<研究報告>日本産ヌカボ属(イネ科)3 種の染色体数

概要

論文の詳細を見る
Chromosomes of Agrostis hideoi OHWI. A. valvata Steud. (syn. A. nipponensis HONDA) and A. scabra WILLD. were examined. Counts of 2n=14 (2x) were made in 13 collections of A. hideoi which is restrictedly distributed in Niigata Prefecture and neighbouring areas and has been examined cytologically for the first time. Counts of 2n=28 (4x) were obtained for 33 individuals in four populations of A. valvata, a species endemic in Japan. Seven populations of A. scabra distributed in Japan showed 2n=42 (6x), which is in accord with counts reported for the populations growing outside Japan. Interrelationships of these three species with other species of Agrostis were discussed on the basis of their cytological, morphological and phytogeographical attributes. The following estimations were presented : (1) A. hideoi with highly specialized spikelets and a restricted distribution area may have been derived from a A. hideoi-like plant, which is a diploid with less specialized spikelets and a wider range; (2) a taxon ancestral to A. valvata. a tetrapoid species, can not be found in the present day Japan Archipelago; (3) it seems most probable that A. scabra, a hexaploid species, originated in North America and extended its range up to Japan.
国立科学博物館の論文