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
Příspěvek je věnován problematice bezdomovců a žebráků. Podává základní informace o této sociální kategorii lidí zjevně chudých, žijících na okraji majoritní společnosti a vyznačujících se svým specifickým způsobem života. Jen dobře informovaný člověk je schopný pochopit složitou problematiku vzájemné tolerance a rovnosti všech lidí bez biologických a kulturních rozdílů (projevy rasismu, náboženské nesnášenlivosti, xenofobie a intolerance), včetně nezbytné péče o zdravotně postižené a sociálně znevýhodněné skupiny obyvatelstva. Povinností každého jedince, který chce žít v humánní společnosti, je snažit se svým způsobem a možností pomáhat znevýhodněným spoluobčanům v jejich životě, k možnosti navrácení do stylu života majoritní společnosti. Nutností je i šíření empatie k těmto skupinám lidí, kteří se ne vlastní vinou často dostanou do těžké životní situace. Každý z nás si musí být vědom toho, že hranice mezi úspěchem, životním naplněním či nezdarem je křehká., The article is devoted to problem of homeless people and beggars. This is focused on basic information about it as a social category of evidently poor people, living at the edge of majority society, which are characterized by specific way of their life. Each of us must be aware that the line between success and fulfilling life is fragile. It is the duty of every individual who wants to live in human society, seeking their own way, opting to help disadvantaged fellow citizens in their lives, the possibility of return to the lifestyle of the majority society. Only well-informed individual is able to understand the complex issues of mutual tolerance and equality for all people without biological and cultural differences (racism, religious intolerance, xenophobia and intolerance), including the necessary care for the disabled and socially disadvantaged groups., Jaroslava Pavelková, and Literatura
Tolerance of photosystem 2 (PS2) to high temperature in apple (Malus domestica Borkh. cv. Cortland) leaves and peel was investigated by chlorophyll a fluorescence (OJIP) transient after exposure to 25 (control), 40, 42, 44, and 46 °C in the dark for 30 min. The positive L-step was more pronounced in a peel than in leaves when exposed to 44 °C. Heat-induced K-step became less pronounced in leaves than in peel when exposed to 42 °C or higher temperature. Leaves had negative L-and K-steps relative to the peel. The decrease of oxygen-evolving complex (OEC) by heat stress was higher in the peel than in the leaves. OJIP transient from the 46 °C treated peel could not reach the maximum fluorescence (Fm). The striking thermoeffect was the big decrease in the relative variable fluorescence at 30 ms (VI), especially in the leaves. Compared with the peel, the leaves had less decreased maximum PS2 quantum efficiency (Fv/Fm), photochemical rate constant (KP), Fm and performance index (PI) on absorption basis (PIabs) and less increased minimum fluorescence (F0) and non-photochemical rate constant (KN), but more increased reduction of end acceptors at PS1 electron acceptor side per cross section (RE0/CS0) and per reaction center (RE0/RC0), quantum yield of electron transport from QA - to the end acceptors (ϕ R0) and total PI (PIabs,total) when exposed to 44 °C. In conclusion, PS2 is more thermally labile than PS1. The reduction of PS2 activity by heat stress primarily results from an inactivation of OEC. PS2 was more tolerant to high temperature in the leaves than in the peel. and L.-S. Cheng, L. Chen.