Germinação in vitro, desenvolvimento inicial e micropropagação de cereus jamacaru em meios de cultura simplificados.

Abstract

Cereus jamacaru is a typical cactaceous from Caatinga, with importance for the sustainability and conservation of this biome, and exploited for ornamental and forage use. In vitro culture is a biotechnological tool that has been applied for germination, multiplication and conservation of different species of native cacti, however, it is a costly technique, which may have their costs reduced by modifying of some factors such as the culture medium. This study aimed to evaluate the in vitro germination and micropropagation of Cereus jamacaru using different culture media, cytokinins and light sources. The experiment was carried out in the Laboratório de cultivo in vitro de plantas of INSA, and took place in two stages: in vitro germination and early development of seedlings were used simplified culture media (½ CK and CK), composed of Calcinit and Kristalon fertilizers, and two different light sources (fluorescent and LED), while in micropropagation stage was used the CAC culture medium supplemented with 2 mg L-1 of the cytokinins BAP, KIN, TOP and TDZ. The results showed that the LED + ½ CK treatment exhibit the highest germination percentage (83%), and the LED lamps provided a better seedling development when compared to fluorescent; however, the light source do not interfere in the plant survival rate, which was 100% in both treatments after 30 days of acclimatization. For multiplication step, the medium containing BAP induced the formation of 4.3 shoots per explant inoculated, followed by TOP (3.1), KIN (2.5) and TDZ (0.9). However, the height of the shoots was inversely proportional to the number of shoots. Given the above, simplified culture media may be used for in vitro culture of mandacaru.