Mineral Requirements for Growth and Callus Initiation of Tissue Explants Excised from Mature Coconut Palms ( Cocos nucifera ) and Cultured in vitro

Abstract Growth of stem, leaf, and inflorescence explants from mature coconut ( Cocos nucifera L.) palms on a new mineral formulation (Y3) was superior to that on the minerals of White, Heller, or Murashige and Skoog. Cell division in the upper part of cultured explants gave rise to a layer of white callus within a month. The effects of omitting entirely or altering the concentration of individual elements in the Y3 formulation were investigated. It was concluded that growth on White's and Heller's minerals was seriously limited by deficiencies in macro‐elements, i.e. nitrogen (particularly ammonium), potassium and phosphorus, as well as micro‐elements, i.e. iron, iodine and molybdenum. The Murashige and Skoog formulation, on the other hand, was deficient only in certain micro‐elements (particularly iodine).