It can be applied regardless of species, moreover, is provided not to injure the unexpected chromosome of a chromosome other than to eliminate, easy aneuploid production method. Recognition sequences of one consisting of the nucleotide sequence of point symmetry, and or after, were introduced into a plant cell a vector comprising a recombinase gene, the two facing opposite directions or recognition sequence of two facing opposite directions After introducing into a plant cell a vector comprising a recognition sequence for the one having the nucleotide sequence represented by point symmetry or recognition sequence, in the cell, in the proliferation phase, was allowed to act transiently recombinant enzymes, the least grown by culturing cells and selecting cells that have lost the chromosome of interest.生物種を問わず適用することができ、しかも、消失させる染色体以外の染色体に予期せぬ傷害を与えることのない、容易な異数体作出方法を提供する。互いに逆方向を向いた二つの認識配列又は点対称の塩基配列からなる一つの認識配列、及び、組換え酵素遺伝子を有するベクターを植物細胞に導入した後、あるいは、互いに逆方向を向いた二つの認識配列又は点対称の塩基配列からなる一つの認識配列を有するベクターを植物細胞に導入してから、該細胞中で、少なくともその増殖時に、組換え酵素を一過的に作用させた後、その細胞を培養して増殖させ、所定の染色体が消失した細胞を選抜する。
