Taeniophyllum aphyllum (MAKINO) MAKINO に関する研究花柄・根及び葉の構造(A. 自然科学)

Taeniophyllum aphyllum (MAKINO) MAKINO, one of the epiphytic orchids in Japan, was investigated morphologically. The mature root has dorsiventral structure and the under side adheres to the substrate with four-layered velamen. The cortex contains chloroplasts. The central cylinder is a typical root-form. The young plant has one leaf, which is triangular in cross-section, and the basal surface is adjacent to the substrate, while the other sides serve for assimilation. The epidermis is provided with stomata, which are similar in structure to those of the other orchid-plants. The epidermal cells and the vascular bundle of the leaf differ from those of the flower stalk or the root, but resemble those of the other orchids. The leaf has no hairs, and no velamen nor velamen-like tissue

Studies on the induced polyploids of the North American Pawpaws (I) : Chromosome number and mixoploids in Asimina triloba DUNAL

1. Asimina triloba DUNALの染色体は, n=8,2n=16と決定された。染色体は5型(a-e)に分類され, 各染色体の長い腕上には, 1個の狭窄が存在し, a型上にのみ, 2個の狭窄が見られる。b型には, 1個の附随体が存在する。2. 実生の腋芽に対するコルヒチン滴下処理により, 4倍体(2n=32)及び8倍(2n=64)体夫々1個が得られた。この2個体は, ミクソプロイドである事が認められた。2倍体, 4倍体及び8倍体個体の気孔の大きさは, 互に, 有意な差異を示し, 漸次, 8倍体に向つて, 巨大性を示してゐる。1. The chromosome numbers of Asimina triloba were determined as n=8,2n=16. The chromosome complement was classified into 5 types. The long arms of each type have a constriction and that of a type has two constrictions. The chromosomes of b type have a satellite. 2. By the colchicine treatment autotetraploid (2n=32) and auto-octaploid (2n=64) plants were obtained. These plants were shown to be mixoploids; in the leaf of tetraploid plant diploid numbered cells were found, and similarly, in the octaploid plant tetraploid numbered cells were found. The size of the stomata in the diploid, tetraploid and octaploid plants show significant differences from each other

日本産ラン科植物の染色体数(第 1 報)(数学及び自然科学)

Chromosome numbers are reported for 38 species and 4 varieties of the family Orchidaceae in Japan. Preparations were made from root tips by the modified squash method (Mutsuura and Nakahira, 1956). The results are summarized in table 1,in which 20 species and 3 varieties are reported for the first time. Chromosome numbers of 18 species and a variety are reconfirmed, but Calanthe reflexa (2n=42) is different from the previous number (2n=40). In the species of Calanthe tricarinata, one triploid plant (2n=60) is found

日本産ラン科植物の染色体数(第 4 報)(A. 理学)

Chromosome counts are made for 6 species, one forma and one variety in 8 genera of the family Orchidaceae in Japan. Preparations were made from root tips or buds by the modified squash method (Mutsuura & Nakahira, 1956). Chromosome numbers of Listera nipponica, Goodyera hachijoensis var. leuconeura, Oberonia Japonica forma major, Tipularia japonica, Liparis formosana, Phajus Tankervilliae and Bulbophyllum Makinoanum are reported for the first time, and the number of Calypso bulbosa is reconfirmed (Table 1)

日本産ラン科植物の染色体数(第 3 報)(自然科学)

Chromosome counts are made for 17 species of the family Orchidaceae in Japan. Preparations were made from root tips by the modified squash method (Mutsuura & Nakahira, 1956). Chromosome numbers of 14 species are reported for the first time, and those of 3 species are reconfirmed (Table 1,Figs. 1-2,Plate 1). We have found the 2n nu-nbers 18,20,24,46,48,56,60 and 64 in the Orchidaceae in Japan. Chromosome numbers of Habenaria Miersiana, Dendrobium moniliforme and Cymbidium virescens are different from those reported previously (Table 1)

Primula malacoides FRANCH. の細胞学的研究(数学及び自然科学)

17 garden varieties and their offsprings of Primula malacoides were studied cytologically. 13 varieties are found to be tetraploids, and 4 varieties, garden primroses cultivated from old, to be diploids (2n=18), and one to be a triploid (2n=27) (Table 1,Fig. 1). In meiosis of tetraploids 18II are shown, but pairing of bivalents is incomplete in general, and separation at anaphase is irregular in some varieties. Some of tetraploid offsprings are found to be aneuploids, somatic numbers being 34,35,37,38 and some of them have abnormal chromosomes (Table 2,3,Fig. 2). These offsprings are dwarf or male sterile, or have abnormal petals. So some of tetraploid varieties are assumed not to be genetically pure. Diploid varieties, on the other hand, exhibited regular meiosis, and chromosome numbers of their offsprings are normal. Triploid plants are found in the cross tetraploid×diploid

Taeniophyllum aphyllum (MAKINO) MAKINO に関する研究発芽及び幼植物の発育過程について(A. 自然科学)

In Kyoto, Taeniophyllum aphyllum (MAKINO) MAKINO is found to be growing on the trunks of several kinds of trees, especially on the underside of the branches of Cryptomeria Japonica. This orchid has several morphological characteristics unseen in other orchids. The young plant is a leaflike body and it grows very slowly. Observation was made on the growth of the young plants growing on the branches, especially, the earlier stage of the development was compared with that of the seedlings growing on a culture medium. The young plants grows to about 0.5mm in length in one year after germination, 1mm in 2 years, 1.8mm in 3 years, 2.9mm in 4 years, 4.5mm in 5 years, 7mm in 6 years, 9-12mm in 7 years, then the first root and the reduced leaf emerge at the end of the leaflike organ. This organ gradually shrinks and dies off after bearing about 7 roots. From the observation of tissues, it is assumed that the young plant of 3-7 years old is composed of a mixture of cotyledon and hypocotyl tissues