Inducing Somatic Embryogenesis in Grape (Vitis aestivalis ‘Norton/ Cynthiana’) Tissue Callus Derived from Ovary Explants

Abstract

The grape plant Vitis aestivalis “Norton/Cynthiana” is known for its hearty nature and low maintenance. However, this grape is also known for its poor propagation. Plant tissue culture is a method that has been used to propagate other recalcitrant species. Somatic embryogenesis in Vitis aestivalis has been attempted using callus generated from leaf explant tissue, but to date, has not been successful. The use of floral tissues has shown some success in other grape species, so the first goal of this research was to generate undifferentiated cell growth, or callus, from anther and ovary tissues of immature flower buds. Callus growth was successfully achieved using a Lloyd McCown basal nutrient tissue culture medium. Healthy callus tissue was quickly created from the ovary tissue, but callus was not immediately successful from the anther tissue. Anther explant tissues had to remain on the media for several weeks longer than expected before callus began to grow. The second goal of this project was to successfully generate somatic embryogenesis from callus. Both the anther and ovary callus were placed on embryogenic tissue culture media in an effort to promote embryogenesis. As Vitis aestivalis is not easily propagated, the embryogenic tissue media had to be carefully made and adjusted to find the exact mix of cytokinin and auxin concentrations that will lead to embryogenesis. In this project, no embryogenic response from ovary tissue on either the semi solid media or liquid suspension media was observed. Semi-solid media were shown to be good for regular maintenance of callus, but not embryogenesis. Liquid suspension culture also proved effective for callus maintenance, but not embryogenesis. The use of Murashige & Skoog basal salts seemed to advance callus growth in the liquid suspension media.