Grewia tenax is an important nutraceutical plant threatened due to excessive fruit collection and physiological dormancy of seeds. In vitro propagation is required for ex situ conservation of this neglected plant. Improving germination rate is vital for providing the uniform explant material required for propagation and in vitro studies. The aim of this study was to optimize cultivation conditions for in vitro seed germination and micropropagation of G. tenax. Full seed germination was achieved in all treatments. Tests in distilled water medium showed the least number of days for germination and highest seedling length. Full Murashige and Skoog medium produced the maximum number of nodes. Darkness promoted germination rate and seedling length, but decreased the number of nodes per seedling. Benzyladenine and kinetin slightly increased the number of nodes compared to the control. Each uninodal explant cultivated on Murashige and Skoog medium free of plant growth regulators developed into a plantlet within one week. Well-rooted plants were successfully established in a greenhouse with 95% survival rate. This plant growth regulator-free system can successfully overcome seed dormancy and provide a rapid-continuous supply of plant material of G. tenax.

Ornamental industry has applied immensely in vitro propagation approach for large-scale plant multiplication at very high rates of elite superior varieties. As a result, hundreds of plant tissue culture laboratories have come up worldwide. Dieffenbachia species are popular foliage potted plants used in interiorescapes of homes, offices, and malls throughout the world. Most of Dieffenbachia species are now propagated by tissue culture for better utilize of species and expedite plant improvement. This review paper summarizes valuable literature on in vitro techniques including type of explants used, media optimized, ways of propagation and improvement through 45 years of research on Dieffenbachia spp. Which were provide basis for future studies such as genetic transformation for breeding aims, develop new cultivars, develop disease-resistant plants and overcome the environmental obstacles. There is a need for more application of the plant tissue culture techniques on Dieffenbachia to investigate the responses of different cultivars and explants to variable culture media.