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Start Over Subject botanika Date Unknown

1. „Dívej se, abys viděl.” Rozhovor s Jarmilou Kubíkovou u příležitosti jejích osmdesátin

Creator:
Pavel Špryňar
Format:
print
Type:
article, jubilejní články, festschriften, model:article, and TEXT
Subject:
Přírodní vědy. Matematické vědy, Kubíková, Jarmila, 1933-, botanika, ekologie rostlin, ochrana přírody, rozhovor, botany, plant ecology, nature conservation, interview, 6, and 5
Language:
Czech
Description:
Pavel Špryňar.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. „Malování” rostlinných chromozomů

Creator:
Mandáková, Terezie
Format:
print
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Botanika, botanika, brukvovité, chromozomy, botany, Brassicaceae, chromosomes, 2, and 58
Language:
Czech
Description:
Čeleď brukvovitých patří k největším rostlinným čeledím; zahrnuje 49 tribů, 321 rodů a 3 660 druhů. Zájem vědců o tuto rostlinnou skupinu vzrostl především díky ustanovení huseníčku rolního (Arabidopsis thaliana) modelovým druhem a sekvenování jeho genomu. To v r. 2000 odstartovalo mimo jiné bouřlivý rozvoj srovnávací fylogenomiky a cytogenomiky, včetně úspěšného zavedení metody malování chromozomů (chromosome painting) huseníčku a její aplikace na další zástupce brukvovitých (srovnávací malování chromozomů; comparative chromosome painting, CCP). Metoda CCP umožňuje studium chromozomové kolinearity, rozpoznání chromozomových přestaveb, porovnání struktury chromosomů nebo jejich částí mezi jednotlivými druhy a rekonstrukci struktury celých karyotypů. Brukvovité jsou jedinou rostlinnou čeledí, u níž je v tomto rozsahu metoda CCP použitelná. Srovnávací cytogenetické mapy brukvovitých tak představují zcela unikátní typ dat o evoluci rostlinných karyotypů a genomů., Whole-genome sequencing of the model plant Arabidopsis thaliana has stimulated a rapid development of comparative phylogenomics and cytogenomics, including the invention of chromosome painting in A. thaliana and comparative chromosome painting (CCP) in other species of the Brassicaceae (Cruciferae) family. This is the only plant family in which large-scale CCP is feasible. CCP provides unique insights into the karyotype and genome evolution in plants by comparing chromosome collinearity, identification of chromosome rearrangements, construction of comparative cytogenetic maps, and reconstruction of ancestral karyotype structures., and Terezie Mandáková.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. 28-homobrassinolide improves growth and photosynthesis in Cucumis sativus L. through an enhanced antioxidant system in the presence of chilling stress

Creator:
Fariduddin, Q., Yusuf, M., Chalkoo, S., Hayat, S., and Ahmad, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, antioxidant enzymes, brassinosteroids, chilling stress, chlorophyll fluorescence, Cucumis sativus, and photosynthesis
Language:
Multiple languages
Description:
The ameliorative role of 28-homobrassinolide under chilling stress in various growth, photosynthesis, enzymes and biochemical parameters of cucumber (Cucumis sativus L.) were investigated. Cucumber seedlings were sprayed with 0 (control), 10-8, or 10-6 M of 28-homobrassinolide at the 30-day stage. 48 h after treatment plants were exposed for 18 h to chilling temperature (10/8°C, 5/3°C). The most evident effect of chilling stress was the marked reduction in plant growth, chlorophyll (Chl) content, and net photosynthetic rate, efficiency of photosystem II and activities of nitrate reductase and carbonic anhydrase. Moreover, the activities of antioxidant enzymes; catalase (E.C. 1.11.1.6), peroxidase (E.C.1.11.1.7), superoxide dismutase (E.C. 1.15.1.1) along with the proline content in leaves of the cucumber seedlings increased in proportion to chilling temperature. The stressed seedlings of cucumber pretreated with 28-homobrassinolide maintained a higher value of antioxidant enzymes and proline content over the control suggesting the protective mechanism against the ill-effect caused by chilling stress might be operative through an improved antioxidant system. Furthermore, the protective role of 28-homobrassinolide was reflected in improved growth, water relations, photosynthesis and maximum quantum yield of photosystem II both in the presence and absence of chilling stress. and Q. Fariduddin ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. 50 let od založení Ústavu experimentální botaniky Akademie věd

