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
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