Crescimento in vitro de Alcantarea imperialis submetida a elicitores em diferentes condições de cultivo

Abstract

Alcantarea imperialis (Carrière) Harms is an Atlantic Forest endemic bromeliad widely used in landscaping due to its high ornamental value and exuberant size. However, its propagation is limited by the low production of seedlings and slow growth, making micropropagation an important strategy for plant production and species conservation. In this context, the present study aimed to evaluate the effects of salicylic acid (AS) and jasmonic acid (AJ) on the in vitro growth of A. imperialis plantlets cultivated under two temperatures (25 and 30 °C). The experiment was conducted in a completely randomized design using a 2 × 9 factorial arrangement, consisting of two temperatures and nine treatments (control, four concentrations of AS, and four concentrations of AJ). The number of shoots, number of leaves, shoot length, root system length, number of roots, fresh mass, dry mass, survival rate, and electrolyte leakage of the plantlets were evaluated at 30 and 60 days of cultivation. The data were subjected to ANOVA and regression analysis. The results depended on elicitor concentration and cultivation temperature. Salicylic acid showed less favorable effects at higher concentrations, especially at 30 °C, reducing growth and survival while increasing evidence of cellular damage in the plantlets. In contrast, jasmonic acid promoted leaf and shoot formation while maintaining high survival throughout the cultivation period. It was concluded that jasmonic acid showed greater potential for application in the micropropagation of A. imperialis, whereas high concentrations of salicylic acid reduced survival and inhibited leaf and root formation as well as shoot growth, and should therefore be avoided, especially under higher temperature conditions.