Quality and developmental changes in white head cabbage (Brassica oleracea L.) and radish (Raphanus sativus L.) during winter storage

Abstract

Thus many developmental processes, including cell division within the apical meristems and flowering, appear to depend on sugar-hormone signalling pathway. The aim of this study was to investigate the changes of quality indices and to evaluate the action of phytohormones and soluble sugars in developmental processes of Brassicaceae plants: white head cabbage (Brassica oleracea L., ‘Rocktor H’) and winter type radish (Raphanus sativus L., ‘Murzynka’) during winter storage. Radish and white head cabbage were harvested on the 19th of September and 14th of October, respectively. The switching from juvenile period (II organogenesis stage) to reproductive (III organogenesis stage) development started in November for white head cabbage and in January for radish, winter type, and conditioned the beginning of evocation processes. The mitotic activity of apical meristems started, and the development of floral meristems was observed only in spring – IV organogenesis stage was identified. Thus, this means that processes of II evocation stage can occur during storage, at low temperature conditions and in the dark for both plants. The increasing pattern of reducing sugars, sucrose, total sugars and soluble solids could be due to slower rate of hydrolysis of carbohydrates, which has implication for better quality maintenance. On the other hand, significant decline of hexoses (about 1.5 and 4.7 times in white head cabbage and radish, respectively) and sucrose (about 2.0 and 19.0 times in white head cabbage and radish, respectively), probably due to sugar cleavage, in storage organs of both harvested vegetables was observed during storage. The increasing pattern of hexoses, especially glucose (2.2 times in both plants), sucrose (7.5 times in white head cabbage), gibberellin (1.3 and 2.2 times in white head cabbage and radish, respectively) and indole-3-acetic acid (0.8 times in white head cabbage) during evocation (III and IV organogenesis stages) was observed in apical meristems of both plants.