Propagation of Ornamental Plants
10(2): 93-98, 2010
IN VITRO PROPAGATION OF ADULT STRAWBERRY TREE (ARBUTUS UNEDO L.) THROUGH ADVENTITIOUS SHOOTS AND SOMATIC EMBRYOGENESIS
Mohamed El-Sayed El-Mahrouk1, Yaser Hassan Dewir1*, and Ali Mikael Kalifa Omar2
1Department of Horticulture, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt, *Fax: + 20473232032, *E-mail: ydewir@hotmail.com 2Department of Horticulture, Faculty of Agriculture, Omar Al-Mukhtar University, El-Beida, P.O. Box 911, Libya
Abstract
A method for induction of adventitious shoots and somatic embryogenesis (SE) of Arbutus unedo is presented. Semi-hard woody nodal segments were excised from adult donor tree (12 years old) and cultured for 6 weeks on Murashige and Skoog’s (MS) medium without plant growth regulators (PGRs) for the induction of axillary shoots. The induced axillary shoots were then cultured for 8 weeks on MS medium supplemented with TDZ (0-4 mg l-1) for their multiplication. The best axillary shoot multiplication (3.9 shoots/explants) was achieved on MS medium supplemented with 3.0 mg l-1 TDZ. Calluses were induced from internodal segments excised from in vitro axillary shoots and cultured on MS medium supplemented with various concentrations and combinations of PGRs. Embryogenic calluses developed over a period of 14 days with the highest response (17 embryos/callus) at 5.0 mg l-1 BA and 5.0 mg l-1 NAA. Following induction, the calluses were proliferated on the same medium and somatic embryos at the globular, heart-shaped, torpedo, and cotyledonary stages developed after 35 days in culture. Plantlets developed at 95% on MS medium without PGRs. Non-embryogenic callusses developed clusters of shoot buds. A combination of 2 mg l-1 BA and 0.5 mg l-1 NAA promoted the highest number of adventitious shoots (5.3 shoots/callus).
Key words: Arbutoidae, Ericaceae, in vitro culture, plant growth regulators, semi-hardwood cuttings
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