Nastanek površinskega kalusa pri navadnem divjem kostanju (Aesculus hippocastanum) : diplomsko delo - visokošolski strokovni študij

Pirnat, Marcel (author), Oven, Primož (mentor), Čufar, Katarina (reviewer)

Pri navadnem divjem kostanju (Aesculus hippocastanum L.) smo z lesnega cilindra odstranili skorjo v izmeri 30 x 30 mm. Na deblu smo naredili 8 poškodb 10. 8. 2006, vzorce pa odvzemali tedensko, vse do 28. 9. 2006. Z mikroskopom Nikon Eclipse E800 smo preiskovali histološki odziv na poškodbe v svetlem polju in v UV svetlobi. Zaporedja dogajanj smo analizirali kronološko. 7. dan po poškodbi na površini ranitve ni bilo moč opaziti nikakršne spremembe. V 14 dneh po poškodbi se je na površini razvila kalusna blazina. V njej je bilo mogoče anatomsko razlikovati 3 plasti: 1. tik ob eksponiranem lesu; 2. na površini kalusne blazine; 3. v osrednjem delu kalusne blazine. Na površini kalusa je bil že prisoten suberin v celičnih stenah. 21. dan po poškodbi so bile celice v notranjem delu kalusne blazine urejene v pravilnih radialnih nizih, na površini kalusne blazine pa so bile prisotne tudi debelejše celične stene. V osrednjem sloju kalusne blazine je bila zaznavna hiperplazija in hipertrofija celic. 28. dan po poškodbi je nastal nov plutni kambij, tik pod sklenjenim ligno-suberinskim slojem v tangencialni smeri. Na površini kalusne blazine so se pojavili tudi depoziti v lumnih celic, ki imajo, kakor tudi ligno-suberinski sloj, zaščitno funkcijo. 35. dan po poškodbi je bilo mogoče videti izrazitejši ligno-suberinski sloj. V osrednjem sloju kalusne blazine so se celice lignificirale v gnezdih. 42. dan po ranitvi se je pojavil vaskularni kambij, celične stene v kalusni blazini pa so se odebelile. Na 49. dan ni bilo delitvenih aktivnosti vaskularnega kambija. Pod ligno-suberinskim slojem so nastale nove, prav tako suberizirane plutne celice. Napredovala je tudi lignifikacija celic v tkivu pod in nad kambijem. Spremembe v ranitvenih tkivih so se odvijale vse do 28. 9. 2006. Aktivnost meristemov v normalnih rastnih pogojih se v tem času, na tej geografski širini, že konča. Ključna posledica poranitvenih aktivnosti je bil nastanek ligno-suberinskega sloja, ki zaščiti poškodovano območje pred izsuševanjem in okužbo z glivami.

• Language: Slovenian
• Keywords: navadni divji kostanj, Aesculus hippocastanum, les, skorja, poškodba, kalus, lignosuberinski sloj
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [M. Pirnat]
• Year: 2009
• Number of pages: XI, 36 f.
• PID: 20.500.12556/RUL-383-6f7c5c16-69c0-8517-a2be-0df54b03d956
• UDC: 630*416:630*176.1
• COBISS.SI-ID: 1744265
• Publication date in RUL: 11.07.2014

Secondary language

• Language: English
• Title: Formation of surface callus in horse chestnut (Aesculus hippocastanum) : graduation thesis - higher professional studies

Abstract

A 30 x 30 mm segment of bark was removed from the wooden cylinder of a horse chestnut (Aesculus hippocastanum L). On August 10, 2006, 8 wounds were inflicted upon the trunk and samples were taken weekly until September 28, 2006. Histological changes were examined in the bright field and UV light, using a Nikon Eclipse E800 microscope. The progression of occurrences was analyzed chronologically. On the 7th day after the wound infliction, there was no change on the wound surface. 14 days after the infliction, the callus tissue started to develop on the wound surface. This tissue consisted of 3 anatomical layers; 1st directly on the exposed wood, 2nd on the surface of the callus tissue, and 3rd in the middle part of callus tissue. The presence of suberin could already be observed. On the 21st day after the infliction, the cells in the middle part of the callus tissue were arranged in proper radial rows; thick cell walls started to form on the surface. In the middle layer, there was evidence of cell hyperplasia and hypertrophy. On the 28th day after the infliction, formation of new cork cambium could be observed right under the ligno-suberin layer in the tangential direction. On the surface of the callus tissue, some deposits of lumen cells were found, which together with the ligno-suberin layer, act as protection. On the 35th day after the infliction, the ligno-suberin layer was clearly visible. In the middle layer of the callus tissue, the cells started to lignificate in nests. On the 42nd day after the infliction, formation of vascular cambium and thickening of cell walls in the callus tissue was observed. On the 49th day, the process of division in the vascular cambium was no longer observed. Under the ligno-suberin layer, new cork cells were formed that were also suberized. The lignification of tissue cells over and under the cambium progressed as well. Changes in wounded tissues had been occurring until September 28, 2006. At that time period the phytological activity of meristems under normal growth conditions at this latitude already ends. The key event in the post-wound reaction was the formation of ligno-suberin layer that protects the wounded area from drying out and from fungus infection.

• Keywords: horse chestnut, wood, bark, damage, callus, ligno-suberin layer