Disinfection of Orange Seeds to Reduce Citrus Canker Dissemination and Improve Germination

Abstract

We evaluated chemo and thermotherapy for decontaminating orange seeds against the bacteria Xanthomonas citri subsp. citri (Xcc), a quarantine and economically important disease worldwide. We infected orange (cv. Valencia) seeds with bacterial inoculum and studied the potential of three different methods i.e. surface sterilization with bleach, disinfection with plant preservative mixture, and hot water treatment to eliminate the bacteria. Our findings showed that the hot water, bleach (NaOCl), and a commercially available mixture of antifungal and antibacterial compounds known as Plant Preservative Mixture (PPM) were very effective in eliminating most bacterial contamination from orange seeds. Our results also showed that treatment with bleach and hot water treatment enhanced seed germination and seedling vigor. Germination rate ranged from 18.51 to 77.78%, 7.41 to 62.96% and 13.33 to 66.67% for bleach, PPM and hot water treatments, respectively. Seedling height ranged from 4.28 to 6.63cm, 4.17 to 5.94cm and 3.42 to 5.99cm for bleach, PPM and hot water treatment, respectively. Findings of this study will provide impactful and practical methods for an economical and robust seed decontamination method.