A method of producing highly fertile autotetraploid counterparts of rye varieties
Kobylyanskii, V.D., 1979: A method of producing highly fertile autotetraploid counterparts of rye varieties. USSR Patent: (689644)
This technique involves doubling the chromosome number in diploid varieties and then producing highly fertile autotetraploids by pollinating the induced tetraploids with pollen from the initial variety which carries unreduced gametes.