Alien pollen grains interfere with the reproductive success of native congener

Abstract

The effects of invasive species on native species comprise important conservation issues. Determining the mechanisms by which invasives exclude natives is indispensable to efficiently control their impact, but most invasives remain poorly studied. The purpose of this study was to elucidate potentially important but neglected mechanisms, reproductive interference, in wild Taraxacum systems, in which invasive Taraxacum officinale has displaced its native congener T. japonicum in Japan. Hand-pollination of mixed pollen grains significantly reduced the native seed-set compared to conspecificonly pollination. Moreover, natives with a high ratio of invasive pollen on their stigmas suffered severe seed-set reduction, and the proportion of invasive pollen on native stigmas increased as frequencies of the alien neighbor increased. These results, combined with those of previous studies, revealed that depositing invasive pollen on native stigmas contributes to the observed alien-frequency-dependent reduction of native seed-set, and strongly suggest that reproductive interference was the primary cause of displacement in the Taraxacum systems.

No Reproductive Interference from an Alien to a Native Species in Cerastium (Caryophyllaceae) at the Stage of Seed Production

“…For example, the native dandelion in Japan has been displaced by the alien congener, especially in urban areas. Our previous reports have described that the reproductive interference played a crucial role in displacement [6,7]. Similarly, reproductive interference has been suspected as an important factor of the extinction of the Japanese cocklebur, Xanthium japonica, in western Japan [8].…”

“…To assess the true universality of the phenomenon, it is necessary to consider publication bias [12], which occurs because researchers 2 ISRN Botany might not seek to report negative results and editors might not desire to accept such reports for publication. In fact, most published studies of reproductive interference have reported positive results only ( [6,7,13], but see [14]). To discuss the universality of the reproductive interference fairly, it is necessary to review not only the detection of the reproductive interference but also reports of its absence.…”

Two-Way but Asymmetrical Reproductive Interference between an Invasive <i>Veronica</i> Species and a Native Congener

“…Reproductive interference refers to any interspecific interaction that engenders the loss of the reproductive success in either or both interacting species. In plants, for example, heterospecific pollens have been known to interfere with ordinary insemination by conspecific pollens [10][11][12]. This is an extremely common mechanism affecting reproductive interference in plants.…”

Introgression and Long-Term Naturalization of Archaeophytes into Native Plants - Underestimated Risk of Hybrids

“…For example, there is much evidence that crops and other domesticated plants can hybridize with their wild relatives while still in cultivation (Ellstrand, 2003). Reproductive interference, which is the depression of fitness by interspecific pollination www.intechopen.com Introgression and Long-Term Naturalization of Archaeophytes into Native Plants-Underestimated Risk of Hybrids 49 interactions such as competition for limited pollinators and pollen loss by interspecific pollen transfer, has recently been recognized (Matsumoto et al, 2010;Takakura et al, 2011). In both phenomena, negative effects could become evident on the human timescale if a plant was cultivated extensively, such as agricultural crops.…”