An Effective Inoculation Method for Phytophthora capsici on Black Pepper Plants

Piper nigrum L. (black pepper) is a typical woody vine that is an economically important spice crop across the world. Black pepper production is significantly impacted by root rot disease caused by Phytophthora capsici, which has seriously influenced the industry development as a "choke point" problem. However, the molecular genetic mechanism of resistance in black pepper is unclear, leading to slow progress in the development of new black pepper varieties. An effective inoculation and precise sampling system for Phytophthora capsici on black pepper plants is essential for studying this plant-pathogen interaction. The main aim of this study is to demonstrate a detailed methodology where the basal head of black pepper is inoculated with Phytophthora capsici, while also providing a reference for the inoculation of woody vine plants. The basal head of the black pepper plant was pinpricked to damage it, and mycelial pellets covered the three holes to retain the moisture so the pathogen could infect the plant well. This method provides a better way of solving the instability that is caused by traditional inoculation methods including soil drench or root dipping. It also provides a promising means for studying the mode of action between plants and other soil-borne plant pathogens in agricultural precision breeding.