High-frequency Regeneration of Shoots from Cotyledon and Leaf Explants of a Medicinal Cucurbit, Mukia maderaspatana (L.) M. J. Roem.

摘要

The purpose of this study was to develop an efficient protocol for in vitro organogenesis from cotyledon and leaf explants of Mukia maderaspatana (Linn.) M. J. Roem., a medicinal member of the family Cucurbitaceae. Cotyledon explants isolated from invitro germinated seedlings (5-6 days old) were cultured on Murashige and Skoog (MS) medium containing different concentrations of 6-benzyladenine (BA; 0.89, 1.78, 2.22, 3.11, 4.40 and 6.62 mu M) alone, or in combination with indole-3-acetic acid (IAA; 0.57 muM). Cotyledon explants cultured on medium containing BA (2.22 mu M) and IAA (0.57 muM) induced a significantly high number of multiple shoots (9.00 +- 0.60) with increased mean shoot length (2.70 +- 0.10) within 5 week of culture. Leaf segments fromin vitro grown plants (20 days-old) were cultured on MS medium with different concentrations of BA (0.22, 0.44, 0.89, 1.78, 2.22, 3.11 and 4.40 muM) alone, or together with IAA (0.57 muM). Maximum number of shoots (10 +- 0.75) with increased mean shootlength (2.90 +- 0.12) were obtained directly from leaf explants (without intervening callus phase) using a combination of BA (0.89 muM) and IAA (0.57 uM) within 5 weeks of culture. Inclusion of IAA to MS medium with BA triggered 80% of regeneration fromleaf and cotyledon explants. Elongation of regenerated shoots occurred when cotyledon cultures (3 weeks-old) were transferred to MS basal medium. Leaf cultures with emerging shoots were sub-cultured onto the same treatment medium for further elongation.The elongated shoots (2-3 cm) were excised and rooted on MS medium supplemented with IBA (2.46 mu M). Rooted plants were acclimatized in the greenhouse with a 70% survival rate.