Optimization of in vitro culture conditions affecting propagation of mulberry plant

Abstract

Abstract Background Mulberry Morus spp. L. Family Moraceae is a perennial tree crop cultivated worldwide for foliage, fruit, fuel wood, and medicine, as well as for several other sericulture and industrial purposes. Mulberry trees are grown in more than 50 countries covering temperate, subtropical, and tropical zones as a plantation crop. Methodology In this study, different stages of in vitro propagation mulberry plant were investigated. In the sterilization stage, different concentrations 0.1, 0.2, and 0.3 (%) of mercuric chloride (MC) for 10 min were used. Also, the effect of supplementation of the Murashige and Skoog (MS) medium with different concentrations 0, 0.5, 1.0, and 1.5 mg/l of BAp or TDZ on the multiplication stage was investigated. Moreover, the impact of the fortified MS medium with 1 mg/l IAA or NAA or IBA on enhancement of root system proliferation was studied. Furthermore, the effect of reculturing in vitro derived plantlets on peatmoss, perlite, and/or vermiculate for in vivo acclimatization and hardening was investigated. Results A simple and efficient protocol for in vitro propagation of different varieties of Morus alba (yue 11, sha 2x lun 109, morittina, kokuso 27, and kantava 2) was established. Sterilization of shoot tips and auxiliary buds with 0.2% of mercuric chloride (MC) for 10 min was the best to get sterilized and survival explants. In vitro mulberry multiplication of yue 11, sha 2x lun 109, morittina, kokuso 27, and kantava auxiliary buds cultured on the MS medium fortified with 1.5 mg/l BA gave the best results of the multiplication rates, maximum number of shoots/explant, and highest shoot length (cm), respectively. Moreover, culturing of derived mulberry shoots on the MS medium supplemented with 1 mg/l NAA enhanced totally growth figures of root system formation suitable for acclimatization and hardening of in vitro derived mulberry plants. Acclimatization and hardening successfully processed with canava 2, morittina, yue 11, sha2x, and kokuso of mulberry cultivars, respectively. Conclusion The described protocol in this investigation ensures a round-the-year in vitro propagation of mulberry plant with faster rate of multiplication of true-to-type plants, which will provide a useful tool for large-scale multiplication of other mulberry varieties.