Ca2+ has been considered as a necessary ion for alleviation of stress-induced damages in plants. We investigated effects of exogenous Ca2+ on waterlogging-induced damage to pepper and its underlying mechanisms. Pepper seedlings under stress were treated by spraying of 10 mM CaCl2. Applying exogenous Ca2+ increased the biomass of pepper leaves and roots, improved photosynthetic characteristics, membrane permeability, root activity, osmotic substance contents, antioxidant enzyme and alcohol dehydrogenase activities, while it reduced lactate dehydrogenase activity. It maintained hydroxide radical contents and activities of malate dehydrogenase and succinate dehydrogenase relatively high. Our results suggested that applying exogenous Ca2+ could regulate osmotic substance contents, antioxidant system activity, root respiration, and metabolism, and subsequently alleviate waterlogging-induced damages to pepper plants., B. Z. Yang, Z. B. Liu, S. D. Zhou, L. J. Ou, X. Z. Dai, Y. Q. Ma, Z. Q. Zhang, W. C. Chen, X. F. Li, C. L. Liang, S. Yang, X. X. Zou., and Obsahuje bibliografii
‘Hass‘ and ‘Fuerte‘ avocado plants were grown under well-watered or waterlogged conditions. Results indicated significant effects on the majority of the allometric parameters in waterlogged plants, with ‘Fuerte‘ displaying a more pronounced growth inhibition. Waterlogged conditions caused a progressive and simultaneous decline in net photosynthetic rate and stomatal conductance, earlier in ‘Fuerte‘ than in ‘Hass‘. Maximal potential quantum yield of PSII was unaffected by the soil water regime and/or variety and leaf water potential values in waterlogged plants were not more negative compared with control plants. ‘Fuerte‘ waterlogged plants exhibited increased contents of thiobarbituric acid reactive substances, whereas oxidative injury was not detected in ‘Hass‘. Finally, none of the two cultivars displayed valuable antioxidant potential, as evidenced by the decreased activities of the antioxidant enzymes superoxide dismutase, guaiacol peroxidase, glutathione peroxidase, and ascorbate peroxidase., G. Doupis, N. Kavroulakis, G. Psarras, I. E. Papadakis., and Obsahuje seznam literatury
This study aimed to investigate the effects of waterlogging on the growth and photosynthetic characteristics of paired near-isogenic lines of waterlogging-tolerant (Zz-R) and waterlogging-sensitive
(Zz-S) waxy corn inbred line seedlings. All plants were grown until the fifth leaves were fully expanded. Subsequently the plants in the pots were submerged in water for 4 d. During the waterlogging period, morphological and photosynthetic parameters related to waterlogging tolerance were examined. After 4 d, a significant decrease was observed in shoot and root fresh mass, net photosynthetic rate, stomatal conductance, transpiration, water-use efficiency, light-saturation point, maximal photosynthetic rate, apparent quantum yield, maximal quantum yield of PSII, and effective quantum yield of PSII photochemistry in waterlogged plants of both genotypes. The Zz-R genotype showed lesser reduction in all mentioned indices when compared to the Zz-S genotype. The inhibition of photosynthesis under waterlogging occurred due to the reduction in stomatal conductance, fluorescence parameters, and chlorophyll content. Thus, our study revealed that the Zz-R genotype can be a source of genetic diversity for important traits such as morphological and photosynthetic parameters., M. Zhu, F. H. Li, Z. S. Shi., and Obsahuje bibliografii
Soil moisture is the main limiting factor for vegetation growth at shell ridges in the Yellow River Delta of China. The objective of this study was to explore the soil moisture response of photosynthetic parameters and transpiration in Tamarix chinensis Lour., a dominant species of shell ridges. Leaf photosynthetic
light-response parameters and sap flow were measured across a gradient of relative soil water content (RWC), from drought (23%) to waterlogging (92%) conditions. Leaf photosynthetic efficiency and stem sap flow of T. chinensis showed a clear threshold response to soil moisture changes. Leaf net photosynthetic rate, water-use efficiency (WUE), light-saturation point, apparent quantum yield, maximum net photosynthetic rate, and dark respiration rate peaked at moderately high RWC, decreasing towards high and low values of RWC. However, peak or bottom RWC values substantially differed for various parameters. Excessively high or low RWC caused a significant reduction in the leaf photosynthetic capacity and WUE, while the high photosynthetic capacity and high WUE was obtained at RWC of 73%. With increasing waterlogging or drought stress, T. chinensis delayed the starting time for stem sap flow in the early morning and ended sap flow activity earlier during the day time in order to shorten a daily transpiration period and reduce the daily water consumption. The leaf photosynthetic capacity and WUE of T. chinensis were higher under drought stress than under waterlogging stress. Nevertheless, drought stress caused a larger reduction of daily water consumption compared to waterlogging, which was consistent with a higher drought tolerance and a poor tolerance to waterlogging in this species. This species was characterized by the low photosynthetic capacity and low WUE in the range of RWC between 44 and 92%. The RWC of 49-63% was the appropriate range of soil moisture for plant growth and efficient physiological water use of T. chinensis seedlings., J. B. Xia, Z. G. Zhao, J. K. Sun, J. T. Liu, Y. Y. Zhao., and Obsahuje bibliografii
One of the effective ways to address the effects of abnormal climate change on plant is to find germplasms that have better resistance to adverse environments. In this paper, we studied the responses of 5 pepper species Capsicum annuum L. (CA), C. baccatum L. (CB), C. chinense Jacquin. (CC), C. frutescens L. (CF) and C. pubescens Ruiz & Pavon (CP) as well as a wild pepper C. baccatum var. baccatum (CBY) to waterlogging stress. The results showed that warterlogging treatment greatly decreases photosynthetic pigment content, net photosynthetic rate (PN) and stomatal conductance (gs), and dramatically increases proline content and water-use efficiency (WUE) in all tested pepper, suggesting that pepper has weak resistance to waterlogging stress. The results also showed that changes of the above parameters vary in different species. CP had the smallest decreases in photosynthetic pigment content, PN, and gs and greatest increases in proline content and WUE. By contrast, CC had the greatest decreases in photosynthetic pigment content, P N, and gs and smallest increases in proline content and WUE, indicating that different species had different resistance to adverse environment and species CP and CC had the strongest and the weakest resistances, respectively. In addition, the study also demonstrated that wild pepper CBY had better resistance to adverse environment than all the tested species, indicating loss of the stress resistance genes during the process of domestication. Taking together, our study strongly suggests that pepper species should crossbreed with other species and wild pepper to expand genetic diversity, enlarge genetic distance, promote production, and improve the resistance to adverse environments. and L. J. Ou ... [et al.].