Estímulo sonoro altera características biométricas e morfoanatômicas de batata-doce in vitro

Abstract

Sweet potato (Ipomoea batatas L.) is a crop of significant agronomic and nutritional importance, widely cultivated in tropical and subtropical regions due to its rusticity and its important role in food security. Traditional vegetative propagation, as commonly used for sweet potato through vegetative cuttings, can favor the spread of pathogens. The use of biotechnological techniques, such as micropropagation, has been employed as an effective tool for obtaining healthy and uniform plantlets. Micropropagation is a technique carried out in fully controlled environments, which makes it possible to evaluate the use of different physical stimuli, such as sound, on plant growth and development. Sound, through its acoustic vibrations, can modulate physiological and structural processes in plants. This study aimed to evaluate the effects of sound stimuli (rock, classical music, and bird songs) and the absence of sound on biometric characteristics, photosynthetic pigments, and morpho-anatomical aspects of sweet potato plants cv. Campina grown in vitro. The experiment was conducted in a completely randomized design, with 14 replicates per treatment (rock, classical, and bird songs). Nodal segments were cultivated in MS medium and exposed to the sounds at 90 dB for 2 hours daily for 30 days. The variables evaluated were biometric (plant height, number of leaves, roots, nodes, and senescent leaves, stem diameter, length of the longest root, leaf area, fresh shoot and root mass, dry shoot and root mass), pigment contents (chlorophyll a, chlorophyll b, total chlorophylls, and carotenoids), and the comparison of leaf characteristics (trichomes and stomata) through scanning electron microscopy. The rock sound stimulus resulted in greater plant height, number of roots, nodes, and senescent leaves, as well as greater fresh and dry root mass, while leaf area was reduced. Chlorophyll and carotenoid contents did not differ among treatments. Morphoanatomical analyses revealed epidermal alterations under the rock sound stimulus, resulting in lower trichome density, with trichomes being larger and accompanied by stomata. In addition, the epidermal surface of these plants was more wrinkled. It is concluded that sound stimuli can influence biometric and morpho-anatomical characteristics of sweet potato plants, with rock sound being the treatment that presented the greatest number of significant differences compared to the control (absence of sound).