Efecto de paclobutrazol en la densidad estomática y altura de Chenopodium quinoa

Abstract

Paclobutrazol (PBZ) is a growth retardant that, in addition to reducing plant height, may increase stomatal density and pore area. This research evaluated the effects of five PBZ concentrations on the number of stomata, stomatal pore area, plant height, and the visual appearance of Chenopodium quinoa cv. Suyana and Tunkahuan. The experiment was conducted from July to December 2024 at the Iztacala Faculty of Higher Studies, UNAM. Sowing was carried out in 50 pots containing 2.5 L of peat moss:expanded perlite (1:1). After 25 days, thinning was performed, and the following treatments were applied foliarly: 0, 25, 50, 100 and 200 mg L-1 of PBZ. Single-factor analysis of variance and mean comparison tests (Tukey, p≤ 0.05) were applied to the number of stomata and pore area. The results showed that the epidermal cells of both leaf surfaces had anticlinal walls with sinuous contours and anomocytic stomata. ‘Suyana’ had greater height (109.25 cm), more stomata mm-2 (98.4), and larger pores (21.28 μm2) than ‘Tunkahuan’. The application of PBZ increased the number of stomata and the opening of the stomatal pore starting at 25 mg L-1, and its effect was more pronounced at 100 or 200 mg L-1. PBZ also reduced the height of the plants and made them more colorful for possible ornamental use.