Morphological and polyamine content changes in embryogenic and non-embryogenic callus of sugarcane - Silveira, Vanildo; Vita, Aline Martins de; Macedo, Amanda Ferreira; Dias, Maria Fernanda Ribeiro; Floh, Eny Iochevet Segal; Santa Catarina, Claudete (Plant Cell, Tissue and Organ Culture, 2013)