Study of histostructure of ray parenchyma and rooting ability of Sievers apple (Malus sieversii) endemic species in green cutting

Abstract

Wild apple forests represent a unique gene pool of not only our country but the entire planet. Therefore, conservation of genetic resources and restoration of wild fruit forests is an important task, and to solve it without help of research and financial support is impossible. In the absence of urgent and effective steps to study the biological features of wild Sievers apple structure and obtaining productive technologies of reproduction, the area of apple trees in the Dzhungar Alatau mountain range may be cut down by more than a third in 2030. One of the effective ways of vegetative propagation of fruit crops is green cutting. The established correlation between the structure of medullary rays and the degree of rooting with green cuttings from different rooting ability of fruit plant sorts allows identifying the potential plant rooting with green cuttings. Therefore, the study of radial parenchyma of Sievers apple trees and rooting degree of green cuttings of this endemic species is an urgent problem, requiring a timely solution. The research aim is to study the structure of medullary rays of annual shoots of the wild Sievers apple tree stem and to determine the potential degree of rooting with green cuttings. Raw materials, storage, annual shoots, preparation of anatomical slices, staining and examination of slides of medullary rays’ histostructure are conducted with proven conventional methods in anatomy by means of modern microscopic equipment. Counting, measuring and description of medullary rays are made with A. A. Yatsenko-Khmelevsky’s method. Statistical data processing was carried out with conventional biometry methods. As a result of the conducted research, the medullary rays of annual shoot stems on transverse and longitudinal sections were examined on tangential and radial cuts. We also calculated the number of rays, measurements of rays and ray cells. The description of radial parenchyma, which is typical for the stem of Sievers apple annual shoots, is conducted. Anatomical photos of rays on the transverse and longitudinal sections are taken. The analysis of obtained results is carried out and the potential level of rooting of Sievers apple green cuttings by the histostructure of radial parenchyma is identified.