Cultivo in vitro de meristemas de batata-doce

Abstract

The search for a virus-free vegetative material, with high physiological and phytosanitary quality, has been growing year after year. A solution to this is the use of tissue culture techniques, or in vitro cultivation of plant tissues carried out in the field of plant biotechnology area. This technique has great value, as it makes possible the production of mother plants in an aseptic manner in controlled environments, without any type of stress that could harm the plant's development. Therefore, the use of in vitro cultivation can help to improve the sweetpotato reproduction and propagation cycle. The aim of this study is to regenerate different Ipomoea potato genotypes from apical meristematic explants in two culture media supplemented with plant growth regulators. The mother plant tubers were planted in pots with soil and substrate. After the formation of sprout from the parent plants, the explants were removed from them, and these were collected from shoot tips from the shoot of the plants. The explant used was the meristem with sizes from 1 to 2 mm, which was introduced in vitro in two different culture media, one being the MS medium (Murashige and Skoog, 1962) without growth regulator and the other the MS medium with 10 mg L-1 of GA3, both supplemented with 30 g L-1 of sucrose and 8 g L-1 of agar as gelling agent, with a pH of 5.7. The experiment consisted of three sweet potato genotypes (BRS Amélia, Beauregard and BRS Rubissol). After introduction, the number and height of shoots, the percentage of contamination and explant regeneration, and the development of genotypes in both culture media were evaluated weekly. The data were subjected to analysis of variance (ANOVA) and when a significant difference was observed between the analyzed variables, with a 5% level of significance, a mean cluster analysis was performed using the Tukey test, in order to identify the most efficient culture medium for each genotype evaluated. The culture medium that showed more contamination was the MS medium. Statistical differences were found for number of shoots and shoot length in cultivars BRS Amélia and BRS Rubissol, while cultivar Beaurigard did not show a statistically significant response to medium change. Thus, for cultivar BRS Amélia, the MS medium supplemented with GA3 increased the number of shoots in a shorter period of time, but had no significant effect for the variable shoot height. For the BRS Rubissol cultivar, the MS medium with GA3 showed the highest number and height and shoots after 21 days of the experiment.