ABSTRACT
The goal of the present study was to evaluate the acaricidal potential of Lippia alba essential oil, citral chemotypes (LA-10 and LA-44 genotypes) and carvone chemotypes (LA-13 and LA-57 genotypes), as well as purified citral and enantiomers of carvone and limonene. Efficacy against Rhipicephalus microplus was assessed by the larval packet and the engorged female immersion tests. Citral chemotypes had greater larvicidal activity than carvone chemotypes, and this was further supported by larvicidal and adulticidal activity of purified citral with LC50 values of 7.0 and 29.8 mg/mL, respectively. While purified enantiomers of carvone exhibited greater larvicidal activity than those of limonene, enantioselectivity of limonene was observed with R-(+) displaying significantly higher efficacy (LC50 of 31.2mg/mL) than S-(-) (LC50 of 54.5mg/mL). The essential oils and purified compounds were much less toxic toward engorged adult females, with the exception of citral, and this may be due to limited cuticular penetration.
Subject(s)
Acaricides/pharmacology , Genotype , Lippia/chemistry , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Rhipicephalus/drug effects , Acaricides/chemistry , Acyclic Monoterpenes , Animals , Cyclohexane Monoterpenes , Cyclohexenes/chemistry , Cyclohexenes/pharmacology , Female , Limonene , Lippia/genetics , Monoterpenes/chemistry , Monoterpenes/pharmacology , Oils, Volatile/chemistry , Plant Oils/chemistry , Terpenes/chemistry , Terpenes/pharmacologyABSTRACT
The aim of this study was to develop a protocol for the in vitro conservation of sweet potato genotypes using the slow growth technique. The first experiment was conducted in a 4 × 5 × 2 factorial scheme, testing four genotypes (IPB-007, IPB-052, IPB-072, and IPB-137), five concentrations of abscisic acid (ABA) (0.0, 1.0, 2.0, 4.0, and 8.0 mg·L⻹), and two temperatures (18 and 25°C). The second experiment was conducted in a 4 × 3 × 3 factorial scheme at 18°C, testing four genotypes (IPB-007, IPB-052, IPB-072, and IPB-137), three variations of MS salts (50, 75, and 100%), and three concentrations of sucrose (10, 20, and 30 g·L⻹). Every three months, we evaluated the survival (%), shoot height, and shoot viability. In vitro conservation of the sweet potato genotypes IPB-052 and IPB-007 was obtained over three and six months, respectively, using MS medium plus 2.0 mg·L⻹ of ABA at either 18 or 25°C. Genotypes IPB-072 and IPB-137 can be kept for three and six months, respectively, in MS medium without ABA at 18°C. It is possible to store IPB-052 and IPB-072 for six months and IPB-007 and IPB-137 for nine months using 30 g·L⻹ of sucrose and 50% MS salts.
