Sources and Concentrarions of Selenium in the Micropropagation of Sweet Potato

This study evaluated the effects of different sources and concentrations of selenium (Se) on growth, photosynthetic pigment content, accumulation of the element, survival rate after acclimatization, and genetic stability of sweet potato seedlings cv. Brazlândia-branca grown in vitro. Two independent experiments were conducted in MS medium supplemented with sodium selenate or selenite at concentrations of 0, 5, 10, 15, 20, and 25 µmol L ^- ¹. The variables analyzed included biometric characteristics, photosynthetic pigment content, Se accumulation in the aerial part and roots, ex vitro survival rate and genetic stability by nuclear DNA content by flow cytometry. Sodium selenate at concentrations of 10 and 15 µmol L ^- ¹ provided the best biometric results, pigmentation, and Se accumulation in the shoots. Sodium selenite stood out for its accumulation of Se in the roots, especially at 20 µmol L ^- ¹, and for its increase in pigments at 10 µmol L ^- ¹. Survival rates after acclimatization were high in all treatments, and none of the sources or concentrations of Se compromised the genetic stability of the seedlings. The application of 10 to 15 µmol L ^- ¹ of sodium selenate is recommended for the production of seedlings with better biometric and physiological performance, and 20 µmol L ^- ¹ of sodium selenite for root biofortification purposes, without compromising survival or genetic fidelity.