Contents of Embryo Factor in Developing Seeds of Datura and Lupinus (A. NATURAL SCIENCE)

1. In the seeds of Datura tatula and Lupinus, the content of embryo factor increases with the development of the seed. A rapid growth of the embryo occurs two or three days after a rapid increase of the factor. 2. The highest content of the factor is observed at the time of the most active growth of the embryo. 3. In the older seeds the content of the factor decreases, but in the fully mature Lupinus seed a considerable amount of it is found. 4. The embryo factor is found also in placenta and fruit coat of Datura and in pod of Lupinus. The authors are indebted to Prof. S. Imamura, Kyoto University, for his guidance and counsel during the course of this study

Some Factors Affecting the Growth of Young Embryo in Vitro (A. NATURAL SCIENCE)

1. For the growth of young embryos of Datura tatula in vitro, the optimum concentration of agar in the medium is 4.5g/l. 2. The optimum temperature is 35℃. 3. No effect of illumination of fluorescent lamps on the growth of the embryo is observed. 4. Embryos cultured on the agar surface of the medium develop the root more rapidly than those submerged in the medium do. 5. Among carbohydrates tested, sucrose is the best carbon source. Galactose, glucose, mannose, and raffinose are unfavorable. Fructose, lactose, maltose, mannitol, and xylose do not support the growth of the embryo. 6. The optimum pH value of the medium is 6.2. 7. Thiamine hydrochloride, riboflavin, para-aminobenzoic acid, folic acid, uracil, adenine sulfate, IAA, kinetin, and IAA-kinetin combinations have no growth-promoting activity in the young Datura embryo. A growth factor mixture (thiamine hydrochloride, pyridoxine hydrochloride, nicotinic acid, and glycine) added together with NH_4NO_3 is slightly effective. 8. Casein hydrolysate and vitamine- and salt-free one stimulate strongly the growth of embryo, peptone considerably, and tryptone and yeast extract slightly. Autoclaved DNA and RNA are rather inhibitory. The authors are indebted to Professor S. Imamura and Assistant Professor M. Hamada, Kyoto University, for their guidance and counsel during the course of this study

Growth-Promoting Factors in Young Lupinus Seeds (A. NATURAL SCIENCE)

1. The present study is concerned with cytokinin and embryo factor in young Lupinus seeds. 2. Partial purification of these factors was carried out. 3. The silver-precipitated fraction of the Lupinus extract stimulates cell-division of calluses of tobacco and carrot. It is promotive to the growth of radish leaf, and inhibitory to the degradation of chlorophyll of radish cotyledon. 4. Embryo factor and cytokinin in the Lupinus extract have different Rf values on paper chromatogram, indicating that they were different substances

Cytokinin Activities of Dihydrozeatin in Several Bioassays (A. NATURAL SCIENCE)

(±)-Dihydrozeatin was tested for its cytokinin activities in several bioassays and compared with different cytokinins. Dihydrozeatin stimulates the growth of tobacco callus at the concentrations of 10^-10^M with the optimum at 10^M, shoot development on tobacco callus at 10^M with 2×10^M IAA, the germination of lettuce seeds at 10^-10^M, the growth of radish leaf at 5×10^-5×10^M, and the development of lateral buds in pea seedlings at 5×10^M. This cytokinin inhibits the elongation of pea stem segment and delays senescence in detached wheat leaves at 10^-10^M. Dihydrozeatin is less active than zeatin and N^6-(isopentenyl) adenine (2iP) in these bioassays used, but it is of stronger activity than kinetin in the growth of tobacco callus and radish leaf and less effective in the germination of lettuce seeeds and the retention of chlorophyll

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)

Japanese Fungivoridae (Diptera) III : New or Little-known fungus gnats from the Tsushima Islands (Agriculture)

私たちは, 日本小島嶼の生物地理学的研究の一環として, 1959年7月対馬動・植物相の調査を行つたとき, 若干のキノコバエを採集することができた。従来, 本島産のキノコバエに関しては全く知見がないようであるが, ここに1新種及び1日本末記録種を含む5種が分布することを明らかにした。末筆ながら, 本調査に対してあたたかい御援助を賜わつた平安高等学校長近藤亮雅, 里内了徹両先生に厚くお礼申上げる

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

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