Tag: pesticidal plants

Propagation of the medicinal and pesticidal tree, Bobgunnia madagascarensis is difficult due to poor and erratic germination of its seeds and slow growth of its seedlings. This study involved two separate experiments. The first evaluated the effect of pre-sowing treatments and growing medium on ex vitro seed germination and early seedling development. The second experiment involved in vitro germination, shoot initiation and rooting of shoots. Pre-sowing seed treatments involved soaking seeds in cold and hot water for 12 and 24 h and soaking in different concentrations (0, 100, 200, 400 and 800 mg/l) of gibberellic acid for 24 h. Soaking of seeds in cold or hot water for up to 24 h did not achieve more than 45% germination, while seeds treated with gibberellic acid achieved 76%) when seeds were sown in a growing medium without compost compared with a medium with compost (<43%). All shoot-tips isolated from the in vitro germinated seedlings on B5 media without plant growth regulators continued to grow as a single shoot, while shoot-tips cultured on B5 supplemented with 0.1 mg/l of naphthaleneacetic acid (NAA) and thidiazuron (TDZ) produced two shoots each after four weeks. It was concluded that B. madagascariensis seeds had very low ex vitro germination percentages. Although, in vitro cultures improved seed germination, axillary shoot multiplication and rooting were not satisfactory. Therefore, further studies are needed to develop an optimal in vitro multiplication protocol for B. madagascariensis.

Propagation methods do not exist for Securidaca longepedunculata. In this study, ex vitro and in vitro experiments were conducted to identify simple propagation methods for this species. Ex vitro germination rates did not exceed 43%, whereas in vitro procedures achieved 67 to 90% germination rates. In vitro germinated seedlings produced at least two re-sprouts and consistently showed vigorous growth. Explants cultured on B5 medium supplemented with indole-3-butyric acid (IBA) and 1- naphthalene-3-acetic acid (NAA) successfully produced roots within 4 weeks. It is concluded that germination of seeds, shoot multiplication and rooting of S. longepedunculata can be improved through appropriate in vitro procedures.