Genotypic Diversity of Cross-Tolerance to Oxidative and Drought Stresses in Rice Seedlings Evaluated by the Maximum Quantum Yield of Photosystem II and Membrane Stability

The aim of the research work was to evaluate phytotoxicity of mesotrione in poppy (Papaver somniferum). The amount of spraying water (150, 300 and 450 l per hectare) was compared as well. In the end, the different growth stimulators (Atonik – 0.6 l . ha−1, Route – 0.8 l . ha−1) and the adjuvants (Atplus 463 – 0.5% solution, Silwet 77 – 0.1 l . ha−1) wre tested. Degree of phytotoxicity of individual variants was assessed by measuring chlorophyll fluorescence (parameter: maximum quantum yield of electron transport in photosystem II - QY) in 1st to 21st day after treatment. The results showed that the application of mesotrione caused phytotoxicity on poppy plants. The most significant phytotoxicity is evident at doses of 450 l spraying water per hectare. Addition of growth stimulators and adjuvants increases the phytotoxicity (decreases the value of QY) compared to the herbicide application itself. The mesotrione reduced the weight of dry plants by 15 % (150 l of spraying water), 1 % (300 l of spraying water) and 64 % (450 l of spraying water) compared to control variant.

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Kärin Nickelsen and Govindjee: The Maximum Quantum Yield Controversy: Otto Warburg and the “Midwest-Gang”

Photosynthesis Research ◽

10.1007/s11120-011-9705-6 ◽

2011 ◽

Vol 110 (2) ◽

pp. 139-141

Author(s):

Howard Gest

Keyword(s):

Quantum Yield ◽

Maximum Quantum Yield ◽

Otto Warburg

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Nitrogen and Phosphorus Addition to Soil Improves Seed Yield, Foliar Stomatal Conductance, and the Photosynthetic Response of Rapeseed (Brassica napus L.)

Agriculture ◽

10.3390/agriculture11060483 ◽

2021 ◽

Vol 11 (6) ◽

pp. 483

Author(s):

Esmaeil Zangani ◽

Kamran Afsahi ◽

Farid Shekari ◽

Eileen Mac Sweeney ◽

Andrea Mastinu

Keyword(s):

Stomatal Conductance ◽

Quantum Yield ◽

Photosystem Ii ◽

Chlorophyll Content ◽

Seed Yield ◽

Nitrogen Application ◽

Flowering Stage ◽

Nitrogen And Phosphorus ◽

Brassica Napus L ◽

Phosphorus Levels

The effects of nitrogen and phosphorus levels on the physiological traits, yield, and seed yield of rapeseed (Brassica napus L.), were studied in a farm research project of Zanjan University. Three levels of nitrogen (0, 100, and 200 kg/ha) and three levels of phosphorus (0, 75, and 150 kg/ha) were considered. The results showed that an increase in nitrogen level caused an increase in the leaf chlorophyll content so that the application of 200 kg/ha of nitrogen increased the chlorophyll content of the leaves until the mid-grain filling stage. Nitrogen application lowered leaf stomatal conductance in the early flowering stage whereas the stomatal conductance was increased during the late flowering stage. Nitrogen application (100 and 200 kg/ha) also increased the quantum yield of photosystem II. On the other hand, with the application of 150 kg/ha and 75 kg/ha of phosphorus, the leaf stomatal conductance and the quantum yield of photosystem II in the early flowering stage increased respectively. The results showed that the application of 200 kg/ha of nitrogen and 75 kg/ha of phosphorus significantly increased seed and oil yield compared to the control. In addition, the number of siliques per plant and the weight of 1000 seeds showed an increasing trend that was affected by nitrogen and phosphorus levels. This study demonstrated that nitrogen enhanced the chlorophyll content, leaf area, and consequently, the quantum yield of photosystem II. Nitrogen also augmented the seed filling duration, seed yield, and oil yield by increasing gas exchange. As a result, the application of 100 kg/ha of nitrogen together with 75 kg/ha phosphorus showed the greatest effect on the qualitative and quantitative yield of rapeseed. However, the application of 200 kg/ha of nitrogen alone or in combination with different levels of phosphorus did not significantly increase many of the studied traits.

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