Reproducible seeds are seeds from plants that are able to produce new generations of the same plant. This is true for open pollinated varieties. Most Heirloom seeds are open pollinated, hence reproducible. Hybrid and GMO seeds don’t produce plants with good reproducing seeds – also, hybrid and GMO seeds have patents on them from the seed-companies, hence are legally not allowed to be reproduced by farmers.
Hybrid seeds are bred by seed companies. With small brushes or similar tools, female parents are pollinated with male pollen. To avoid open-pollination, the parents grow in greenhouses. Through this controlled breeding, uniformity of fruits and vegetables in shape, color, high yield, disease or drought resistance and other characteristics is achieved. However, the seeds of these fruits and vegetables will not produce a good new generation of those plants.
Open pollination refers to the sexual reproduction of plants. Open pollination can either be through self-pollination or through pollen from a male parent which is carried to the female parent by insects, birds and wind. Since the breeding is uncontrolled and the pollen source is unknown, open pollinated fruits and vegetables usually vary in their appearance and strength. However, the seeds of these fruits and vegetables produce new generations of those plants.
An heirloom variety or heirloom vegetable is an old cultivar that has been saved across generations or across several decadesis by gardeners and farmers. The varieties may have been commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture. Some associations are preserving seeds of the older cultivars in seed banks. In the European Union, it is illegal to sell seeds of cultivars that are not listed as approved for sale. All heirloom varieties are usually open-pollinated.