Mesocomponentes, qualidade de luz e elicitores na micropropagação e análise química volátil de Chenopodium ambrosioides L. (Chenopodiaceae)

Abstract

Chenopodium ambrosioides L. is a medicinal plant, popularly known as Erva-de-santa-maria, mastruz or epazote, used as anthelmintic. In the Brazil there is interest in your study because it is listed in the RENISUS. The possibility of multiplying clones in large quantities and in small space are advantages of tissue culture. The objective of this study was to study the concentrations of meso components, the light quality and the use of elicitors on the growth and production of volatile constituents of C. ambrosioides in vitro. The present work was divided in three experiment. The first was different concentrations of magnesium sulfate heptahydrate (0; 185; 370; 740; 1480 mg L-1), calcium chloride dehydrate (0; 220; 440; 880; 1760 mg L-1) and monopotassium phosphate (0; 85; 170; 340; 680 mg L-1) in the MS medium were evaluated. The most adequate meso components intervals in MS medium for the maintenance of C. ambrosioides nodal segments in vitro are: 1039 to 1069 mg L-1 of MgSO4.7H2O; 958 to 1301 mg L-1 of CaCl2.2H2O and 329 to 397 mg L-1 of KH2PO4. The major constituent Z-ascaridole had the biggest content in 352 mg L-1 of KH2PO4 and the smallest content in 770 mg L-1 of MgSO4.7H2O and in 1097 mg L-1 of CaCl2.2H2O. In the second, nodal segments were inoculated in culture medium and kept for 40 days in a growth room with different diodes emitting light (LEDs): blue; red; white; and combinations between blue and red (1:1; 2:1; 1:2) and cool white fluorescent lamp. The best growth of nodal segments was observed in the treatments with illumination coming from white LED lamps or in combination blue/red (2:1). Monochromatic LEDs in the color blue result in increments of α-terpinene and p-cymene in detriment of Z-ascaridole. In the third, five concentrations of chitosan (0, 50, 100, 150, 200 mg L-1) and five concentrations of salicylic acid (0, 3, 6, 9, 12 mg L-1) were added to the MS medium. The chitosan and salicylic acid had a negative effect on the growth and development of C. ambrosioides nodal segments. The major constituent Zascaridole presented higher content in 61.11 mg L-1 of chitosan and in 7.79 mg L-1 of salicylic acid.