Manipulations of endosperm balance number overcome crossing barriers between diploid solanum species.

Abortion of the hybrid endosperm is the basis for the inability to hybridize many angiosperm species. This has made it nearly impossible to incorporate the valuable characteristics from several wild, diploid Solanum species into the cultivated potato Solanum tuberosum. But some wild species have "endosperm balance numbers" different from those of most Solanum diploid species, and these numbers or "effective ploidies" can be manipulated to create new hybrids.