ピーマン種苗の放射線感受性(農学部門)

ピーマンについて, 遺伝的雄性不ねん系統の作出など人為的突然変異誘起の手段としての放射線照射を効果的に行なうためにまずその感受性を調べた。種子照射の場合の生育限界線量はX線で30kr., ガンマー線で50kr.であり, (LD)_はそれぞれ20∿25kr.および40∿50kr.である。苗に対するXさ照射では2kr.が限界線量と考えられ, また1kr.の照射で約15日後にほぼ完全な不ねんをひき起こす。目的とする突然変異の誘起には上記の範囲の線量での照射が効果的であると考えられる。The study of radiosensitivity is important as the first step in plant breeding by radiation. The present study was carried out to investigate the radiosensitivity of dry pepper (Capsicum annuum L.) seeds and young pepper plants exposed to X- or gamma-rays. Philips deep therapy unit was used for X-irradiation and radiocobalt was used as the source of the gamma-ray. The irradiated seeds were sown immediately. Germination of the irradiated seeds was inhibited by high dosage. All of the seedlings, furthermore, were killed by35kr. of X-ray or 60kr. of gamma-ray. (LD)_ in pepper seed is considered to be 20-25kr. of X-ray and 40-50kr. of gamma-ray. For the young plants, 1-2kr. X-irradiation was the most effective, and almost all pollen grains were made abortive by 1kr. irradiation while growth promoting effects were observed at 0.25-0.5kr. irradiation

深耕多肥密植栽培における水稲群落の微細気象と productive structure(農学部門)

栽植密度, 耕深および施肥量の相違により, 水稲群落における微細気象とproductive structure(生産構造)がどのように変化するかを検討するために, 1961年に中生新千本を用いて実験を行なつた。主な結果は次のとおりである。1)個体の生育経過はすでに報告されているものと傾向を一にする。すなわち, 密植にするほど草丈は低く, 一株当たり茎数は少ない。さらに最高分げつ期, 出穂期に達するのが早い。一方, 深耕条件では有効茎歩合が高く, 根は深い部分にまで分布する。2)深耕多肥密植条件下の水稲群落内の微細気象は概して高温多湿である。3)深耕多肥密植栽培における水稲群落のproductive structureは, 標準栽培のそれと比較して次のような特徴を示す。すなわち, 全乾物重は増加し, また非同化部分にくらべて同化部分の量はやや多いが, 同化部分のうちでは下位における発育が乏しく, その光合成機能は上位葉に依存する体制にある。これは主に植物の相互遮蔽に影響される受光条件の差異によるものと考えられる。4)深耕多肥密植栽培では標準栽培より一穂当たり粒数が少なく, 不稔歩合が高く, 単位面積当たりの収量も少なかつたが, これは成熟期における台風・日照不足などの気象の悪条件によるものと思われる。In this experiment conducted in 1961,the authors examined how the microclimate and the productive structure in rice plant communities were influenced by various combinations of plant spacing, depth of tillage and amounts of manure. The rice variety named Nakate-Shinsenbon was used. Main results were summarized as follows : 1) On the individual plant, the vegetative growth, as already reported in the previous papers, generally reduced under the all conditions with thick spacing in spite of degree both of tillage and manure. Moreover, the days from germination to full tiller period and to heading period were both shortened under same conditions. Under the conditions with deep tillage, however, percentages of fertile ears per hill and root length were almost increased. 2) Microclimatic conditions, i. e. temperature and moisture in plant communit es under the condition combining with thick spacing, deep tillage and heavy manuring (plot 7) both exceeded those under the ordinary condition (plot 2). This tendency was observed throughout the whole generative growth periods; especially in August it was most striking. 3) The productive structure of plant communities were such as shown in Figs. 6 and 8,the dry weight of top and of assimilative parts per unit area increase of plant density. But as the density increases, percentages of assimilative parts or vigorous leaf-blades at lower parts of plant somewhat reduced. It might be said that photosynthetic abilities of plants under the conditions with thick spacing mostly depended upon the leaves of upper parts, and the phenomenon was due to the differences in conditions of receiving the light, which was greatly influenced by the mutual shade among the plants. 4) Plants under the ordinary condition were remarkably superior in number of grains per ear and percentages of fertile grains to those of the condition combining with thick spacing, deep tillage and heavy manuring. Consequently, decrease of yield per unit area appeared in latter condition compared with the former ones, and this reduction seemed to be promoted by the typhoon and the clouded weather in ripening stages in this year

