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筆者らは, 最近とくに減少しつつある作物の遺伝子源を保存し, その特性を再検討するという見地より, 各種の特用作物について, 在来系統の分布とその類縁性の解析, ならびに系統発生的分化に関する研究を実施中である。本法は, そのうち, 各地域より収集したシソの在来系統に対して主成分分析法を適用し, 系統の群別化と系統群相互の類縁関係を検討し, あわせて主成分のもつ生物学的意義について考察したものである。わが国および韓国より収集した39の在来系統に対し, シソ全体, 青シソおよび赤シソに区分した場合, 各々に対する主成分分析の国有値(λ_k)は, 第3成分までで全分散のそれぞれ74.4%, 84.8%および76.7%が表わされる。従って第3成分までの成分スコアによって系統の分類を行なった結果, シソ全体では10群, 青シソは11群, 赤シソは6群に分類される。この分類結果は, 本法と同様に距離に判定基準をおく場合のクラスター分析の結果とよく一致しているので, 主成分分析法はシソの系統分類の手法としてかなり有効であるものと推察される。青シソ, 赤シソとも, 同一群に所属する系統はシソ全体においてもほぼ同じ群に分類され, 質的形質である葉色発現機構の差異は, 量的形質に基づく分類結果に対して殆んど影響を及ぼさないものと考えられる。各主成分に関する生物学的意義を検討した結果, 一般にシソの特性決定には, 早晩性, 葉のちりめん状態, 粒重および分枝穂の形状が大きい支配力を有するものと推察される。, The 39 local lines of "Shiso" (Perilla frutescens Britton var. crispa Decne.) collected from Japan (38 lines) and R. O. K. (1 line) were classified by application of the principal component analysis (P. C. A.) in order to investigate the phylogenetic differenciation and to conserve desirable gene sources of the crop. Twenty nine characters were investigated, from which the representative characters were selected based on correlation matrix of characters showing significant line differences, and only these characters were analysed thereafter. Lines were divided by leaf colour to 29 green lines (Aoshiso) and 10 red lines (Akashiso). "Shiso" (Aoshiso+Akashiso), Aoshiso and Akashiso were analysed by P. C. A. separately, and the cumulative contributions of eigen values to the first three pricipal components amounted to 74.4%, 84.8% and 76.7%, respectively. Classification of lines by use of component scores of the first three components, as more than 70% cumulative contribution is enough to analyse, resulted in 10,11 and 6 groups in "Shiso", Aoshiso and Akashiso, respectively. The P. C. A. was considered an efficient procedure to classify the crop, because of coincidence of this classification result with the cluster analysis based on mean distances among characters. The lines belonging to the same groups in Aoshiso and Akashiso classifications were almost always assorted to the same groups in "Shiso" classification. Therefore, the difference in leaf colour manifestation as a qualitative character was considered unrelated to classification due to quantitative characters. Judging from the contributions of eigen vectors to the first three components, each component was interpreted to possess the biologlogical significance as follows : 1) First component : concerned with growing period, seed ripening and leaf shape. 2) Second component : concerned with growing period and luxuriance of plant. 3) Third component : concerned with shape of maximum branch. From the result mentioned above, the P. C. A. is contemplated to give promissing clues to the concideration of phylogenetic differenciation and to search and selection of breeding materials in "Shiso".

ハトムギ, ジュズダマおよびその雑種F_1ならびに4xF_1の4植物の耐水性の差異を検討するために湛水試験を行なつた。草丈は各植物とも湛水1週間後に生育抑制があらわれるが, ジュズダマ, F_1および4xF_1の3植物は, 生育後期に急速に回復し, 伸長停止期には標準区に比べかなりすぐれた。また分蘗数および葉数の増加に対する湛水の影響も植物種類により差異がみられ, ジュズダマは湛水により生育促進の傾向を示し, F_1もほぼこれに近く, 4xF_1では分蘗数に対する抑制が認められた。これに反しハトムギは両形質とも湛水の初期より著しく生育抑制がみられ, 生育後期ほどその影響は顯著であつた。成熟期における茎葉諸形質の測定の結果, 草丈, 分蘗数, 葉数および葉長などの形質は, 葉巾, 葉厚および稈径などに比べ, 植物の耐水性の差によつて湛水による増減が著しい。各植物とも花粉稔性には湛水による差異はみられないが, 種子稔性は湛水によりやや向上した。湛水により根長の発育は著しく抑制されたが, 多数の細根の発生によつて根重は各植物とも増加した。本実験の結果より耐水性に関しては, ジュズダマおよびF_1は極めて強く, 4xF_1はこれらに次ぎ, ハトムギは最も弱いことが判明した。, The present paper deals with the results of investigations on the submersion resistance of four Coix varieties, namely Hatomugi (Coix Mayuen ROMAN.), Juzudama (C. Lacryma-Jobi L.), F_1 (Hatomugi×Juzudama) and 4xF_1 plants. These Coix plants were planted in wagner's pot and submerged. Throughtout these four Coix varieties, the growth of plant height, number of tillering and number of leaves were inhibited in about 1 week after submersion. But the recuperation of these growth in Juzudama and F_1 and of plant height in 4xF_1 were recognized remarkably in 5∿7 weeks after submersion. In the date of maturity, these characters of Juzudama, F_1,and 4xF_1 planted in submerged plot were superior than the control. The seed fertility and dry matter of roots in the submerged plants were increased. From these results mentioned above, it will be identified that the submersion resistance of Juzudama, F_1 and 4xF_1 are superior than Hatomugi.

