Reproductive Biology and Breeding Systems of Two Opisthopappus Endemic and Endangered Species on the Taihang Mountains

Opisthopappus is a perennial, endemic herb of the Taihang Mountains in China. Two species this genus (O. longilobus and O. taihangensis) are important wild genetic resources for Asteraceae; however, their reproductive biology has been lacking until now. This study first detailed report on breeding systems two species. Through field observations, floral syndromes taihangensis were found to possess similar pattern, although relatively larger capitulum, more ray ligules, disc florets. The flowers both protandrous, character that can prevent autogamy at single-flower level, insects required pollination. Further, brightly bisexual florets, unique fragrance, amount nectar suggest these propagate via an entomophilous pollination system. Hymenopteran Diptera observed as effective pollinators outcrossing index, pollen/ovule ratio results hand indicated might have mixed mating system combines cross-fertilization partial self-fertilization taihangensis, predominated system, while self-pollination played role seed production when insect was unavailable, particularly harsh environment, such cliffs. Meanwhile, better adapt severe surroundings with complex syndromes, specifically through attraction visiting high set rate. above not only provide reference information toward understanding survival strategies but also lay solid foundation further exploring molecular mechanisms underly adaptation under cliff environments.