Increase of the morpho-physiological responses of sugarcane plants in vitro (Saccharum spp. hybrids) using sodium silicate.

• Sodium silicate can be used as a bio-stimulant agent during the commercial micropropagation of sugarcane hybrids. • Silicon helps to increase morphological and photosynthetic pigments responses in sugar cane in vitro. • The stomatal index and stomatal occlusion are not altered with the application of silicon. • Acclimatization survival rate increases with the presence of silicon. Sugarcane (Saccharum spp. hybrids) is used as raw material in the agri-food and bioenergy industries. Plant tissue culture (PTC) allows production of many propagules in a relatively short time and limited space. Silicon (Si) is considered a non-essential element, and studies have demonstrated a positive impact on the development of plants obtained through PTC. This study aimed to evaluate the bio-stimulant effect of sodium silicate (Na 2 SiO 3) on the in vitro propagation of sugarcane (CP 72-2086 and Mex 69-290). Plant tips were established for each variety. The shoots obtained were then cultivated in an MS medium supplemented with different concentrations of Na 2 SiO 3 (0, 2.5, 5.0, and 10.0 mg L−1). After 30 d, morphometric analysis, quantification of photosynthetic pigments, and stomatal index measurements were performed. The results showed that 10.0 mg L−1 of Na 2 SiO 3 had a positive effect on the morphology of both varieties. The CP 72-2086 variety had a 0.5 number of shoots, 6.36 leaves and 5.8 roots more compared to the control. In contrast, the Mex 69-290 variety had more sizable proportion of shoot length (1.42 times), root length (2.20 times), and dry weight (1.33 times) compared to the control. However, 2.5 and 5.0 mg L−1 of Na 2 SiO 3 decreased the responses of variables evaluated in both varieties compared to the highest concentration. While the addition of Na 2 SiO 3 in both varieties had a bio-stimulant effect on the content of photosynthetic pigments. Results obtained suggest that Na 2 SiO 3 can be used as a bio-stimulant agent during the commercial micropropagation of sugarcane hybrids. [ABSTRACT FROM AUTHOR]