わが国各地に分布するCoix属植物は, 栽培種のハトムギと, 野生種のジュズダマの2種を主体とし, オニジュズダマの分布は少ない。したがって, ハトムギおよびジュズダマのわが国における生態型を把握するために, 地理的分布にともなう主要形質の変異について考察した。すなわち, 全国各地から収集したハトムギ16系統と, ジュズダマ28系統を1961年に栽植し, 草丈, 分けつ数, 出穂期, 花粉稔性および種子稔性などの諸形質を調査した。その結果は次のとおりである。1)主要形質の系統平均値は, 緯度によってかなり変動しているが, その分散は, 各形質とも野生種のジュズダマの方が大きく, とくに草丈の変異程度はハトムギの4倍に近い。2)諸形質の系統平均値は, 概して緯度との間に負の相関および回帰が存在し, 北方系統ほど矮小な早生型が分布しているが, この傾向は野生種のジュズダマにおいて著しく, 緯度にともなう系統平均値の変動も大きい。3)諸形質の系統内変異については, 両種とも概して北方系統ほど, 草丈, 分けつ数などの茎葉形質の変異が小さく, 形質の安定化が認められる。4)花粉稔性は, 高緯度になるにつれて低稔性個体が出現し, 系統内変異も大きい。5)栽培種のハトムギは, 野生種のジュズダマに比べて, 諸形質の地理的変異も, 系統内の個体変異もともに小さく, 比較的安定した種と考えられる。, The origin of genus Coix can be traced to India and South-East Asia. Two main kinds of genus Coix in Japan are Hatomugi (Coix Ma-yuen ROMAN., C. Lacryma-Jobi L. var. Ma-yuen STAPF. etc.) and Juzudama (Coix Lacryma-Jobi L.). It is not clear when Juzudama came over to Japan but it was known pretty early as wild plant, but it is clear from documentary souces that Hatomugi is a comparatively new plant, which came over from China at the biginning of the nineteenth century. Nowadays, these species are distributed throughout Japan as drug and fodder crop (Hatomugi) or wild plant (Juzudama). To investigate geographically the morphological variation in Hatomugi and Juzudama, the present writer had collected many strains of these specics from all part of Japan. The variance of mean of plant height is greater in Juzudama than in Hatomugi and the range of variation is from 72cm to 181cm in Juzudama while in Hatomugi it is from 115cm to 148cm. The plant height of Juzudama is lower at high latitude than at low one, but in Hatomugi this tendency is not manifest. The correlation and regression coefficient between strain mean of plant height and latitude is -0.742^ and -14.541^ in Juzudama and -0.336 and -1.324 in Hatomugi. The mean of number of tillers is greater in Juzudama than in Hatomugi but the correlation and regression coefficient between strain mean and latitude is negative in both species. And in lower latitude Hatomugi heads earlier while at high latitude there are some strains of Juzudama which heads earlier than Hatomugi. The correlation coefficient in this case is about -0.7 and heading becomes earlier by six days with rise of latitude by one degree. Early maturing type of Hatomugi is seen at high latitude but its correlation is not significant. The variation of character within a strain is estimated by means of coefficient of variation. With regard to plant height, number of tillers and heading date in Juzudama, the coefficient becomes less with the rise of latitude and especially in plant height is shown highly significant negative correlation with latitude. From this result it is manifest that the difference of geogrophical or ecological type between wild species and cultivated ones of Coix in Japan is brought about by the difference of date of introduction and method of availing.

