(1) The crude leaf extract of different higher plants shows a remarkable activity of sulfite reduction with reduced-methylviologen. And the participating enzyme for this reaction is not precipitated by the centrifugation at 100, 000×g for 60 minutes. (2) The addition of phosphate buffer to this enzyme reaction system caused a marked decrease of activity but also caused the high degree of linearity of time course curve. (3) This sulfite reductase is more stable to heat than that from microorganisms. (4) Distribution of sulfite reductase in several higher plants was examined. (5) The reduction of sulfite by partially purified enzyme preparations with NADPH-generating system was observed. However, not only the crude extract but also the acetone treated fraction could not reduce sulfite with the system mentioned above. The author wishes to express his sincere gratitude to Prof. R. Sato in Osaka University, under whose guidance this study has been carried out. Thanks are also due to Prof. M. Akino and Prof. M. Hasegawa in Tokyo Metropolitan University for their valuable criticism and for reading the manuscript.
Daily measurements were made on the contents of acid-soluble ester phosphorus and inorganic phosphorus in the shoots of rice and oat seedlings grown in the dark without nutrient supply. In both rice and oat shoots the ratio of ester P to total acid-soluble P is high at the initial growth stage but falls as the growth proceeds. While the concentration of inorganic P increases with time, the ester P concentration declines in a first few days to a low level. Total acid-soluble P content per shoot or per dry weight was higher in oat than in rice, but this was not the case on the wet weight basis. A difference between rice and oat is noticed in the ester P level at an early period of growth. The author wishes to express his thanks to Professor Joji Ashida of Kyoto University and Professor Hideo Hamada of Hyogo University of Agriculture, for their valuable suggestion and encouragement. The oat seeds were kindly supplied by the Agricultural Experiment Station of Hokkaido University, and the rice seeds by Iwate Agricultural Experiment Station.
1. The effects of nitrogen compounds on the growth of the young embryos of Datura tatula were investigated in vitro. 2. NH4N03 was the most excellent nitrogen source and KNO3, NaNO3, (NH4)2HP04, NH4-succinate, L-glutamine and L-cystine were fairly good. 3. Seitz-filtered NH4NO3 was a little more stimulative than autoclaved one. 4. The better growth was observed on the NH4NO3 medium autoclaved at pH 7.2 than at any other pH values. 5. The optimum pH value of the NH4NO3 medium after autoclaving was 6.2. 6. When embryos were cultured on the media at lower concentration of NH4NO3 and various osmotic values, their growth values increased with increasing osmotic value, and the maximum growth was observed at the osmotic value equivalent to 0.06M NH4NO3 medium. On the other hand, at constant osmotic value the growth value was almost the same at higher concentration of NH4NO3 as at 0.0075M. 7. On the NH4NO3 medium, growth values of embryos at four different ages decreased hyperbolically with advancing age. Nearly mature embryos showed approximately the same growth value on both media with and without NH4NO3.
In order to clarify the annual net production and the nutrient element circulation in montane grassland, especially of Miscanthus sinensis type and Arundinella hirta type, a series of investigations were carried out during three years (1959-1962) in Kirigamine grassland (1600-1800m above sea-level), Nagano Prefecture, central Japan. The present paper, as the first report of this series, deals with the climate, soil and vegetation in Mt. Kirigamine. 1. The temperature climate is fairly cool (" warmth index" by Kira is about 48°), compared with other montane grassland in Japan. Growing period of herbs in this grassland is six months from May to October, and average duration of snow cover is about four months from mid-December till mid-April. 2. The soil in Kirigamine grassland was mostly originated from volcanic ashes and was very rich in humus content. Content of nitrate nitrogen was found to be very scanty both in Miscanthus-type and Arundinella-type stand. The soil in the latter stand showed lower calcium content and less- developed granular structure of soil particles than in the former one. 3. The relationship between vegetation and topography (exposure or steepness of slopes) was clarified by studying the distribution of each vegetation type in Mt. Kirigamine (Figs. 1 and 2). Sasa nipponica-type communities mostly dominated ongently south-facing slopes and on hill tops, or on such places as exposed to the prevailing south wind in winter. While Miscanthus-type and tall-herb-type communities occurred mainly on north-facing slopes. Further investigations with the belt-transect method revealed a close relationship between vegetational distribution and depth of snowdrift and of frost penetration in winter period. Miscanthus-type and tall-herb-type communities were distributed predominantly in sites where soils were protected against freezing under insulating snow cover more than 1 m deep, while Sasa-type communities occurred in sites where snow cover was very thin and frost penetration was more than 10cm. The thickest A-horizon was observed in the tall-herb type stand (about 90cm) and the thinnest in the Sasa-type stand (about 50cm). 4. Maximum above-ground biomass was estimated in late August in dry weight to be 190-240g/m2 for Sasa type, 210-260g/m2 for Arundinella type and 460-500g/m2for Miscanthus-tall-herb-type communities.
Several antibiotics were found useful to get bacteria-free crown-gall tissue of sunflower. Aureornycin, penicillin and vancomycin were most effective. Mycostatin was used at the same time as a fungicide with the above bacteriocides. Shake culture was more suitable than agar culture for this treatment.