ABSTRACT

Root-knot nematode, Meloidogyne incognita (Kofoid and White) is one of most damaging pathogen of vegetables, including carrot (Daucus carota L.). We evaluated nematicidal potential of chitosan in combination with chopped leaves of Argemone mexicana L., Achyranthes aspera L., and Ricinus communis L. against infestation caused by M. incognita on carrot under both in vitro and in vivo. Infectious stage (J2s) and egg masses of M. incognita were exposed to different concentrations (2500, 2000, 1500, 1000, and 500 ppm) of chitosan and botanical extracts separately. Maximum mortality of J2s and the highest inhibition in egg hatching was observed at 2500 ppm of chitosan after 36 h and days incubation period, respectively and minimum found in 500 ppm of A. aspera after 12 h of incubation period. Furthermore, pots treated with 1 g chitosan and 30 g of freshly chopped leaves of all three tested botanicals significantly reduced pathological parameters and improved growth and photosynthetic attributes of carrot. In combination with botanicals, chitosan showed a synergistic effect against M. incognita on carrot as compared to chitosan alone. This study proves that chitosan's bio-efficacy, combined with selected three botanicals, could be utilised to manage M. incognita on the carrot as a potential sustainable treatment.

摘要

根结线虫，Meloidogyne incognita（类红线和白线）是最具破坏性的蔬菜病原之一，包括胡萝卜（Daucus carota L.）。我们评估了壳聚糖与切碎的Argemone mexicana L.，Achyranthes aspera L.和Ricinus communis L.切碎的叶子在体外和体内对胡萝卜根结线虫引起的侵染的杀虫潜力。传染性阶段（J2S）和卵块南方根结线虫分别暴露于不同浓度（2500、2000、1500、1000和500 ppm）的壳聚糖和植物提取物。在孵化36小时和几天后，分别在2500 ppm壳聚糖下观察到J2s的最大死亡率和对卵孵化的最高抑制作用，在孵化12 h后，在500 ppm的曲霉中观察到J2s的最大死亡率和最小孵化率。此外，用1 g脱乙酰壳多糖和30 g所有三种经过测试的植物切碎的新鲜叶处理的花盆均能显着降低病理参数，并改善胡萝卜的生长和光合特性。与植物药合用时，壳聚糖显示出对隐身支原体的协同作用与单独使用壳聚糖相比，在胡萝卜上的含量更高。这项研究证明，壳聚糖的生物功效，与选定的三种植物药相结合，可用于管理胡萝卜上的隐孢子虫，作为一种潜在的可持续治疗方法。