Restoration of a lost species: <i>Plantago fengdouensis</i> in the Yangtze River Basin, China

Abstract Plantago fengdouensis , a species endemic to China’s Yangtze River Basin, was once presumed extinct in the wild as a result of the complete inundation of its native habitats following the construction of the Three Gorges Dam. Historically documented only on two riverine islets in Fengdu and Zhongxian counties of Chongqing, the species was last observed in 2003 before its habitats were permanently submerged, leading to its designation as the first documented herbaceous plant driven to extinction by the dam project. However, in 2023 a previously unknown population of &gt; 200 individuals was discovered in Jiang’an County, Sichuan Province, representing the largest known wild population to date. From January to May 2023, 273 seeds were collected and conservation research was conducted in the botanical greenhouse of Yibin University. The key to the germination of P. fengdouensis seeds lies in the harvest period. Seeds with light brown seed coats that are not fully mature have the highest germination vitality. Through systematic germination trials, optimal conditions were identified as 24 h pretreatment with 1.0% gibberellin under 28 ℃ and 1,500 Lux illumination, achieving an 87.5% germination rate. During May–November 2024, nursery-grown seedlings were transplanted near the wild population, with an initial 89% establishment success and 98.5% survival after 12 months. These results suggest that P. fengdouensis populations can be effectively restored in situ through seed-based propagation, offering a model for conserving other threatened floodplain species.