ハトムギとジュズダマの正交雑のF_3より, 草丈に関して任意に43個体を抽出し, また, 240cm以上の高稈個体より正交雑について8個体, 逆交雑について7個体をそれぞれ選抜してF_3系統を培養し, 諸形質間の関連性および遺伝力について検討を行なった。1.任意抽出によるF_3の草丈の系統内分散は大きく, F_2のヘテロ性の高いことが推察されるが, 高稈系統ほど系統内変異の程度は概して小さい。2.草丈と諸形質間の遺伝相関は, 表現型相関よりも高く, とくに出穗期との間にはきわめて高い正の遺伝相関が, 分けつ数との間には負の高い遺伝相関がそれぞれ認められる。しかし, 種子稔性との間には相関は認められない。3.諸形質の系統平均値の親子相関による遺伝力は, 草丈で+0.853,出穗期で+0.801ときわめて高く, 分けつ数にも+0.494の有意相関が認められる。花粉稔性および種子稔性は, F_2の低稔性個体の稔性が著しく向上するために, 親子相関はきわめて低く現われるものと考えられる。回帰による遺伝力は, 概して相関による場合よりも低く, 分散分析による場合は, 相関とほぼ同程度である。以上の結果は, 本雑種の多収性の高稈系統が, いずれも晩生系統であることを示すものである。4. F_2の高稈個体の選抜によって培養したF_3系統においては, 親子相関および回帰による諸形質の遺伝力は概して低いが, 出穗期には比較的高い正の相関と回帰が認められる。また, 草丈と出穗期との間には, 任意抽出系統群におけると同様に正の有意相関が認められる。5.草丈の遺伝獲得量より推定した遺伝力は概して低く, 正・逆交雑ともほぼ0.4程度を示すにすぎない。このことは, 本雑種における初期世代の選抜効果が低いことを意味する。6.以上の結果より, 本雑種後代に, 系統内の草丈分散が小さく, 高稈性でかつ栄養生長期間の長い晩生系統を育成する可能性はきわめて高いと考えられる。, The present paper deals with the investigation on the variation and heritability of some morphological characters of F_3 strains between Hatomugi (Coix Ma-yuen Roman.) and Juzudama (Coix Lacryma-Jobi L.). F_3 strain was bred out of 43 F_2 individuals of random sampling and 15 selected tall plants. The mean of plant height of F_3 strain were distributed uninterruptedly over between 110cm and 250cm. The coefficient of variation of plant becomes less in tall strain and the correlation coefficient was at -0.823. The phenotypic and genetic correlation between plant height and some other characters were calculated by means of analysis of variance and analysis of covariance. As a results, plant height was proved to have a negative correlation with number of tillers but a high positive one with heading date. Heritability of character was estimated by means of correlation and regression between F_2 individual and F_3 strain and more over analysis of variance, and heritability appeared comparatively high through estimation by means of correlation. Heritability estimated by means of correlation in plant height and in heading date was very high, marking more than 0.8,and in number of tillers it marked about 0.5. But as for pollen and seed fertility, heritability can scarcely be recognized because of recovery of fertility in F_2 individual which is of poor fertility. In F_3 strain bred out of selected tall F_2 individual, positive correlation (0.5) and regression (0.5) between F_2 individual and F_3 strain were recognized in heading date, but in other characters the correlation and regression were not remarkable and selection of early generation is not effective. Thus, it can be expected that we can breed up a tall, lately maturing strain of high yielding ability out of later generations of this hybrid.

1,Zea属とCoix属との属間交雜に於ては, Zea×Coixの交雜は不成功であるが, Coix×Zeaの交雜は成功する。本研究の結果によれば雑種々子獲得率は6.2%であつた。2,これら属間交雑のCrossabilityは全くその柱頭上に於ける花粉の発芽能力によるものと思われるが, その理由は未だ明かではない。3,本実験の結果獲得された雑種々子は少量の為, その稔性は未だ検定せられて居ない。4,今後引続き花粉の発芽, 花粉管の伸長と授精現象及その胚の発育状態と交雑成功歩合との関係を明かにし, 併せて雑種々子の稔性及びその子孫に於ける細胞遺伝学的研究, 並びにこれら両親作物の複二倍体の育成等, 本来の育種学的研究へ展開せしめなければならない。, 1. In the intergeneric hybridization between the genus Zea and Coix, the combination of Zea×Coix was unsuccessful, but the reciprocal combination Coix × Zea was successful and some F_1 hybrid seeds were obtained in this experiment and the successful percentage was about 6.2%. 2. In this intergeneric hybridization the crossability between the two genera will be probably due to the germinating ability of pollen on the stigma with each other, but the reason about this problem is not clear up to date. 3. The fertility of F_1 hybrid seeds, obtained in this experiment, is not tested now owing to the small quantity. 4. Hereafter we will clear the relations between the success of this intergeneric hybridization and the germinating ability of pollen on the mutual stigma, the growth of pollen tube, the fertilization between them, and the development of embryo; and will study the fertility of F_1 hybrids and the cytogenetical investigations about their progenies, and then will expand this study, for example, from the breeding angle to produce some amphidiploid crops.

1. 茶の人為的倍数体の育成について, その倍数化の可能性を実験する目的を以つて, 品種籔北を材料としてその幼芽を縱に切開して生長点を, 露出せしめて直接Colchicneを作用させる点である。処理濃度は0.2%とした。3. 倍数体の検定方法としては各個体の中央位にある葉の裏面の中央位をSUMP法により検鏡して気孔の大きさを測定し, 之を無処理のControlと比較した。染色体数による直接鑑定は未た行われて居ない。leaf smear methodを応用する研究は目下進行中である。4. 有望と思われる倍数体として4個体を得た。即成功歩合は19%であつた。従つて本研究の方法によつて茶の人為的倍数体の育成の可能性を認める事が出来た。, 1. This xperiment was caried out to induce the tetraploid tea plant, artificially by treating the young bud with colchicine solution. 2. The essential point of this experiment consists in exposing the shoot growing point of the young bud, so that the colchicine can reach easily and guickly. When the young bud reaches the length of 2∿3mm., it is split longitudinally from top to base with a safety razor blade. Into the base of the split is inserted a small cotton ball which then wetted with 0.2% colchicine solution. 3. The identification of polyploid plant was performed by measuring of the length of stomatas by SUMP method, on the middle part of back side of the leaf, which locates on the middle part of the shoot developed from the treated bud. 4. We identified apperently 4 tetraploidlike plants artificially in comparison with the control, then we considered we can artificially induce the polyploid tea plant by this method.

