Utilização de caracteres agronômicos, fisiológicos e fitoquímicos na seleção e melhoramento de Artemisia annua L.

Abstract

Artemisia annua is a plant which produces artemisinin and various other compounds by its specialized metabolism, used commercially to malaria control. Several researches have been developed to acclimatise and improve this species in CPQBA/Campinas and UTFPR/Pato Branco. The present study aimed to correlate the physiological, agronomic and phytochemical characteristics with the content and yield of artemisinin (ART e REND) in the selection and improvement of A. annua. For the selection of the best plants it was used the Stratified Mass Selection with 30 strata and 33 plants per stratum. The first plants selection was performed using agronomic criteria with subsequent roguing of the unselected plants and borders. Biotic and environmental factors impacted the viability of plants evaluation, leaving 138 plants with viable seeds, in which the physiological, agronomic and phytochemical evaluations were performed (thin layer chromatography – TLC) and selected 50 plants for analysis of artemisinin and dihydroartemisinic acid content in HPLC and essential oil phytochemical profile by GC-MS. The statistical analyzes of mean were performed using the R platform, correlation analyzes with the Genes software® and selection indexes with the GGE Biplot app. Tests and analyzes of artemisinin with TLC showed a weak positive correlation with HPLC analyzes. The IMAGEJ program showed high efficiency in the quantification of artemisinin by TLC. The physiological characters showed no correlation with ART and REND. Among the agronomic characters, leaf dry weight (PSF) and Biomass presented weak negative correlation with ART, and the characters PSF, Biomass, stem diameter and ART showed a positive correlation with REND. Among the phytochemical characters, dihydroartemisinic acid presented weak positive correlation with ART, Cis-cadin-4-en-7-ol correlation with ART and REND, oil yield (OLS) correlation with REND, and ART correlation with REND. The average analysis of the genotypes by morphological characters showed a 62% higher average for the character 1.8-cineole in the plants of purple branch, compared to the green ones. The average of artemisinin content and yield of the analyzed genotypes was 0.73% and 26,15 kg.ha-1 (D.B.), respectively. The artemisinin content and yield of the 20 best genotypes, classified in artemisinin content by HPLC, were 29% and 27% higher, respectively, compared to the 50 genotypes analyzed. The average oil content per plant was 0.72%, with an average yield of 26.37 kg.ha-1 (D.B.). The major components of CPQBA 3 essential oil were camphor, germacrene D, trans-caryophyllene, trans-β-farnesene and 1.8-cineole.