Self-Compatibility and Reproductive Success of Oenothera drummondii subsp. drummondii: Is It Similar between Native and Non-Native Populations?

Abstract

The mating system of plants widely distributed can change in native range but also in non-native habitats. Oenothera drummondii, native to the coastal dunes of the Gulf of Mexico, has been introduced to Europe, Africa, Asia and Oceania. Hand self- and cross-pollination were performed to determine compatibility and to compare fruit set, fruit weight, seed set and germination characteristics from natives and non-natives populations and a comprehensive integral reproductive success index (IRSI) was built. Oenothera drummondii exhibited high self-compatibility and mixed reproductive systems in all populations. Characteristics of fruits and seeds from self- and cross-pollination varied within and between native and non-native populations and some had a positive clinal variation in the native range. The IRSI was sensitive to changes of fruit set, seed set and final germination of both self- and cross-pollination, showing differences between native populations. Differences in characteristics of fruits and seeds in the native and non-native ranges suggest the occurrence of distinct selection factors. The mixed reproductive system of O. drummondii suggests it can take advantage of local visitors in the native range, but also can provide advantages for the establishment at non-native sites giving the opportunity to interact with local flower visitors.