The reduction in genetic quality of seeds resulting from self-pollination acts as a pivotal factor limiting the regeneration of the endangered plant Tetracentron sinense Oliv

Tetracentron sinense Oliv., an endangered relict species from the Eocene, primarily relies on self-pollination in nature. However, the impacts of self-pollination on seed quality, seedling viability, and population renewal remain unclear. In this study, we applied four pollination treatments (self-pollination, geitonogamy, xenogamy, and natural pollination) to the inflorescences of T. sinense. Subsequently, seeds from each treatment were collected and evaluated for their phenotypic characteristics and germination traits. We then conducted a five-month continuous monitoring of seedling survival, assessed their initial growth, and established a dynamic life table to track their development progress. Our findings revealed that self-pollinated T. sinense seeds exhibited inferior phenotypic traits, including decreased length, width, thickness, and 1000-grain weight, as well as lower germination rates and germination indices compared to seeds from the other pollination treatments. Furthermore, self-pollinated seedlings displayed shorter stems, smaller cotyledons, and reduced dry weights, but had longer taproots than cross-pollinated seedlings. They also showed lower survival rates and higher mortality rates than cross-pollinated seedlings. Analysis of the mortality density and hazard rate functions revealed a significant mortality peak and the highest failure risk at the two-month stage in T. sinense seedlings, indicating potential challenges during this period. In conclusion, our results indicate that self-pollination poses a significant threat to the survival of T. sinense by reducing seed genetic quality and seedling viability. Consequently, enhancing the genetic quality of T. sinense seeds through artificial cross-pollination could be a crucial strategy for promoting population renewal and supporting conservation efforts in the future.