HISTOLOGICAL ANALYSIS OF ORGANOGENESIS AND SOMATIC EMBRYOGENESIS DURING SHOOT FORMATION IN SUGAR BEET (BETA VULGARIS L.) VIA GYNOGENESIS

摘要

The aim of the present research were histological analysis of regenerating structures through in vitro gynogenesis from unfertilized ovules of sugar beet (Beta vulgaris L.). The process of shoot regeneration using a novel two stage method combines thepreculture in liquid medium with the culture on solid medium. The highest number of explants that formed shoots (60%) was observed on medium supplemented with BAP, sucrose and gerlite, and as regards carbohydrates used in the medium most of explants forming shoots (42%) and the largest total number of shoots (110) was observed for glucose. To accurately determine the course of shoot formation, histological analyses were performed. Careful histologic evaluation of regenerating structures revealed the presence of numerous meristematic centres. In some meristems formation of specialized tissues and organs was observed, including epidermis, apical meristem, leaf primordia and tracheal elements. The analyses showed that the regeneration of the new structures from sugar beet ovules occurred both through organogenesis as well as somatic embryogenesis since the presence of somatic embryos in the globular stage or torpedo stage were observed.