トウガラシの種間雑種の台木としての利用について(農学部門)

カリフォルニアワンダー, 紫トウガラシおよびブラックプリンス(以上Capsicum annuum)にボリビアで採集されたNo. 3341 (C. chinense)を交雑した種間雑種, ならびにブラックプリンスの台木としての利用の可能性について検討した。つぎ穂には, ししとう(C. annuum)を用いた。台木の各品種とつぎ穂ししとうとの, つぎ木活着率はすべて100%であり, つぎ木後も順調に生育し, つぎ木不親和は認められなかった。No. 3341とカリフォルニアワンダーおよびブラックプリンスとの種間雑種ならびにブラックプリンスを台木とした場合には, 青枯病抵抗性および果実収量に問題があり, これらは台木用品種としては不適当と思われる。紫トウガラシとNo. 3341との種間雑種は, 生育が非常に旺盛であり, 青枯病に対し抵抗性をもっている。本品種を台木として用いた場合には, つぎ穂の生育, 果実収量その他に問題はなく, トウガラシ栽培の台木用品種として有望と思われる。Interspecific hybrids, Capsicum annuum cv. California Wonder×No. 3341 (C. chinense, introduced from Bolivia), C. annuum cv. Murasaki×No. 3341,C. annuum cv. Black Prinec×No. 3341 and \u27Black Prince\u27 were examined for their usefulness as rootstock in \u27Shishito\u27 (C. annuum, green pepper) growing. The scion showed no grafting incompatibility with all the rootstocks tested. Use of \u27Murasaki\u27×No. 3341 which is characterized by bacterial wilt resistance and vigorous growth, as the rootstock resulted in superior growth and yield of the scion \u27Shishito\u27. \u27Califolnia Wonder\u27×No. 3341,\u27Black Prince\u27×No. 3341,and \u27Black Prince\u27 failed to prove usefulness as the rootstock from the view point of fruit yield and bacterial wilt resistance. From these results it is concluded that \u27Murasaki\u27×No. 3341 has a potential for use as the green pepper rootstock

水稲移植操作の省力化に関する研究 I : 苗を横たえた場合の生育相の変化(農学部門)

水稲移植操作の単純化をはかるための1方法として, 苗を地表面に横たえることに注目し, その場合の水稲の生育相を, 苗を直立させたときのそれと比較検討した。実験は1963年に新山吹を供試して行なった。主な結果は次のとおりである。1)横植栽培をした水稲の生育相は, いわゆる後期凋落の傾向を示す。すなわち, 初期生育は旺盛であるのに反し, 後期生育はむしろ直立植栽培(普通栽培)がまさる。2)横植えにすると, 初発分けつの発生節位が低く, 各次分けつの発生時期が早い。分けつ茎の総数は常に多いが無効茎となる割合も高い。無効分けつとなるものの多くは3次分けつである。3)横植えにした稲では, 根の乾物重および生葉面積の生育初期における増加が大であるが, 出穂期前後から減少して, 直立した稲に及ばなくなる。4)単位面積あたり玄米重に有意の差はないが, 横植えのほうがやや多く, 収量構成要因からみれば, 穂数は多いが登熟歩合が低下する。The experiment was carried out to make clear the effect of different transplanting methods on the growth habit of the rice plant. Two methods, i. e., planting the seedlings in the horizontal direction and in the vertical directoin (normal method) were examined. Main results are summarized as follows : 1) In the horizontal planted plot, total dry weight, tiller number and leaf area per hill increased rapidly at the early stages of growth, and remarkably decreased at later stages of growth, in comparison with those in normal planted one. 2) In the horizontal planted plot, the first primary tiller appeared from lower node on main culm of plant. Moreover, each primary, secondary and tertiary tillers commenced to develop earlier than those in normal planted plot. Active tillering of plants at the early stages of growth in the horizontal planted plot was followed by a remarkable decrease in tiller number after the maximum tiller number of stage; this resulted in a low percentage of effective tillers. 3) Generally, in the horizontal planted plot, the panicle number increased and the percentage of filled grains decreased. 1,000-grain weight was about equal in both plots. Grain yield was slightly increased in the horizontal planted plot as the results of combining the yield components mentioned above, but the difference of yield between the plots was not significant at the 5% level

