De Novo Shoot Development of Tropical Plants: New Insights for Syngonium podophyllum Schott.

Syngonium podophyllum Schott. cv. 'White Butterfly' is recognized as a valuable ornamental plant, and today it is also an important plant species of medicinal interest due to its high contents of phenolic compounds. The purpose of this article is to review the main scientific publications from our laboratory with regard to new scientific achievements dealing with Syngonium species or topics of interest, such as callus formation and further de novo shoot regeneration. The principles and stages necessary to start an industrial-level micropropagation protocol are discussed based on our experience. Different media compositions induced different morphogenetic responses inside the callus—particularly those related to the development of xylematic elements in the organogenetic areas, such as those for rooting, protocorms, and de novo shoot formation. The re-evaluation of old histological images revealed for the first time that xylematic elements are constantly closely positioned to all organogenetic centers, and that their development is closely dependent on the composition of the culture medium. Separate protocorms can be identified only when xylematic tracheary elements are well developed and closely connected to them. The formation of protocorms is strongly dependent on the mineral composition of the culture medium and the balance of plant growth regulators. [ABSTRACT FROM AUTHOR]