Heterospecific pollen interference has recently been proposed as a mechanism contributing to the success of alien invaders, as heterospecific pollen of alien plants can interfere with the reproduction of natives by reducing fruit and seed set. However, no study has looked at the opposite interaction. Moreover, few studies have considered the roles of phylogenetic and floral trait distances between pollen donors and recipients.

We did a large multi-species experiment in which we used alien and native species both as pollen recipients and as pollen donors, and included phylogenetic as well as single floral trait distance as explanatory variables.

We found that both alien and native recipients suffered from heterospecific pollen from donors of the opposite status in terms of seed and fruit set. Phylogenetic distance did not affect fruit and seed set. However, style-length distance decreased, while pollen-size distance increased heterospecific pollen interference.

We conclude that heterospecific pollen interference affects both native and alien recipients, thus indirectly altering community composition. Importantly, we found that heterospecific pollen interference can be a mechanism that increases biotic resistance of natives against invaders.

最近提出了异种花粉干扰作为促进外来入侵者成功的一种机制，因为外来植物的异种花粉可以通过减少果实和结实来干扰本地人的繁殖。但是，没有研究关注相反的相互作用。此外，很少有研究考虑到花粉供体和受体之间的系统发育和花性状距离的作用。

我们进行了一个大型多物种实验，在该实验中，我们将外来物种和本地物种既用作花粉接受者，又用作花粉供体，并将系统发生和单个花性状距离作为解释变量。

我们发现，在种子和果实结实方面，外来和本地接受者均遭受来自相反地位供体的异种花粉的侵害。系统发生距离不影响果实和结实。然而，花样长度距离减少，而花粉大小距离增加异种花粉干扰。

我们得出的结论是，异种花粉干扰会影响本地和外来受体，从而间接改变社区组成。重要的是，我们发现异种花粉干扰可能是增加本地人对入侵者的生物抗性的机制。