Protocolo para desinfecção de orquídeas do gênero Cattleya

Abstract

In the gift of “blossoming” the human emotional, orchids cultivation occurs about 4000 years ago. Cattleya genus has 108 species being the largest orchids genus. However, due to their beauty, they are taken excessively from nature, leading countless species to extinction. Additionally, they are difficult to propagate under natural conditions due to the low germination rate of their seeds, which do not have an endosperm. Micropropagation is an alternative for orchid production, producing elite plants in a small physical space and in a short period of time, regardless of limiting climatic factors and also avoiding plant pathogens. In this sense, this work aimed to establish disinfection conditions for in vitro cultivation of Cattleya orchids. In this work, the medium used in the orchids cultivation was MS/2, supplemented with hormones and additional compounds. Disinfection was performed on three different tissues: the entire bud, isolated meristems and meristems with surrounding tissues. From each shoot, it was possible to obtain 3 meristems. Disinfection from whole shoots immersed in 0.75% hypochlorite for 12, 15, and 20 minutes was not achieved, which required disinfection from tissues into smaller fragments. The isolated meristem and the meristem with surrounding tissues were used. These tissues were disinfected at different times and concentrations of sodium hypochlorite and Kathon. Anyway, the best result was using the meristem with surrounding tissues, which protect the meristem reducing oxidation. This tissue was most efficiently disinfected using 0.5% sodium hypochlorite for 30 minutes. Work has been done to get more tissues disinfected and additional experiments will be needed to achieve micropropagation of Cattleya orchids.