90 per cent of an apple's bacteria are contained in its seeds. A single seed can contain up to 9,000 species of micro-organisms, including bacteria, fungi and archaea, numbering up to 2 billion individual microbes. A seed's storehouse of microbes start colonising its environement the moment it is planted. Microbes enter seeds maternally through the seed's outer coat, and paternally through grains of pollens or the stigma. They also come from the soil, and the guts of animals. --- Source: [[Soil]]