of stomata resistance (r^ were greater in the drought-resistant hybrid than in the drought-susceptible one. On the contrary, after 10 or 15 d of drought, the decrease of and 'P in whole seedlings was greater in the susceptible hybrid than in the resistant one. Significant differences between hybrids were also observed in the accumulation of *'^C, the membrane permeability and the chlorophyll content. For all treatments the amount of carbon accumulation in roots of the resistant hybrid increased, while that of the susceptible one decreased. In the drought-resistant hybrid we observed a greater chlorophyll stability and a smaller damage of cell membranes than in the sensitive one.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
237. Atomic ratio of N to P influences the impact of UV irradiance on photosynthesis and growth in a marine dinoflagellate, Alexandrium tamarense
- Creator:
- Guan, W. C. and Li, L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- květy řas, efektivní fotochemická účinnost, algal bloom, effective photochemical efficiency, nutrient stoichiometry, solar ultraviolet radiation, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of the atomic ratio of N to P (N:P) on the response of Alexandrium tamarense to UV radiation (UVR) were investigated in this study. Artificial sea water of 5 different N:P ratios for indoor culture and with 3 different N:P ratios for outdoor culture were used for a period of 14 and 9 d, respectively. The short-term response of cells to UVR was analyzed using a fluorometer. Cells that acclimated to nutrient conditions at the Redfield value (16:1) showed the fastest growth rate and highest pigment concentrations in both indoor and outdoor conditions, compared to those acclimated to the non-Redfield conditions. Moreover, these physiological parameters were functions of the N:P ratio according to a two-order equation (y = a + bx + cx2, R2>0.95). The fluorescence data of indoor cultures showed that A. tamarense grown at 16:1 (N:P) exhibited the greatest ratio of repair rate/damage rate (r/k) and minimum level of UVR-induced inhibition. among those grown at all of the N:P ratios following UVR exposure. Outdoor cultures had the same patterns of fluorescence as indoor cultures, but the less UVR-induced inhibitions were detected compared the former with the latter. The following three parameters, the r/k, level of inhibition caused by the two radiation treatments following 60 min of exposure (PAR and PAB, respectively), and level of UVR-induced inhibition, were also functions of the N:P ratio according to the two-order equation (R2>0.96). Further, there was a negative correlation between UVR-induced inhibition and the r/k ratio. In summary, the Redfield value (16:1) was the optimal nutrient stoichiometry for the protection of A. tamarense against the deleterious effects of UVR. Results were not impacted by previous light history experienced by cells., W. C. Guan, L. Li., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
238. ATP-sulfurylase activity, photosynthesis, and shoot dry mass of mustard (Brassica juncea L.) cultivars differing in sulfur accumulation capacity
- Creator:
- Nazar, R., Khan, N. A., and Anjum, N. A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dry mass, leaf area, nitrogen content, and sulfate transport index
- Language:
- Multiple languages
- Description:
- Sulfur (S) is an essential nutrient element required in a large quantity by mustard. S regulates photosynthesis and plant growth through improving nitrogen (N) acquisition. Mustard cultivars Alankar, Varuna, Pusa Jai Kisan, and SS2 differing in S accumulation capacity calculated as sulfate transport index (STI) were tested for ATP-sulfurylase activity, S and N accumulation, photosynthesis, and shoot dry mass (DM) at 30 and 60 d after sowing (DAS). The activity of ATP-sulfurylase, shoot N content, net photosynthetic rate (PN), leaf area, and shoot DM of the cultivars were in the order: Pusa Jai Kisan>Alankar>Varuna>SS2. ATP-sulfurylase activity was strongly and positively correlated with PN and shoot DM in all the cultivars. Hence ATP-sulfurylase activity may be used as a physiological trait for augmenting photosynthesis and shoot DM. and R. Nazar, N. A. Khan, N. A. Anjum.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
239. Author index
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Multiple languages
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
240. Author index
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Multiple languages
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public