|
|
Leaf physiological and optical properties in relation to the Phytophtora × alni infection of black alder (Alnus glutinosa)
Oramová, Viktorie ; Lhotáková, Zuzana (advisor) ; Tomášková, Ivana (referee)
A current problem is the infestation of the black alder (Alnus glutinosa) by the pathogen P. × alni, which causes the loss of alder stands and disrupts riparian ecosystems. The spread of the 'phytophthora disease' occurs through water, the host is infected through the root system and the pathogen attacks the conductive tissues. As a result of the disease, the tree gradually loses its root system, lesions appear on the trunk, defoliation occurs and the individual inevitably dies. The only solution to the situation is preventive measures to prevent further spread by careful removal of infected alder trees. The aim of this paper is to discuss the relationship between black alder and P. × alni in the context of the physiological changes that occur in the foliage of the infested individual. Leaf functional traits, chlorophyll fluorescence and optical properties of black alder exposed to P. × alni (inoculation into soil or confirmed occurrence of the pathogen in natural conditions) were measured using non-invasive methods. The results of the chamber experiments suggest that the mean values of the measured parameters do not change significantly in the initial stages of infection, but there is a widening of the variance of the values in infected individuals. We tested whether the genetic origin of the...
|
|
|
The phenomenon of Foliar Water Uptake - mechanisms and consequences with a focus on temerate plant species
Oramová, Viktorie ; Lhotáková, Zuzana (advisor) ; Ponert, Jan (referee)
The ability of plants to absorb water through leaves has been a matter of the sientific discussion for a long time. Among the epiphytic species (tilandsies for example), reduced root system and foliar water uptake (FWU) is considered an adaptation for life in soil-less environment, and FWU is a necesssity. It was surprising, that the same ability has been discovered in plant species with normally developed root system. Over the time, new pieces of evidence about FWU in broad range of plant species has been published and FWU is getting universal for all plants, across the taxonomic groups or biomes, including temperate zone. The systematic focus on FWU and continuity of its research is lacking and therefore the knowledge about FWU is still only partial. This bachelor's thesis is focused on mechanisms of FWU and the leaf structures that may mediate it. The ability of water to pervade cuticle through aquatic pores is discussed, together with the possibility of water absorption by stomata, trichomes, hydathodes or epiphylic organisms. Another discussed topic is the use of this water by plant - improving of the water regime, refilling of the embolized xylem vessels, possible exudation by roots etc. The matter of FWU has other consequences on the ecosystem level, like in water cycle or the plant's...
|
guest ::
