The Impact of Seasonal Changes in Plant Tissue on Rhizogenesis of Stem Cuttings of Once Blooming Roses

Abstract

The majority of old and long-to-root roses are enough frost resistant to grow on their own roots in moderate and coolclimates. The most often used method of rose propagation are single node stem cuttings derived from blooming shoots. Thelong duration of rhizogenesis exposes cuttings to stress conditions and precocious ageing processes, which result in a lowrooting percentage. It was hypothesized that in the short season of flowering the amount of nutrients in shoots of stock plantschanges, thus affecting the process of rhizogenesis, as well as a condition of rooted cuttings, which may be estimated by thecontents of the biologically active components. The shoots of four rose cultivars were cut in four phenological stages: flowerbuds closed, flowers opened, just after petal shedding and 7-14 days after petal fall. The rooting percentage were counted after10 weeks of rooting. The evaluation of plant material were carried out before and after rooting, including: soluble proteins,chlorophyll a and b, carotenoids, polyphenolic acids, reducing and total soluble carbohydrates. The research revealedvariability, characteristic for each examined cultivar, in the contents of the biologically active compounds, both before and afterrooting, in cuttings harvested from stock plants in successive phases of development. Decrease in pigment contents in leaves ofrooted cuttings may suggest a progressing senescence, both during propagation and later in a vegetative season. The cuttings of‘Mousseuse Rouge’ rooted similarly when harvested in each of the phenological phases (53.8-67.5%). For other cultivars thehighest rooting percentage was obtained for cuttings harvested from shoots with closed flower buds: (‘Hurdals’ 47.5%,‘Maiden’s Blush’ 55.0%, ‘Semiplena’ 67.5%). In these cultivars a relationship between rooting percentage and changes in thecontents of pigments, sugars or/and polyphenolic acids in successive phenological phases was shown.

The Effect of Biostimulators and Indole-3-Butyric Acid on Rooting of Stem Cuttings of Two Ground Cover Roses

“…In the current experiment, the effects of biostimulators on the rooting of roses were comparable to or only slightly weaker than those of synthetic auxin IBA. These results are in agreement with those of recent trials to optimize propagation of old historical roses with such biostimulators as Bio Rhizotonic, Bio Roots, and Root Juice used to water the cuttings during the rooting period (Monder et al, 2014(Monder et al, , 2016. Positive effects of these preparations on rooting of Rosa gallica 'Duchesse d' Angoulême' (Monder et al, 2014), Rosa beggeriana 'Polstjärnan' and Rosa helenae 'Semiplena' were reported (Monder & Pacholczak, 2018).…”

“…The increase in chlorophyll levels in cuttings of two dogwood (Cornus alba L.) cultivars ' Aurea' and 'Elegantissima, ' caused by biostimulator application, was also reported (Pacholczak et al, 2012). Conversely, a decrease in chlorophyll a and b were observed in cuttings of the historical roses R. ×alba 'Maiden Blush' and R. helenae 'Semiplena' treated with biostimulators (Monder et al, 2016), however rhizogenesis was not negatively affected. The change in chlorophyll concentration may be a plant response to stress, which suggests an increase in plant stress tolerance resulting from biostimulator applications (Kranner et al, 2003).…”

“…Different plants watered with solutions of Aminoplant and Goëmar Goteo also exhibited lowered levels of phenolic compounds (Rosłon et al, 2011). A different response to the treatment with rooting enhancers was observed in historical roses, where the treated cuttings contained higher or comparable amounts of polyphenolic acids as the untreated cuttings (Monder et al, 2016;Monder & Pacholczak, 2019).…”

“…The application of IBA (Rhizopon AA or water solution) and biostimulators (Goteo and AlgaminoPlant) resulted in the increased sugar concentration in the cuttings of both cultivars. Positive effects of biostimulators and auxins on sugar levels in cuttings of historical roses have been previously reported (Monder et al, 2016;Monder & Pacholczak, 2018). Such a response in cuttings to the application of rooting enhancers is crucial for successful rhizogenesis because the effectiveness of photosynthesis in cuttings during rooting is low.…”

“…The easiest and most economical technique is to root twothree nodal leafy cuttings taken from flowering shoots (Wiśniewska-Grzeszkiewicz & Podwyszyńska, 2001). Rooting of roses is a long process during which cuttings are subjected to numerous environmental stresses (Ginova et al, 2012;Monder et al, 2014Monder et al, , 2016. To improve rose rooting success, growth regulators, especially auxins, such as IBA (indole-3-butyric acid) are commonly used (Cárderas-Navarro & López-Pérez, 2011;Hoşafçi et al, 2005;Kroin, 2014;Nasri et al, 2015).…”