Coix属植物中の2種, ハトムギ(C.M.), ジュズダマ(C.L.)と, その雑種後代に育成した高桿系統F_4および倍数体の4xF_1の4種類の植物に対し刈取試験を行ない, 植物形態と生産力との関係について考察した。刈取は生育期間中に1∿4回実施したが, 各刈取区の最終刈はいずれも草丈の伸長停止期に行なつた。刈取後の再生枝の伸長速度には植物種類間にかなり明らかな差が認められ, 刈取頻度のいかんをとわずF_4は最も早く, かつ刈取を増すとともにF_4と他種の伸長差は大となる。4xF_1の草丈は, 初期の刈取ではC.L.より劣るが, 刈取頻度の増加とともに回復してC.L.をしのぐようになる。分蘗数はF_4が最も多く, 4xF_1は最も少ないが刈取頻度の増加にともない各作物とも急速に再生枝を分蘗し, 常に刈取前の分蘗をしのぐが, その状況はF_4とC.M.が特にすぐれ, C.M.および4xF_1との間に明らかな差異を示している。刈取直後の生体重は, 一般に各刈取区を通じてF_4が最も大である。4xF_1は1∿3回刈取区ではC.L.よりかなりすぐれるが, 後期の刈取区でやや劣つた。植物種類間および刈取頻度間には高い有意性を示した。以上の実験結果より, 供試植物中F_4は最も高い生産性を示し, 4xF_1,C.L.がこれにつぎはC.M.は最も劣ることが判明した。特にF_4は両親植物に比し, 各刈取区を通じて2倍以上の多収性を示した。一般に各植物とも年2回刈が最も多収であつた。他の刈取区では概して3回刈が良いが, 植物の種類により多少変異している。育成F_4系統に関しては2回刈が最も適当であり, 1回および3回刈もかなりすぐれている。4xF_1およびC.L.については2∿3回刈が適当であると思われる。, The present paper deals with the investigation on the relation between cutting numbers and grass yields of some Coix varieties. The Coix varieties used in this study are Hatomugi (Coix Ma-yuen ROMAN., C. Lacryma-Jobi L. var. Ma-yuen STAPF. etc.), Juzudama (Coix Lacryma-Jobi L.), a strain in F_4 generation (Hatomugi × Juzudama), and 4xF_1 plants induced by colchicine treatment. In early growing stages of Coix plant, there are no remarkable difference in the growth of plant height of these Coix varieties. The difference of growth of plant height was recognized distinctly after the beginning of August. In this experiment the cuttings carried out from one to four times in growing stage of above Coix varieties. After the cutting of different cutting stages, the growth of plant height of F_4 strain was the most superior to that of the other varieties. With increase of cutting frequency, the number of tillerings increased rapidly compared with tillering before cutting and this tendency showed through four varieties especially F_4 strain and Juzudama resuscitated more tillerings than Hatomugi and 4xF_1. The grass weight of F_4 strain in cutting stages had the advantage over the other varieties, except in the third cutting of three cuttings. On the total grass yield of all cutting stages, F_4 strain showed high productivity that is about twice yield compared with that of parents. Generally speaking, the more useful number of cutting are two or three times in the growing stage of Coix varieties. From these experimental results, it was concluded that the F_4 strain was the most useful for soiling crops, especially we would be expected the heighest grass yield in the two times of cuttings. 4xF_1 and Juzudama are also useful varieties for soiling crops, if the sutable cutting stage in two or three cuttings are selected.

