From the FarmPlate glossary:
Open pollination means that a particular plant can be grown from seed season after season and will always come back “true to type,” or exhibiting the same qualities as the parent plant. Open pollination is facilitated by the wind, insect and animal pollinators or other natural mechanisms. It preserves and sometimes increases biodiversity. Many hybrid seeds do not possess this quality, and seeds saved from hybrid varieties may not produce the same fruit the following season if they germinate at all.