Razvoj nadomestnega koreninskega sistema pri hibridnih pelargonijah (Pelargonium spp.)

Kupšek, Katarina (author), Osterc, Gregor (mentor)

Pri pridelavi sezonskih rastlin je nujno hitro in kakovostno razmnoževanje rastlin. To omogočajo »Ready-rooter« potaknjenci, ki imajo na bazi potaknjenca že razvit kalus. Kasnejše koreninjenje je hitrejše in uspešnejše. Obdobje gojenja je tako krajše kot pri nekalusiranih potaknjencih. V okviru magistrske naloge smo tako proučevali razvoj nadomestnega koreninskega sistema (NKS) pri pelargonijah različnih hibridov (pokončnih in povešavih). Spremljali smo razvoj kalusa in kasneje tudi kakovost in arhitekturo NKS v odvisnosti od aplikacije eksogenih avksinov na potaknjence pred potikom. Uporabljali smo različne avksinske pripravke, ki se v praksi pogosto uporabljajo. Zanimala nas je dinamika tvorbe ključnih avksinov za razvoj NKS, indol-3-ocetne kisline (IAA) ter njenega metabolita indol acetil aspartata (IAA-Asp). Naredili smo ekstrakcijo avksinov in dobili povprečne vsebnosti avksinov v različnih časovnih obdobijih po potiku. Raziskava je pokazala, da povprečna vsebnost IAA naraste ob potiku in ostane visoka do 4 ur po potiku. Po 4 urah je največkrat močno padla. Dvig IAA mora biti zmeren, saj prevelike vsebnosti vodijo v slabši razvoj NKS. Padec vsebnosti IAA v kasnejših fazah razvoja je nujen, saj prevelike koncentracije IAA zavirajo razvoj korenin. Morfološka opazovanja so potrdila, da ima sorta pomemben vpliv na razvoj NKS in vsebnost IAA. Razvoj kalusa in NKS je potekal hitreje pri sortah 'Tango Dark Red' in 'Caliope Dark Red' kot pri sorti 'Feuer Cascade'. Statistična analiza rezultatov je pokazala, da je bila pri sorti 'Feuer Cascade' ves čas veliko večja povprečna vsebnost avksinov v potaknjencih v primerjavi s povprečno vsebnostjo avksinov pri sorti 'Tango Dark Red', kar verjetno lahko razloži slabše koreninjenje potaknjencev sorte 'Feuer Cascade'.

• Language: Slovenian
• Keywords: razmnoževanje s potaknjenci, okrasne rastline, pelargonije, avksini
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [K. Kupšek]
• Year: 2021
• PID: 20.500.12556/RUL-126495
• UDC: 635.921:582.752.3:631.535:631.533.1(043.2)
• COBISS.SI-ID: 60907011
• Publication date in RUL: 24.04.2021

Secondary language

• Language: English
• Title: Development of adventive root system in hybrids of Pelargonium (Pelargonium spp.)

Abstract

The master's thesis comprises of a detailed study on the development of geranium adventitious root system of different hybrids (upright and hanging). An observation of the key auxins formation dynamics during the development of adventitious root system, indole-3-acetic acid (IAA) and its metabolite indole acetyl aspartate (IAA-Asp) was made. The development of callus and the quality, as well as the architecture of the adventitious root system, was studied with regard to the exogenous application of cuttings before inserting in substrate with several auxin substances usually used in practice. When producing seasonal plants, 'Ready-rooter' cuttings which have a callus already developed at the base of the cutting are considered as a high-quality planting material. Subsequent rooting in these cuttings is faster and more successful and, as a result, the growing period is shorter than for non-callusing cuttings. Based on auxin analyses, the average auxin contents in different time periods after severance was obtained. The study has shown that the average IAA content increased during the insertion of cuttings in substrate and remained high for up to 4 hours after the insertion. After 4 hours, the content was considerably reduced. The increase of IAA should be moderate, considering that too high contents can lead to the underdeveloped adventitious root system. A decrease in IAA content in later stages of development is necessary, due the high IAA levels can slow the root development. Morphological observations have confirmed that the cultivar has a significant influence on the development of adventitious root system and on the IAA level course. The development of callus and adventitious root system was faster in 'Tango Dark Red' and 'Caliope Dark Red' cultivars than in 'Feuer Cascade' cultivar. The statistical analysis of the results showed that the 'Feuer Cascade' variety had a much higher average endogenous auxin content in the cuttings in comparison to the average auxin content of the 'Tango Dark Red' cultivar. This can probably explain the more difficult rooting capacity of the 'Feuer Cascade' cultivar.

• Keywords: propagation with cuttings, ornamental plants, geraniums, auxins