Clonal Propagation of Ziziphus spina-christi by Shoot Tip Culture: I. Improved Inorganic and Organic Media Constituents for in vitro Shoot Multiplication

Abstract

Cider is an important cultivated tree and one of the few truly native tree species of Saudi Arabia that is still growing along with many newly introduced exotic plants. The present study describes the influence of inorganic and organic media constituents on micropropagation of the Noaf variety, Ziziphus spina-christi. Shoot apices of 0.5 -1.0 cm were cut and transferred to a basal tested nutrient medium. The full concentration of M & S in this study yielded the best results in shoot length (3.02 cm) and number of leaves (1.80). No bud growth was observed in media devoid of sucrose. Shoot length, number of nodes and number of leaves were improved steadily with the addition of sucrose up to the concentration of 3.0% which showed a significant increase in all studied growth parameters. The full concentration of White's organics (1X), gave a significant increase in the shoot length (1.6cm) and number of nodes (2.4) over all other treatments. The bud growth of Cidir showed little response to the inositol treatment, since no significant difference in shoot length was observed between the control treatment (no inositol) and 1000 mg/L. The best adenine sulphate concentration that gave the best enhancment in most growth parameters was 80 mg/L. Shoot length (5.56 cm), number of nodes (6.7) and number of leaves (3.2) were enhanced by 1 mg/L charcoal concentration. This treatment was not significantly different from 2 mg/L treatment in shoot length and number of nodes although the 1 mg/L treatment showed a noticeable increase in these two parameters. Tissue culture application to the clonal propagation of "Cidir" will allow for the elimination of diseases and the rapid clonal production in large numbers of genetically identical plant material. The technique also greatly enhances the introduction of this variety (Noaf) and stimulates interest among nurserymen in Cidir cultivation as a fruit tree. Establishment of an in Mohammed A. Al-Sulaiman 4 vitro propagation scheme would enhance cloning of "Cidir", since propagules for future propagation can be derived from plantlets growing in vitro, and circumventing the requirements for explants from this sole stock plant available.