水稲移植操作の省力化に関する研究 II : 横植栽培水稲の窒素追肥時期と収量との関係(農学部門)

先に, 横植栽培をした水稲の生育相はいわゆる後期凋落の傾向を示すこと, そしてこの後期生育の衰退を防ぐには, 施肥量・施肥時期などについての考慮が必要なことを報告した。本報では, 横植栽培水稲の施肥について, 主として窒素の追肥時期と収量との関係を構成要因別に分析し, 追肥による収量増加の可能性を検討した。主な結果は次のとおりである。1)穂首分化期ごろ(出穂前33日)の追肥は, 登熟歩合の減少をきたし収量はあまり多くない。2)減数分裂開始期直前ごろ(出穂前18日)に追肥をすると, 登熟歩合の低下が目立ち, 収量は最も低下する。3)出穂直後(出穗後2日)に追肥をした場合は, 最も高い収量を示すが, これは登熟歩合の向上にもとずく。4)一般的にいって横植栽培では, 出穗直後の追肥は登熟歩合を著しく高め収量増加に効果的である。The experiment was carried out to make clear the effect of top-dressing on the yield of rice plant, of which seedlings were transplanted horizontally. The nitrogenous fertilizer (urea) was top-dressed at the three different stages of the plant growth, that is, at the stage of neck-node differentiation (33 days before the heading), just before the reduction division (18 days before the heading) and just after the heading. These different stages will be described hereinafter as the first, second and third fertilizing stages. The top-dressing in the first and second stages brought respectively the reduction of the grain yields per unit area (g/m^2). It was mainly due to the fall in the percentage of ripened grains. The highest yield was obtained in the case of the third top-dressing. This can be ascribed to the increase of the percentage of ripened grains, in contrast to the other cases. Generally speaking, in the horizontally planting of rice plant, the top-dressing with nitrogen was proved to be the most effective just after the heading stage

鶏の消化率測定法としての人工肛門法と化学的分離法との比較(農学部門)

鶏に対する簡単な消化率測定法としてEkmanらによる糞中窒素定量法と糞中有機物量の算出に片山の係数を応用して無手術鶏の糞尿混合排泄物から直接消化率を求め, 現在一般化されている人工肛門法と比較してその実用性を検討した。試験はロック・ホーン大びな雄の人工肛門設着鶏と無手術の正常鶏各3羽づつを用い, 低繊維含量の飼料で2回, 高繊維含量の飼料で1回, 計3回行なった。いずれの試験においても粗繊維以外の各成分の消化率には両法の間に差異はなく, 粗繊維の消化率のみ常に人工肛門法の方が高い値を示した。しかし粗繊維に関しては正常鶏で得られた消化率が正しい値を示すはずであるから, 定量操作が簡単なEkmanらの糞中窒素定量法と片山の係数を応用する消化率測定法は, 対象とする鶏の年令を問わずしかも随時に消化率を求めることができる実用性の高い簡便な方法であると考える。A method of chemical separation (chemical method) as a convenient procedure of determining the digestibility of the fowl was compared with the artificial anus technique. Six S. C. White Leghorn ♂×Barred Plymouth Rock ♀ cockerels, averaging 2.1kg, groups of three cockerels with the artificial anus and three normal cockerels with the intact anus were used in each of three digestion trials. In trial 1 and 2 digestibility were compared with cockerels fed low-fiber ration (3.3% and 4.2%) and in trial 3 with cockerels fed high-fiber ration containing the 13.7% crude fiber. In the chemical method, of the components in the mixed excreta crude protein content was determined by using the direct method of Ekman et al (1949), and nitrogenfree extract content was calculated from the figure of urinary organic matter which obtained by use of the Katayama\u27s factor 3.26 (1918). In three trials, there were no differences between the methods in their digestibility of crude protein, crude fat (ether extract) and nitrogen-free extract. However, the digestibility of crude fiber was higher in figure determined using the artificial anus technique than that obtained by the chemical method. In regard to the digestibility of crude fiber, figure which was obtained from the normal fowl with intact anus should be considered as a normal value. Besides the above facts, from a consideration of the chemical method are relatively simple in procedure and are available at any time regardless of age or sex, it seems reasonable to assume that this method has a value for practical usage