Antonio Carrillo-Navarro, Alfonso Guevara-Gazquez, Margarita Pérez-Jiménez, Leonor Ruiz-García, and José Cos-Terrer
Margarita Pérez-Jiménez, Alfonso Guevara-Gázquez, Antonio Carrillo-Navarro, and José Cos-Terrer
The effects of carbon source and concentration and of seedcoat were tested on the in vitro germination of peach seeds derived from crosses performed in the field. Seeds were extracted from the fruit and cultured in Woody Plant Medium (WPM) supplemented with sucrose, glucose, or sorbitol at concentrations of 15, 30, and 45 g·L−1. The percentage of germination as well as the root and hypocotyl lengths were measured after the stratification process and before acclimatization. Seedcoat did not have any influence on seed germination in any tested media and genotype. Glucose at a concentration of 15 g·L−1 and sucrose at 15, 30, and 45 g·L−1 resulted in greater stem seedling growth. The root developed the most when seeds were cultured in media with 15 or 30 g·L−1 of sucrose.
Raquel Enedina Medina-Carrillo, Samuel Salazar-García, Jorge Armando Bonilla-Cárdenas, Juan Antonio Herrera-González, Martha Elva Ibarra-Estrada, and Arturo Álvarez-Bravo
In plants, secondary metabolites (SMs) have functions of both defense and adaptation to the environment in which they develop. In Mexico, ‘Hass’ avocado is cultivated in different climate types, so during its development, the fruit is exposed to extreme climatic factors, especially temperature and solar radiation. A recent study showed that the thickness and roughness of ‘Hass’ skin increased in the hottest climate. It is unknown how these factors affect the presence of SMs and lignin in the skin. The aim of this research was to quantify the concentration of total phenolic compounds (TPCs), chlorophylls, total carotenoids (TCARs), and lignin in the skin of ‘Hass’ avocado fruit over five developmental stages (S), based on fruit diameter [Olive (20–30 mm ø), S-I (35–45 mm ø), S-II (50–60 mm ø), S-III (60–70 mm ø) and Harvest (mesocarp dry matter ≥21.5%)], in three producing regions of Mexico: Nayarit (warm subhumid climate, elevation 1151 m), Jalisco (semiwarm, subhumid climate, elevation 2180 m), and Michoacán (temperate climate, elevation 1579 m). Both fruit developmental stage and producing region had a significant influence on the concentrations of SMs and lignin in the skin. During fruit development, the skin showed a decrease in the concentration of phenolic compounds (PCs) and an increase in the presence of chlorophylls, carotenoids, and lignin. The skin of fruit produced in regions with a semiwarm and temperate climate had higher production of lignin and PCs, as well as a lower concentration of chlorophylls.