Effect of calcium and boron on growth and development of callus and shoot regeneration of date palm ‘Barhee’

Abstract

There are some major obstacles in practical applications of date palm tissue culture in the laboratory such as reduced number of shoots, vitrification of tissues, and browning of cultured tissues. The objective of the present study is to determine the effect of boron (B) and calcium (Ca) on enhancing organogenesis of buds from callus, shoot multiplication, and phytochemicals of in vitro cultures of date palm ‘Barhee’. Addition of calcium chloride and boric acid to the medium was most effective on callus for shoot regeneration and number of shoots per jar, where the best result (88.89%, 8.2 shoots per jar, respectively) was obtained by using 660 mg L−1 Ca + 9.3 mg L−1 B, compared with other treatments. It was observed that the interaction between 660 mg L−1 Ca + 9.3 mg L−1 B resulted in the highest tissue content of B [(4.75 mg L−1 dry weight (DW)]. The highest medium calcium chloride level (880 mg L−1) increased Ca content in the shoots. The combined application had the effect in reducing the vitrification. Application of Ca and B induced synthesis of proteins bands with molecular weights of 88.0, 55.6, 52.8, 43.0, 41.1, 38.3, 28.3, and 16.6 KDa in a medium supplemented with 660 mg L−1 Ca + 9.3 mg L−1 B.