Coix属植物の2種, ハトムギとジュズダマの正逆交雑F_2における主要形質の分離状態を調査し, 優良系統育成の可能性について検討した。出穂期は正逆交雑とも早晩2群に分離し, 早晩比は10 : 54で, 出穂期を支配する3遺伝子を仮定し, 1種類の場合早生群を, 2種類以上の遺伝子を共存する場合晩生群を出現すると考えることによつて一応説明された。茎葉諸形質の平均値はF_1に比し低下したが, 草丈, 分蘗数および生体重の平均は両親よりかなりすぐれていた。正交雑の花粉および種子稔性は逆交雑よりすぐれたが, その他の形質では交雑方向による差は認められなかつた。形質の変異係数は一般に正交雑が小であつた。草丈の頻度分布は, 両親およびF_1型の3部分にわかれた。広義の遺伝力は, 諸形質とも高い値を示した。諸形質間の表現型相関および遺伝相関は, 正逆交雑とも草丈と葉長, 生体重および出穂期との間, また葉長と葉巾の間にかなり高い正相関が認められ, 遺伝相関は常に表現型相関より高かつた。柱頭色はF_2の分離状態より, 補促的に作用するM, Lなる2遺伝子の存在が明らかにされた。また種皮色および硬度についても, 前者は不完全優性の, 後者は完全優性の1遺伝子によつて支配されることが明確にされた。種皮色および柱頭色と量的形質間の関連性は明らかでないが, 種皮色ではF_1色個体が草丈と葉長でまさり, 柱頭色では, 赤紫色個体は白色個体より草丈, 分蘗数および葉長でややまさり稔性では劣る傾向が認められた。ハトムギは1年性, ジュズダマとF_1は越年性であるが, F_2は約80%が越年した。越年個体の再生草丈は, 高稈個体がややすぐれ, また晩生のジュズダマ型およびF_1型の越年能力は, 早生および矮生のハトムギ型個体に比べ著しくすぐれていた。本実験の結果より, ハトムギとジュズダマの雑種後代において, 茎葉生産量の高い越年性の晩生高稈系統を育成することの可能性の高いことが明らかにされた。, The present paper deals with the investigation on the genic segregation in the F_2 generation between Hatomugi (Coix Ma-yuen ROMAN.) and Juzudama (C. Lacryma-Jobi L.). On the heading date, all F_2 plants were segregated in two groups of early and late maturity. The ratio of early and late maturity in the F_2 plants was 52 to 285. So the author presume that the maturity is determined by 3 gene and the late maturity is owing to the 2 or 3 dominant genes. Generally the variations of chracters in F_2 plants were larger than both parents and F_1 plant, but the mean values of plant height, number of tillering and plant weight of F_2 plants were heigher than parents. In the main characters except pollen and seed fertility, there are no significant difference between two combinations of crossing. In the crossing of Hatomugi×Juzudama the coefficients of variation of many characters were lower than reciprocal crossing. Phenotypical and genetic correlation were calculated chiefly between plant height and the other characters. In this result, high correlation was recognized between plant height and leaf length, plant weight, pollen fertility and heading date and between leaf lengtn and leaf width, as positive respectively, but to the number of tillering as negative. The vigorous type for plant height was not recognized in all plants belong early maturity group. The inheritance of qualitative character in this crossing was observed to the stigma colour and seed characters. The stigma colour shows clear red-violet in F_1 plants though both parents have white stigma. The colour of seed coat of Hatomugi, Juzudama and F_1 are brown, white spot on black ground and brown and green stripes respectively, and solidity of seed coat are soft, hard and hard respectively. From results of segregation in F_2 plants the author determined on the genotypes of stigma colour and seed characters as follows. Hatomugi…MMll, jj. Juzudama…mmLL, JJ. (M and L are complemantary factors for stigma colour and J is complete dominance for solidity of seed coat and incomplete dominance for colour of seed coat.) The linkage between some quantitative characters and seed coat colour or stigma colour shows no remarkable tendency, but F_2 plants which have F_1 colour in seed coat were superior than the others for plant height and leaf length. In the stigma colour, the plants which have redviolet were superior than the plants which have white stigma for plant height, number of tillering and leaf length, but inferior for pollen and seed fertility. In our country, Hatomugi is annual plant but Juzudama and its F_1 plant are hibernant plant. The hibernation ability of the F_2 plants belong early maturity group and dwarf type was inferior to the plants of late maturity and Juzudama or F_1 types. From these experimental results, for the improvement of genus Coix, it will be most significant to breed the lines of vigorous types for plant height in the progeny of interspecific hybridization between Hatomugi and Juzudama.

In orchard grass, Dactylis glomerata L., some experiments on the bulk emasculation by hot water method wese made. 7 temperature classes (41°-53℃) and ll time classes (1-40minutes) were used in combinations. In view of the destruction of the function of pollen, the percentage of the setling and germination of seeds, the treatments 43℃-15minutes and 41℃-30minutes were found best for practical use. 41℃-40minutes and 45℃-7minutes may also be useful.

