Micropropagation of date palm cv. malakaby through somatic embryogenesis 3- effect of tryptone, yeast extract, casein hydrolysate and pineapple extract

Date palm (Phoenix dactylifera. L.) dry cultivar, i.e. Malakaby repetitive somatic embryos clusters cultured on MS (Murashige and Skooge, 1962) modified medium (MMS) supplemented with NAA (0.1 mg/I), kin (0.5), activated charcoal (1.5 g/l) and gelrite (1.5 g/l) in addition to tryptone at the concentration of 1.0 g/l recorded higher significant number of embryos and multiplication rate, also higher fresh weight and growth value. However, addition of yeast extract at the concentration of 1.5 g/l recorded higher significant number of embryos as well as higher embryos multiplication rate, fresh weight and growth value. Also, addition of casein hydrolysate at the concentration of 1.5 g/l recorded higher significant number of embryos as well as higher embryos multiplication rate, fresh weight and growth value. While; addition of pineapple extract at the concentration of 9 g/l recorded higher significant value of all growth characters as compared with the control. Resulted shootlets were cultured individually on MS basal medium supplemented with NAA 0.5 mg/1and IBA 0.5 mg/1 in addition to the same chemical compounds concentrations previously tested and solidified with 6 g/l phyto agar. Well- rooted plantlets obtained were transferred ex vitro for acclimatization on soil type mixture of compost and perlite (1:1 v/v). Addition of tryptone at the concentration i.e. 1, 1.5 and.2 g/l to the tooting medium decreased all morphological characters after 8 weeks of incubation and declined plantlets survival (26.67, 13.33 and 6.67 %) respectively compared to the control (40 %) after 3 months in acclimatization. However, addition of yeast extract at the concentration of 1.5 g/l to the rooting medium recorded higher no. of leaves, leaf length, no. of roots and raised survival in acclimatization (26.67 %) over the control. While, addition of casein hydrolysate at the concentration of 1.5 g/l to the rooting medium recorded higher significant values of number of roots and raised survival in acclimatization (13.33 %). On the other hand, addition of pineapple extract at the concentration of 9 g/l to the rooting medium recorded higher values of all growth characters and raised plantlets survival in acclimatization (33.33 %) over the control.