Rhizogenesis in Shrub rose cultivated in vitro

Abstract

The study of the reproduction characteristics of roses of the garden class Shrub, the definition of the dependence of the hormonal determination of explant rhizogenesis on the concentrations of phytohormones that are part of the nutrient media, is relevant and has both scientific and practical interest. The article presents the results of studies of hormonal determination of rhizogenesis in explants of cultivars of roses of the garden class Shrub: ‘Gärtnerfreude’ (W. Kordes’ Söhne, 1991), ‘Lavender Dream’ (G. P. Ilsink, 1984), ‘Pomponella’ (W. Kordes’ Söhne, 2005), ‘Red Cascade’ (R. S. Moore, 1976), ‘Sommerabend’ (W. Kordes’ Söhne, 1995) cultivated in vitro on nutrient media containing growth regulators. It has been established that of the nutrient media modified by the addition of 0.2–1.0 mg/l α-naphthylacetic acid (α-NAA), the most effective was the medium with the content of α-NAA 0.5 mg/l, the content of macro- and microelements half of the Murashige and Skoog prescriptions, and a decrease in the sucrose content to 2.0%. On this medium, the frequency of rhizogenesis averaged 61.2% for the studied cultivars. Hormonal determination of rhizogenesis and efficiency of root formation in vitro in the Shrub rose regenerants depended on the genotype of the plant (the cultivar): cv. ‘Gärtnerfreude’ (61.0%) and cv. ‘Lavender Dream’ (66.0%) had the highest rhizogenesis ability. The use of the universal growth regulator “Humifield” in combination with 0.5 mg/l α-NAA contributed to an increase in the rooting rate of the studied rose cultivars up to 70.0–86.0%.