Anatomical structure changes in stem cuttings of rambler roses induced with plant origin preparations

Abstract

The plant hormones such as indolebutyric acid (IBA) or naphthalene acetic acid (NAA) and biostimulants are used to enhancing the root formation in cuttings and affect many aspects of plant growth. The aims of this experiment were to evaluate response of the single-node rose stem cuttings to the plant origin preparations enhancing rhizogenesis so the changes in anatomical structure of stem basal part were studied. The one-bud stem cuttings of once-blooming ramblers Rosa beggeriana ‘Polstjårnan’ and R. helenae ‘Semiplena’ were made in four phenological stages: flower buds closed, open flowers, just after petal fall and 7–14 days after petal shedding; and were treated with: the standard commercial powder preparations containing 0.4% indolebutyric acid (IBA) or 0.2% naphthalene acetic acid (NAA) and with the commercial plant origin preparations work named: Algae extract, Organic preparation and Plant extract. The anatomical structure of the stem base was studied in rooting period (25 days), while the rooting percentage and parameters of growth (root length, weight of root and aboveground part) were estimated after 12 weeks. The anatomical structure of stems before and after rooting was typical for Rosa species, but differed in cuttings harvested in four phenological stages in the region of rhizogenesis in stems. The visible outside the cutting callus appeared after 7 or 10–14 days in ‘Polstjårnan’ and ‘Semiplena’, respectively, while the first roots became visible there after 3–4 weeks. The adventitious roots were usually formed in tissues of the cambial zone near pith rays and also in the phloem and pericycle. In ‘Semiplena’ the use of the NAA preparation resulted in the abundant production of callus which obstructed root initiation and decreased the rooting percentage. In both of varieties, all the preparations affected diameters of wood cells and width of xylem, cambium and phloem tissues depends on phenological phase. The width of cambium and phloem becomes wider while the wood cells diameter decreases but accordingly to used preparations. However, the changes in anatomical structure correlated in low significance with rooting percentage.