Spatiotemporal dynamics of pollen tube dormancy and ovule fate in Quercus dentata: A multimodal study of reproductive strategies.

This study investigated the sexual reproduction timeline of Quercus dentata, an ecologically important but understudied species. Using multiple microscopy techniques, we tracked female gametophyte development over its ∼150-day after pollination cycle. Key events include pollen germination (8 h after pollination), a pollen tube growth pause (7-17 days), fertilization (∼38 days), zygote dormancy, and mature embryo formation (∼78 days). Active detection and statistical analysis revealed an exceptionally high ovule abortion rate of 83.3 % per ovary; abortive ovules showed developmental failures, cellular degeneration, nutrients deficiency (low content of soluble protein, sugar, and starch) and metabolic disorders (low activities of SOD, POD and CAT, and low content of MDA). This study establishes a Q. dentata reproductive timeline, clarifies multidimensional ovule abortion mechanisms, and provides critical insights into the "conservation-divergence" of reproductive traits among congeneric species. The 83.3 % abortion rate and its associated characteristics, such as cellular degeneration and nutrient deficiency, help diagnose the drivers of ovule failure in other Quercus species. Importantly, the clarified ovule developmental/abortive patterns deepen understanding of plant reproduction. Moreover, its technical methods and identified key stages (e.g., pollen tube pause, zygotic dormancy and ovule abortive) provide valuable references for improving seed yield/quality in forestry, and offer valuable references for germplasm improvement and conservation strategies of endangered oak species.