Effect of Some Antioxidants, Auxins and Explants Type on Callus Initiation of Date palm cv. Bream

Abstract

This research was implemented in order to study some factors affecting callus initiation of date palm cv. Bream. Four explants; shoot tips, leaf primordia, axillary buds and mantel meriestems were used as an explants. To overcome browning, citric and ascorbic acids, as antioxidents and adsorbents including activated charcoal and polyvinylpyrrolidone (PVP) sterilized by autoclave or microfiltration were used. In the initiation stage, the effect of three plant growth regulators 2,4- Dichlorophenoxy acetic acid (2,4-D), Naphthalene acetic acid (NAA) and 4-amino-3,5,6-trichloropicolinic acid (Picloram) on callus induction from the four types of explants was studied using various concentrations (0, 25, 50 or 100 mg/L). Supplementation of 50 mg/l of each citric and ascorbic acid to the nutrient medium reduced of total soluble phenols to 0.009 mg/g of fresh weight . Results showed that the highest percentage of callus induction (53.12%) was obtained with MS medium supplemented 50mg/l picloram compared, with other auxins NAA and 2,4-D which were 37.5% and 28.12% respectively at the same concentration. Best explants response for callus induction were shoot tips (87.5%) compared with other. Picloram reduced the period required for callus induction 40 days compared with other auxins which was 63 days for 2,4-D and 59 days for NAA. Accordingly, these results can be adopted in the in vitro micropropagation protocols of date palm cv. Bream.