かやつりぐさ科ノ染色體研究X. みやまかんすげノ異數體

抄録

Chromosome behaviour in meiosis of Carex multifolia OHWI has been investigated by 6 plants collected from 5 different localities. Three of them were diploid, having 30 chromosomes in the root tip cells, and the chromosome pairing in their meiosis has been normal. Of all of the rest three have been hypertetraploids; one of them collected at Mt. Kintokiyama in Sagami Province having 2n=64 chromosomes, second plant collected at Kamikuzu in Musasi Province having 2n=65 chromosomes, and the last collected at Ose in Kazusa Province having 2n=66 chromosomes. The investigation of meiosis of these three hypertetraploid plants has suggested that they were to be the derivatives of the autotetraploid (2n=60) which has already been found by OKUNO ('40). Chromosome pairing in meiosis of a plant with 2n=64 chromosomes has been normal; and this plant has been considered to be a secondarily balanced individual. While in the other twos chromosome behaviour in their meiosis have been accompanied by some structural hybridities, so they have been considered to be unbalancing derivatives of the tetraploid.
Thus in Carex multifolia 5 different somatic chromosome numbers, namely, 30, 60, 64, 65 and 66, have heretofore been found. It is interesting, that two steps of chromosome alterations, namely, doubling of the chromosome set and appearance of hyper- as well probably as hypotetraploids, have been found together within a species.