PLANT PHYSIOLOGY AT THE INSTITUTE FOR PHILOSOPHY IN BRNO IN MENDEL'S TEACHER F. DIEBL TEXTBOOK FROM 1835

Abstract ŠEBÁNEK, J.: Plant physiology at the institute for philosophy in Brno in Gregor Mendel attended lectures of F. Diebl, professor of natural history and agricultural science at the Institute of Philosophy in Brno. Diebl published his lectures in a textbook "Abhandlungen über die allgemeine und besondere Naturgeschichte, Brünn 1835." From the textbook the level of scientifi c knowledge in plant biology is obvious, with which the later founder of a new fi eld of biology -genetics got acquainted. Diebl considered germination to be a specifi c method of fermentation transforming seed starch into a sugary matter which nourishes the germinating plant. In the physiology of nutrition he distinguished nutrition from the soil via roots from nutrition from the air via leaves. The former is based primarily on the humus theory of A. Thaer (1809) because not until 5 years a er the publication of Diebl's textbook J. Liebig initiated the mineral theory. Diebl's presentation of photosynthesis was based on information available at that time about the release of oxygen by green plants under conditions of light and the uptake of CO 2 , but he had no knowledge about the passage of CO 2 into the leaves through stomata. Remarkable is Diebl's discovery that respiration increases during fl owering. Electricity is considered to be a force signifi cantly supporting the life processes of plants. Diebl also noticed the diff erence between diurnal and night evaporation of water from the leaves. In his textbook growth is connected with nutrition only, as it was the entire 19 th century. Stem thickening from the cambium is described very simply. Bud and root regeneration is given the term reproduction which today is commonly used in relation to sexual reproduction. Diebl considered nyctinastic movements (bending or unbending of the leaves) and closing of the fl owers at night to be "sleep". He described fertilisation in a primitive way, because it was not until 1848 that the fi rst exact description came out. plant physiology in textbook from 1835, germination, nutrition, growth and reproduction, period of rest, plant propagatio