Seed quality and germination performance increase with cross-pollination in members of subtribe Orchidinae (Orchidaceae).

This article investigates the effects of autogamy (within-flower self-pollination), geitonogamy (within-plant self-pollination), and allogamy (cross-pollination) on fruit set, seed quality, and germination in 11 European orchid taxa of subtribe Orchidinae. The study found that while most taxa produced fruits after self-pollination, seed viability, embryo size, and germination rates were generally higher following cross-pollination, indicating significant inbreeding depression (ID) associated with selfing, especially geitonogamy. Seven taxa were confirmed as self-compatible, but seed quality from self-pollination was consistently lower than from outcrossing, suggesting that assessments of self-compatibility should include postfruiting viability and germination tests. The results emphasize the importance of cross-pollination for maintaining seed fitness and recommend its prioritization in orchid conservation efforts.