The objective of this study was to investigate a response to low-light environments in hybrids and commercial cultivars of Boehmeria nivea L. Two hybrids (Chuanzhu 11 and Chuanzhu 8) and two commercial cultivars (Chuanzhu 12 and Chuanzhu 6) of ramie were subjected to a shade treatment for 6, 12, and 18 days. The shade treatment led to a significant decrease in some plant traits and fiber yield in four ramie cultivars, whereas their leaf area and plant height increased. In addition, net photosynthesis and stomatal conductance significantly declined in response to shade, while transpiration rate and intercellular CO2 did not significantly change. Moreover, chlorophyll (Chl) and carotenoid (Car) concentration, Chl/Car, and Chl (a+b) per leaf dry mass significantly increased in the response to shade, while the Chl a/b ratio decreased. Furthermore, Chuanzhu 6 and Chuanzhu 11 were more tolerant to shade than Chuanzhu 12 and Chuanzhu 8, thus, they could be potentially used for management practices and breeding programs., C.-J. Huang, G. Wei, Y.-C. Jie, J.-J. Xu, S. A. Anjum, M. Tanveer., and Seznam literatury
Pepper is a thermophilous and heliophilic vegetable. In China, pepper is grown in greenhouse during winter and spring under lower temperature and irradiation. In this study, we investigated the effects of low temperature and low irradiance (LTLI) on the physiological characteristics and the expression of related genes in five pepper species, Capsicum annuum L. (CA), C. baccatum L. (CB), C. chinense Jacquin (CC), C. frutescens L. (CF), and C. pubescens Ruiz & Pavon (CP) in order to screen for greenhouse species that is resistant to such adverse conditions. We observed significant reductions not only in photosynthetic pigments and stomatal conductance but also in proline, total soluble sugar, enzyme activity, and root activity; disordered arrangements of leaf palisade and spongy tissues; and first rising and then falling expression of C-repeat binding factor (CBF3) and cold-regulated genes (CORc410). These results indicate that pepper is not resistant to LTLI. We also found that CP showed significantly higher photosynthetic activity, more proline and total soluble sugar, higher enzyme activity, higher root activity, higher CBF3 and CORc410 expression levels, more tightly packed leaf palisade and spongy tissues, and thicker bundle sheath than the other four species did under LTLI, while CF exhibited the lowest values for these indicators. It demonstrated significant differences in the ability to resist to LTLI among different species, with CP showing the strongest resistance, followed by CB. Therefore, we recommend the introduction of CP and CB to greenhouse cultivation to further screen for low temperature and low light-resistant pepper varieties to increase pepper production by strengthening intervariety hybridization., L. J. Ou, G. Wei, Z.Q. Zhang, X. Z. Dai, X. X. Zou., and Obsahuje bibliografii
Ramie (Boehmeria nivea L.) is an important crop that serves as fine fiber material, high protein feedstuff, and valuable herbal medicine in China. However, increasing salinity in soil limits the productivity. We investigated in a greenhouse experiment responses to salinity in two ramie cultivars, Chuanzhu-12 (salt-tolerant cultivar, ST) and Xiangzhu-2 (salt-sensitive cultivar, SS), to elucidate the salt tolerance mechanism of this species. Salinity stress substantially reduced both chlorophyll and carotenoid contents. In addition, net photosynthesis, transpiration rate, stomatal conductance, intercellular CO2 concentration, and the ratio of intercellular CO2 to ambient CO2 were affected, less in ST. Nevertheless, salinity stress markedly improved water use efficiency and intrinsic water use efficiency in both species. Moreover, relative water contents, soluble proteins, and catalase activity were substantially impaired, while proline accumulation and superoxide dismutase activity were enhanced substantially, more in ST. Furthermore, noteworthy increase in peroxidase activity and decrease in malondialdehyde content was recorded in ST, whereas, in SS, these attributes changed conversely. Overall, the cultivar ST exhibited salt tolerance due to its higher photosynthetic capacity, chlorophyll content, antioxidative enzyme activity, and nonenzymatic antioxidants, as well as reduced lipid peroxidation and maintenance of the tissue water content. This revealed the salt tolerance mechanism of ramie plants for adaptation to salt affected soil., C.-J. Huang, G. Wei, Y.-C. Jie , J.-J. Xu, S.-Y. Zhao, L.-C. Wang, S. A. Anjum., and Obsahuje seznam literatury