A review on factors affecting the Agrobacterium-mediated genetic transformation in ornamental monocotyledonous geophytes

• This review emphasizes the need to develop somatic embryogenesis protocols to assist genetic transformation of geophytes.
• The focus is on useful techniques employed on various plants and that can be applied in genetic modification of geophytes.
• Most research needs to be done to identify genes that can be expressed at functional levels.
• Methods such as gene transfer into pollen or seed and integration of new genes can assist in developing these plants.

Genetic improvement of ornamental geophytes especially the monocotyledonous type; is often restricted by failure of Agrobacterium to reach competent cells as well as a lack of efficient regeneration systems. Despite all these limitations, it has recently been shown that the use of efficient promoters, super-virulent strains, and the utilization of systems such as an agrobacterial monolayer, Agrobacterium-mediated pollen and seed transformation, floral dip method and sonication-assisted Agrobacterium-mediated transformation (SAAT) will ensure success in the genetic transformation of these ornamentals in the near future. This article outlines factors affecting transformation of monocotyledonous geophytes. Special emphasis is laid on measures that have been employed to alleviate various difficulties. The need to develop somatic embryogenesis protocols for the ease of transformation is highlighted. In addition, perspectives in view of future research are also given. This information is crucial for biotechnological improvement of ornamental geophytes that are proving difficult to transform.