The symbiotic association of endophyte fungus, Neotyphodium lolii, and ryegrass improves the ryegrass resistance to drought. This is shown by a 30 % increase in the number of suckers in infected plants (E+), compared to plants lacking endophyte (E-), and by a higher water potential in the E+ than E- plants. The E+ plants have higher stomatal conductance (gs), transpiration rate, net photosynthetic rate (PN), and photorespiratory electron transport rate than the E- plants. The maximal photochemical efficiency (Fv/Fm) and the actual photochemical efficiency (ΦPS2) are not affected by the endophyte fungus. The increase in PN of the E+ plants subjected to water stress was independent from internal CO2 concentration. An increased PN was observed in E+ plants also in optimal water supply. Hence the drought resistance of E+ plants results in increased gs, PN, and photorespiratory electron transport rate. and C. Amalric ... [et al.].
This article discusses the influence of the great inequality of Jupiter and Saturn on the stability of the solar system. The main theoretical study of planetary perturbations usint the method of variation of orbital parameters, was evolved by Euler and Lagrange in the eighteenth century. Subsequently Laplace introduced a method for solving a collection of simultaneous differential equations suited for planetary perturbation theory. He clarified that there are limited variations of orbital elements - excentrities, inclinations and semi-major axes. This was the proof required for the stability of the solar system., Vladimír Štefl., and Obsahuje seznam literatury