Coix属植物の栽培種であるハトムギと野生種のジュズダマ, およびその雑種F_1さらに人為的に作出した4xハトムギと4xF_1の5植物の乾燥種子に対して5∿20krのX線を照射し, 照射当代におけるX線感受性と, さらに照射F_1の次代における形質の分離および形質間の連関性に対するX線の作用を調査した。1.照射当代の発芽率および生存率は, 照射線量の増加にともない低下するが, 概してF_1は抵抗性を示し, 異質および同質四倍体はこれにつぎ, ハトムギおよびジュズダマは供試植物中最も感受性を示した。出穂期は, 両四倍体は線量増加にともないかなり遅延し, ハトムギおよびジュズダマはやや出穂促進の傾向を示したがF_1は殆ど影響されない。草丈は一般に線量とともに低下するが, F_1は5∿15krの線量では殆ど影響されない。花粉稔性はF_1および4xF_1では15krまでは殆ど低下せず, 20krにおいてかなり低下した。他の3種は線量増加にともない減少したが, 同質四倍体は花粉稔性については感受性が大である。種子稔性は線量とともに一次函数的に低下したが, F_1および四倍体は, ハトムギ, ジュズダマに比してその傾向は著しくない。2. F_1 (X_1)個体中の極早生個体によりF_2を育成したが, 早生選抜の効果はなく, 概して晩生個体を多く分離した。草丈の頻度分布はやや連続的となり, 線量とともに細茎を叢生する矮生個体がかなり出現した。生体重は高線量区でかなり増大する傾向を示した。花粉および種子稔性はいずれも低下し, とくに高線量区には低稔性個体の出現が多い。草丈と諸形質間の相関は, 対照区に比較してかなり低く, とくに分蘗数, 生体重および稔性などと草丈との間において著しく, 概してX線照射は遺伝子の多面発現ないしは連鎖に大きく影響することが推察された。3.本実験結果より, 雑種F_1はX線に対して最も抵抗性を示し, 異質および同質四倍体はこれにつぎ, ハトムギおよびジュズダマは最も感受性を示すことが明らかになつた。またX線照射を利用して雑種後代の育成を行なう場合には, 変異個体の選抜はもとより, とくに有用形質間の連関性を把握しつつ行なうことが必要であると考える。, The present paper deals with the investigation on the radiosensitivity of several Coix varieties in the X_1 generation and the genic segregation in the F_2 generation raised from irradiated F_1 seeds. The Coix varieties used in this experiments were Hatomugi (Coix Ma-yuen ROMAN.), that is cultivated type in genus Coix, and Juzudama (Coix Lacryma-Jobi L.), that is wild type, and its F_1 hybrid, and two tetraploid varieties, namely autotetraploid Hatomugi and allotetraploid between Hatomugi and Juzudama. Dry dormant seeds of these varieties were irradiated with X-rays of 5-20kr. After treatments, these irradiated seeds were sown in the seed bed together with control respectively. Germination and survival rates decreased linearly according to the dosage. But the radiosensitivity on the germinating and survival ability of F_1 hybrid were lowest in all varieties and auto-and allotetraploids came after F_1 hybrid. Heading date of Hatomugi and Juzudama were early with the increase of dosage, in spite of two tetraploid were delayed. The plant height in each maturity of treated varieties inhibited with the higher doses of X-rays. The pollen fertility of the irradiated F_1 and 4xF_1 varieties showed no decline as compared with the control except the decrease of fertility in 20kr, but in the other varieties decreased linearly with the increase of dosage. As for the pollen and seed fertility of F_1 and 4xF_1 showed higher resistance than the other varieties. The earliest plants on heading date in irradiated F_1 plants were selected to grow F_2 progenies. In the F_2 (X_2) generation, the effect of selection on early heading in F_1 (X_1) plants was not recognized and the rate of late heading plants at higher doses of X-rays was much higher than in the control F_2 generation. The frequency distribution on plant height of F_2 (X_2) progenies showed continuous deviation whereas three types were segregated in the control F_2. In the F_2 (X_2) generation, the dwarf plants with many slender tillerings and the vigorous plants on the plant weight were observed at the heigher doses. As for the pollen fertility, the frequency of partially and completely sterile plants increased with dose rates. Asimilar tendency was observed in seed fertility. The phenotypical correlation were calculated chiefly between plant height and the other characters. In this result, correlation coefficients in X-irradiated F_2 were inferior to control F_2,especially low correlation was recognized between plant height and some characters namely number of tillering, plant weight, pollen and seed fertility as compared with the correlation between same characters in control F_2 plants. From these experimental results, it was concluded that the F_1 (Hatomugi×Juzudama) plants were the most resistant to radiation and auto- or allotetraploid Coix are resistant for only 2 or 3 characters and Hatomugi and Juzudama, that is the diploid species of Coix, had high sensitivity for many characters, on the other hand, it was conjectured from segregation of characters of F_2 plants to result from X-irradiated F_1 plants that the function of X-ray dose to character manifestation have effect sensitively upon the linkage or pleiotropism of genes.