Creator:
Jan Krekule
Format:
print
Type:
article, jubilejní články, festschriften, model:article, and TEXT
Subject:
Botanika, Blattný, Ctibor, 1928-2008, Němec, Bohumil, 1873-1966, Ústav experimentální botaniky (Československá akademie věd), botanika, fytopatologie, genetika rostlin, botany, phytopathology, plant genetics, 2, and 58
Language:
Czech
Description:
Jan Krekule.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. A comparative analysis of photosynthetic characteristics of hulless barley at two altitudes on the Tibetan Plateau

Creator:
Fan, Y. Z., Zhong, Z. M., and Zhang, X. Z.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, altitude, apparent quantum efficiency, maximum net photosynthesis, and Tibetan Plateau
Language:
Multiple languages
Description:
To determine the photosynthetic characteristics of C3 plants and their sensitivity to CO2 at different altitudes on the Tibetan Plateau, hulless barley (Hordeum vulgare L. ssp. vulgare) was grown at altitudes of 4,333 m and 3,688 m. Using gas-exchange measurements, photosynthetic parameters were simulated, including the maximum net photosynthesis (Pmax) and the apparent quantum efficiency (α). Plants growing at higher altitude had higher net photosynthetic rates (PN), photosynthesis parameters (Pmax and α) and sensitivities to CO2 enhancement than plants growing at lower altitude on the Tibetan Plateau. The enhancements of PN, Pmax, and α for plants growing at higher altitude, corresponding with 10 μmol(CO2) mol-1 increments, were approximately 0.20∼0.45%, 0.05∼0.20% and 0.12∼0.36% greater, respectively, than for plants growing at lower altitude, respectively, where CO2 levels rose from 10 to 170 μmol(CO2) mol-1. Therefore, on the Tibetan Plateau, the changes in the photosynthetic capacities and the photosynthetic sensitivities to CO2 observed in the C3 plants grown above 3,688 m are likely to increase with altitude despite the decreasing CO2 partial pressure. and Y. Z. Fan ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. A comparison between yellow-green and green cultivars of four vegetable species in pigments, ascorbate, photosynthesis, energy dissipation, and photoinhibition

Creator:
Weng, J.-H., Chien, L.-F., Jiang, C.-Y., Shih, F.-C., and Chen, H.-Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, Amaranthus tricolor, ascorbate-deficient, Brassica oleracea var. alboglabra, Brassica rapa, chlorophyll-deficient, energy dissipation, Ipomoea batatas, photoinhibition, and photosynthesis
Language:
Multiple languages
Description:
Yellow-green foliage cultivars of four vegetables grown outdoors, i.e., Chinese mustard (Brassica rapa), Chinese kale (Brassica oleracea var. alboglabra), sweet potato (Ipomoea batatas) and Chinese amaranth (Amaranthus tricolor), had lower chlorophyll (Chl) (a+b) (29-36% of green cultivars of the same species), total carotenoids (46-62%) and ascorbate (72-90%) contents per leaf area. Furthermore, yellow-green cultivars had smaller photosystem II (PSII) antenna size (65-70%) and lower photosynthetic capacity (52-63%), but higher Chl a/b (107-156%) and from low (60%) to high (129%) ratios of de-epoxidized xanthophyll cycle pigments per Chl a content. Potential quantum efficiency of PSII (Fv/Fm) of all overnight dark-adapted leaves was ca. 0.8, with no significant difference between yellow-green and green cultivars of the same species. However, yellow-green cultivars displayed a higher degree of photoinhibition (lower Fv/Fm after illumination) when they were exposed to high irradiance. Although vegetables used in this study are of either temperate or tropical origin and include both C3 and C4 plants, data from all cultivars combined revealed that Fv/Fm after illumination still showed a significant positive linear regression with xanthophyll cycledependent energy quenching (qE) and a negative linear regression with photoinhibitory quenching (qI). Fv/Fm was, however, not correlated with nonphotochemical quenching (NPQ). Yet, a higher degree of photoinhibition in yellow-green cultivars could recover during the night darkness period, suggesting that the repair of PSII in yellow-green cultivars would allow them to grow normally in the field. and J.-H. Weng ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. A mathematical model for describing light-response curves in Nicotiana tabacum L.

