Histological and anatomical development of initiated adventitious buds from multiplied primary callus of Shwaithy date palm cultivar ( Phoenix dactylifera L.) in vitro

Abstract

The present study was conducted on apical buds of Shwaithy date palm cultivar to investigate effect of different “ MS” nutrient media , supplemented with α-naphthalene acetic acid “NAA” and isopentenyl adenine ” 2iP” on the stimulation of primary callus to produce organogenesis using tissue culture techniques . The anatomical study of the responded explants revealed the presence of special mechanism for the differentiation of the formed adventitious buds from the primary callus. The continuation of recapturing the primary callus on “MS” media, supplemented with 1 mg / l NAA and 3 mg / l 2iP, resulted in the development of meristemoids to meristems, distinguished by a large central nuclei (length : 100 µm and width : 25 µm). Further development of the cultured meristematic tissues led to either the formation of independent nodules with different size, shape and pattern of growth, or to become vascular bundles, or to be developed to produce adventitious buds. Transferring adventitious buds from stimulating MS media to multiplying MS media which was supplemented with 1 mg / l NAA and 4 mg / l 2iP induced further cell division in one direction, followed by more cell division in two directions , and this manipulation gained more cell division and multiplication in many directions and then to be initiated as adventitious buds. Development of adventitious buds was coincided with the formation of primordial roots and shoots and many vascular bundles which can be developed to become plantlets.