1. 温湯法による集団除精法を種々の作物に適用する際に, 供試花の成熟程度によつて花粉の熱に対する抵抗力に差がある様に思われる。此の点を明らかにする為に, 水稲品種「千本旭」を用いて幼穂並に花粉の成熟過程の観察と, その種々なる時期に於ける温湯処理が, 花粉及び雌蕊の機能に対し如何なる影響を及ぼすかを調査した。2. 処理条件は, 低温区40℃-8分, 標準区43℃-8分, 高温区46℃-8分の3区とし, 処理時期を, 通常処理期, 出穂期, 出穂前3∿5日, 7∿8日, 11∿13日の5期とし, 両者を組合せて15試験区を設けた。3. 出穂期以前の処理により, 供試穂の出穂期に変動を来さしめなかつたので, 出穂前日数の決定は, 処理がその穂の出穂期に先立つ日数を以つてした。4. 花粉の成熟状態は, 出穂前11∿13日では花粉母細胞のMeiosis, 7∿9日では花粉の外殻形成期, 3∿5日は花粉内容の充実期であり, 出穂期以降に於いては花粉粒はすべて完成していた。5. 温湯処理後直ちに袋掛けを行い, 自家結実の状態によつて花粉の機能を調査し, 一方Clipping methodによる結実率によつて雌蕊の機能を調査した。更に結実種子の発芽試験を行い, 之等に対する処理の影響を考察した。6. 花粉の熱に対する抵抗力は, 成熟過程にあるものは一般に強く, 出穂期に於いて著しく弱まり, 開花直前の成熟花粉が最も弱かつた。又出穂期以降に於ける雌蕊の熱に対する抵抗力は, 花粉のそれに比して著しく強いものと思われる。7. 結実種子の発芽は, 最適処理条件区のものが最も良好であつたが, 処理, 時期による差は認められなかつた。8. 以上の結果より, 温湯法により集団除精を行うに際しては, 処理に先つて開花直前の成熟程度均一なる頴花を選び, 未熟花はつとめて摘除する必要のあることが判明した。, 1. The present paper deals with the results of investigations on the observation of growing stages of immature panicle and pollen grain of rice variety "SENBON-ASAHI" and on the effect of hot water treatments in several times of these stages upon the function of pollen and ovule. 2. In this tests, 3 conditions of hot water treatment were adopted, that is low (40℃ for 8 minutes), standard (43℃ for 8 minutes) and high (46℃ for 8 minutes) temperatere section. These treatments were carried out on 5 different stages namely optimum time of treatment, heading date, 3 to 5 days before heading, 7 to 9 days before heading and 11 to 13 days before heading. 3. Heading date of treated panicle was unchanged owing to the treatment before heading, for this reason "days before heading" was determined by the number of days preceding the heading date of treated panicle. 4. The aspect of growing pollen was observed as follows : Meiosis of pollen mother cell was found in 11 to 13 days before heading, outer hull of pollen was formed in 7 to 9 days before heading, protoprasm of pollen was incresing in 3 to 5 days before heading and all pollen grains were complete after heading date. 5. Pollen function was tested by the fertility of treated panicles pollinated with treated pollen and ovule function was by the fertility of treated panicles pollinated with normal pollen by clipping method. 6. About the heat resistance of pollen, pollen in growing stages was generally stronger than complete pollen and especially the pollen just before the flowering was most inferor. It was considered that heat resistance of ovule was very strong as compared with the pollen after heading. 7. The germination of seeds which raised under the optimum time of treatment were best of all, but no evident tendency due to different conditions and stages of treatment was recognized in germination of seed. 8. According to these results, it was identified that we must select uniform florets on degree of maturity and must remove immature florets in treated panicle as much as possible.

1.ハトムギとジュズダマの雑種F_3系統群中より, 高稈で草丈の系統内変異の小さい系統を選抜してF_4系統を, さらにF_4世代より高稈系統を選抜してF_5系統をそれぞれ培養し, 草丈に関する選抜効果について検討を行なった。(i) F_4世代の草丈の系統内変異は概して小さく, 草丈が著しく分離する系統はF_3に比べて少ない。また, 高稈系統ほど草丈の変動係数は小さい。F_5世代においては, さらに分離系統は少なく, 草丈の変動係数も減少し, ほとんどすべての系統はハトムギおよびジュズダマの系統内変異よりも小さい。また, F_5世代の系統間分散はF_4世代に比べて減少し, 全系統平均値の両親植物に対する増加割合はF_4世代よりも大きい。(ii) F_4世代における草丈と主要形質間の相関では, とくに出穂期との間に正の有意相関が認められ, 遺伝相関も表現型相関とほぼひとしい。また, F_3世代までに認められた草丈と分けつ数との間の負の有意相関は認められない。草丈と花粉稔性および種子稔性との間にはそれぞれ正の相関が存在する。F_5世代においても, 草丈と出穂期との間には高い有意相関が認められ, 両形質の遺伝的関連性は強いが, 他の形質との間には有意相関は存在しない。(iii) F_4世代の親子相関および回帰による諸形質の遺伝力は, いずれも有意の値を示し, とくに出穂期は相関および回帰ともきわめて高い。この傾向は, F_4の系統にもまた系統群についてもほぼ同様であり, F_3の高稈選抜によっても諸形質の遺伝力はかなり高いと考えられる。F_5世代の諸形質の遺伝力は, 出穂期にのみ有意性が認められ, 本世代においても出穂期の遺伝力は大きい。他の形質にはいずれも有意性はなく, とくに草丈の遺伝力はかなり低い。すなわち, F_5世代における高稈性の選抜効果はF_2∿F_4世代ほど大きくなく, 草丈の固定度はかなり進んでいると考えられる。(iv)以上の結果, F_5系統中に230cm以上の高稈性で系統内分散が小さく, 栄養生長期間の長い晩生系統で, ハトムギ程度の分けつ数を有し, かつ, 90%以上の高稔性を有する系統を多数獲得することができたが, これらの育成系統は飼料作物としての利用はもちろん, 今後の研究素材としてもかなりすぐれたものと思考される。2.育成系統の種子発芽力はきわめて高く, 発芽率は雑種世代の進むにつれて向上し, F_6種子においては, 90%以上の発芽率を示す系統数は, 全系統の84%をしめている。この結果より, 育成系統の種子繁殖はきわめて容易であると考えられる。