Role of Salicylic Acid to Increase Systematic Resistance Against Phytoplasma in Date Palm Propagation From Tissue Culture.

Date palm is globally a significant economic crop, particularly in the Middle East. Throughout this inquiry, salicylic acid (SA) was used as inducer factor for phytoalexin to control phytoplasma disease. Phytoplasma was successfully transmitted using insect transmission protocol and confirmed by nested polymerase reaction (n-PCR). By using 0.3 and 0.6mg/l of SA as foliar application on the artificially infected date palms for 3 months; vegetative measures and phytoalexins (represented in biochemical changes in phenols and pigments) were assayed. Results showed that there were significant differences between control and date plams treated with 0.3mg/l and 0.6mg/l of SA in each of length of leaves, length of leaf's heart, diameter, phenol, Chlorophyll A, Chlorophyll B, and carotenoids content. While there were not significant differences between treated plants with 0.6mg/l and control treatment in number of leaves. Results of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) reported that infected plants and treated plants with 0.3mg/l of SA get 5 bands at 127, 119, 99, 65, and 52 KDa, and in treated plants with 0.6mg/l of SA and control plants get 3 bands at 127, 119 and 99 KDa. n-PCR referred to treated plants with 0.6mg/l of SA were recovered from infection of phytoplasma.