ABSTRACT

Durian (Durio zibethinus L.) is susceptible to Phytophthora palmivora, which causes rot disease, leading to significant yield loss. This study aimed to investigate local defense responses of durian to P. palmivora and compare the infection dynamics of high virulence (HV) and low virulence (LV) isolates. Durian leaves on 1-year-old seedlings were inoculated with mycelial plugs. Symptoms were observed within 24 h. The HV-isolate was more aggressive, leading to larger lesions, earlier and denser colonization, and higher sporulation. P. palmivora lifestyle related gene (PpEF1α, PpHmp1, PpCdc14, and PpOPEL) were expressed at a higher level in HV compared to LV. Local defense response showed intense accumulation of H₂O₂, with a stronger response to the HV. Callose deposition increased initially but declined after inoculation, with different diameters between isolates, but no significantly different intensity patterns. These findings provide insights into the P. palmivora-durian interaction, with potential applications in improving disease management strategies.

摘要

榴莲 ( Durio zibethinus L.) 容易受到棕榈疫霉的影响，引起腐烂病，导致产量严重损失。本研究旨在调查榴莲对棕榈假单胞菌的局部防御反应，并比较高毒力（HV）和低毒力（LV）分离株的感染动态。将一岁幼苗的榴莲叶接种菌丝塞。24小时内观察到症状。HV 分离株更具侵袭性，导致更大的病灶、更早且更密集的定植以及更高的孢子形成。P. palmivora生活方式相关基因（PpEF1α、PpHmp1、PpCdc14和PpOPEL）与 LV 相比，HV 中的表达水平更高。局部防御反应表现为H ₂ O ₂的强烈积累，对HV的反应更强。胼胝质沉积最初增加，但接种后下降，分离株之间直径不同，但强度模式没有显着差异。这些发现提供了对棕榈树与榴莲相互作用的见解，并在改善疾病管理策略方面具有潜在的应用。