Genotype and Environmental Effects on Physical and Chemical Qualities of Mexican Varieties of Hibiscus sabdariffa L. Flowers
This study evaluated 53 red color-contrasting genotypes of Hibiscus sabdariffa L. of dehydrated calyces grown in a traditionally producing regions of Colima, Guerrero, Nayarit, Oaxaca and Puebla states in Mexico. The objective was to quantify the effects of genotype (G), environment (A, location) and interaction (GXA) on color variables (luminosity, hue and saturation), total anthocyanin content (CTA), total soluble phenols (FST), pH and titratable acidity (AT) in dehydrated calyces and aqueous extracts. The three factors had significant effects (p≤0.01) on calyx quality and extracts. But the genotype factor influenced more calyx color (60 to 81 %), CTA (72 %) and FST (44 %), while calyx color tone was mostly explained (62 %) by the interaction GXA. pH and AT were affected more by location (56 and 52 %) and by the GXA interaction (22 y 24 %). Nineteen genotypes were classified as dark red calyces, which contained higher total soluble anthocyanins and phenols levels; these variables showed higher expression at the Nayarit location. The remaining light-red calyx genotypes (34) were highly acidic, and the acidity increased when grown in Nayarit. Although the three effects of genotype, location (environment) as well as their interaction GA had significant effects on the quality of hibiscus calyces, the genotype factor was the most relevant to CTA and FST, whereas the environment factor explained most of the variation of AT and pH of aqueous extracts.