Abstract: | The Rumex acetosa L. in China possesses sex-chromosomes 2n=12A+XX in female plant and 2n=12A+XY1Y2 in male plant. The sex-chromosomes of male plant exhibit a chain of trivalent (Y1-X-Y2) in diakinesis of PMC meiosis. At metaphase Ⅰ, they make a V-shaped or a ring configuration. Some of them may form a XY-bivalent and a Y-univalent. Finally two kinds of reale gametes e.g. 6A+X and .6A+YY, are produced. Monoecious plant may be found in R. acetosa and has 22 chromosomes (22=18A+ XX+YY). This is a triplont with sterility. Cells with different chromosome number in the same plant have also seen in R. acetosa, and such plant never blooms in its life. |