Study on fruit and seed morphology and morphometry, seed phytochemicals, and germination characterization in three populations of Echinocereus stramineus(Cactaceae) at Ciudad Juárez Municipality, Chihuahua, Mexico

Abstract

In this study, the fruit and seed morphological and morphometric parameters, the seed phytochemical content, and the germination process were analyzed for three populations ofEchinocereus stramineuslocated at Juárez Municipality, Chihuahua, Mexico. The morphometric variables were measured for each fruit and seeds obtained from each one.The seeds were subjected to three times of immersion in H2SO4as scarification treatment, allowing the seed development for 21 daysfor the characterization of the germination process. The germination percentage, mean germination time, germination speed, and mean germination speed were calculated. The seedling morphometry was also measured for all treatments. The concentration of reducing sugars, total phenols, tannins, flavonoids, andantioxidant activity (DPPH and FRAP) were determined for seeds under basal conditions. The fruits from the three populations showed significant differences in length and width, with the Sierra of Ciudad Juárez(SCJ)population having the longest and widest fruits.TheSCJ seeds had the highest mass values, while those from the Sierra of Presidio (SP)and SCP populations showed the highest length, length/width ratio, area, and perimeter. Immersionin H2SO4improved the germination percentage in SCJ and SP seeds. This treatment also caused a gradual decrease in the mean germination time and a progressive increase in the mean germination rate and germination speed index across seeds from all three populations as the immersion time increased. Similarly, the seedling stem length and area in SP seeds increased with immersiontime. The seeds from the SP population had the highest reducing sugar content, while those from the Sierra of Samalayuca (SS) population showed the highest levels of flavonoids, phenolics, tannins, and antioxidant activity