Creator:
Chen, Z. Y., Peng, Z. S., Yang, J., Chen, W. Y., and Ou-Yang, Z. M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, light-response curves, light saturation point, maximum net photosynthetic rate, modified exponential model, net photosynthetic rate, and Nicotiniana tabacum L.
Language:
Multiple languages
Description:
A modified exponential model was used to describe light-response curves of Nicotiana tabacum L. The accuracies of an exponential model, a nonrectangular hyperbola model, a rectangular hyperbola model, a modified rectangular hyperbola model and the modified exponential model were evaluated by Mean square error (MSE) and Mean absolute error (MAE). The tests MSE and MAE of the modified exponential model were the lowest among the five models. The light saturation point (LSP) obtained by the exponential model, the nonrectangular hyperbola model and the rectangular hyperbola model were much lower than the measured values, and the maximum net photosynthetic rates (Pmax) calculated from these models, were greater than the measured values. Pmax at LSP of 1,077 μmol m-2 s-1 calculated by the modified exponential model was 12.34 μmol(CO2) m-2 s-1, which was more accurate than the values obtained from the modified rectangular hyperbola model. The results show that the modified exponential model is superior to other models for describing light-response curves. and Z. Y. Chen ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

9. A newly developed SGB buffer greatly enhances energy transfer efficiency from phycobilisomes to photosystem II in cyanobacteria in vitro

Creator:
Chen, L. P., Wang, Q. X., and Ma, W. M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, energy transfer efficiency, photosystem II, phycobilisome, SGB buffer, Synechocystis sp. PCC 6803, thylakoid membrane, 2, and 58
Language:
Multiple languages
Description:
The transfer of light energy from phycobilisomes (PBS) to photosystem II (PSII) reaction centers is vital for photosynthesis in cyanobacteria and red algae. To investigate the relationship between PBS and PSII and to optimize the energy transfer efficiency from PBS to PSII, isolation of the PBS-PSII supercomplex is necessary. SPC (sucrose/phosphate/citrate) is a conventional buffer for isolating PBS-PSII supercomplex in cyanobacteria. However, the energy transfer occurring in the supercomplex is poor. Here, we developed a new buffer named SGB by adding 1M glycinebetaine and additional sucrose to SPC buffer. Compared to SPC, the newly developed SGB buffer greatly enhanced the associated populations of PBS with thylakoid membranes and PSII and further improved the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro. Therefore, we conclude that SGB is an excellent buffer for isolating the PBS-PSII supercomplex and for enhancing the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro., L. P. Chen, Q. X. Wang, W. M. Ma., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. A simple model for nondestructive leaf area estimation in bedding plants

Creator:
Giuffrida, F., Rouphael, Y., Toscano, S., Scuderi, D., Romano, D., Rivera, C. M., Colla, G., and Leonardi, C.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, calibration, leaf area, models, regression analysis, and validation
Language:
Multiple languages
Description:
Measurement of leaf area is commonly used in many horticultural research experiments, but it is generally destructive, requiring leaves to be removed for measurement. Determining the individual leaf area (LA) of bedding plants like pot marigold (Calendula officinalis L.), dahlia (Dahlia pinnata), sweet William (Dianthus barbatus L.), geranium (Pelargonium × hortorum), petunia (Petunia × hybrida), and pansy (Viola wittrockiana) involves measurements of leaf parameters such as length (L) and width (W) or some combinations of these parameters. Two experiments were carried out during spring 2010 (on two pot marigold, four dahlia, three sweet William, four geranium, three petunia, and three pansy cultivars) and summer 2010 (on one cultivar per species) under greenhouse conditions to test whether a model could be developed to estimate LA of bedding plants across cultivars. Regression analysis of LA versus L and W revealed several models that could be used for estimating the area of individual bedding plants leaves. A linear model having LW as the independent variable provided the most accurate estimate (highest R2, smallest mean square error, and the smallest predicted residual error sum of squares) of LA in all bedding plants. Validation of the model having LW of leaves measured in the summer 2010 experiment coming from other cultivars of bedding plants showed that the correlation between calculated and measured bedding plants leaf areas was very high. Therefore, these allometric models could be considered simple and useful tools in many experimental comparisons without the use of any expensive instruments. and F. Giuffrida ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public