Self‐incompatibility and floral parameters in Hypochaeris sect. Hypochaeris (Asteraceae)

Abstract

We studied the relationships between self-incompatibility mechanisms and floral parameters in the genusHypochaerisL. sect.Hypochaeris(consisting ofH. glabra,H. radicata,H. arachnoidea, andH. salzmanniana). We assessed at intra- and interspecificlevels (1) the self-incompatibility (SI) mechanism and its distribution among populations, (2) the relationship between SI andfloral parameters, and (3) the relationship of SI to reproductive success.Hypochaeris salzmannianais semi-incompatible,H.glabrais self-compatible, andH. arachnoideaandH. radicataare self-incompatible. Floral parameters differed amongpopulations ofH. salzmanniana: plants in self-compatible populations had fewer flowers per head, a smaller head diameter on theflower, and a shorter period of anthesis than self-incompatible populations. We also detected this pattern within a semi-compatiblepopulation ofH. salzmanniana, and these differences were also found between species with different breeding mechanisms. Fruitto flower ratio in natural populations was generally high (.60%) in all species, regardless of breeding system. It is hypothesizedthat self-compatibility may have arisen through loss of allelic diversity at theSlocus due to bottleneck events and genetic drift