, From the results of statistic analysis of some morphological characters in F_3 generation between Hatomugi (Coix Ma-yuen Roman.) and Juzudama (Coix Lacrma-Jobi L.) (Murakami et al., 1964), it can be expected that we can breed up a tall, lately maturing strain of high yielding ability as fodder crops. The present paper deals with the selection effect on tall culm strains of F_4 and F_5 generations. 51 strains of F_4 were bred out of selection of tall F_3 strain and tall individual, and selection effect on characters was examined mainly with regard to plant height. Generally speaking plant height variance in F_4 strain was less than in F_3 and emergence of strain with tendency to plant height segregation was also few. Phenotypic and genetic correlation between plant height and heading date was high and significant. Significantly negative correlation between plant height and number of tillers recognized in former generation was not recognized in F_4. Heritability was estimated by means of correlation and regression between F_3 and F_4,and significantly positive correlation was recognized in many characters, especially in heading date. In F_3 family selected according to tallness, relationship between tallness and lateness of maturity was remarkable and heritability was estimated to be high. Among F_4 strains appeared many useful strains tall and of less segregation of plant height. Out of F_4 strain F_5 was bred up by means of more rigorous selection as to the tallness of plant. Though it depended on natural pollination within F_4 strain, there was scarcely influence of heterozygosis and the variance of plant heigh in the strain was little. When we compared the increase in mean plant height of whole strains of F_4 and F_5,taking parent plant of each as basis of comparision, it was greater in F_5 than in F_4. In this generation too, high correlation of 0.67 was still recognized between plant height and heading date but among other characters no correlation was recognized. Heritability of heading date was significant but it was not so in other characters. Germinating ability of seed became higher with the advance of generation up to more than 80%. And it was proved that the strain with tall height and high yielding ability is available by means of seed propagation.

In Timothy, Phleum pratense L., some experiments on the bulk emasculation by hot water method were made. 7 temperature classes (41'53'C) and 10 time classes (2-40 minutes) were used in combinations. In view of the destruction of the function of pollen as well as the higher percentage of seed set, the treatments 43'C-15 or 20 minutes and by 45 ?? -10 or 15 minutes were found best for practical use. 41'C-30 or 40 minutes may also be useful. The germination of seeds thus obtained was good, no remarkable difference being observed among different conrbinations in treatments.

1. sudan grass及びmeadow foxtailについて温湯除精法の処理条件を実験した。2. 処理温度はsudan grassは41℃∿53℃迄を2℃間隔に7区, meadow foxtailは39℃∿49℃迄を2℃間隔に6区とり, 処理時間は共に1分, 2分, 3分, 5分, 7分, 9分, 12分, 15分, 20分, 25分, 30分とし, 両者を組合せて試験区を設けた。3. 処理後各区に於いて, 花粉の発芽力, 雌蕊の受精力, 結実種子の発芽率及び植物体の諸部に対する処理の影響を調査した。完全除精区に於ける結実率の高いものを実用に適する処理条件と決定した。4. 本実験の結果, 実用に適する処理条件はsudan grassでは45℃-12分であり, meadow foxtailでは43℃-5分である。, In sudan grass, Sorghum sudanense STAPF. and meadow foxtail, Alopecurus pratensis L. some experiments on the bulk emasculaton by hot water method were made. 7 temperature classes (41℃-53℃) for sudan grass, 6 temperature classes (39℃-49℃) for meadow foxtail and 11 time classes (1-30 minutes) for both crops were used in combinations. In view of the destruction of the function of pollen and the percentage of the setting of seeds, the treatments 45℃-12 minutes for sudan grass and 43℃-15 minutes for meadow foxtail were found best for practical use.

Coix属植物の飼料作物化試験に対する育種素材として, タイ国より野生系統を導入し, 本邦産Coixのハトムギ, ジュズダマおよびその雑種F_6系統との間に交雑を行ない, F_1雑種の形態と細胞遺伝学的所見より, 育種の可能性ならびに本邦産Coixとの類縁性について考察した。導入Coix 16系統はいずれもCoix Lacryma-Jobi L. (2n=20)に属し, 4変種群にわけられる。2系統を除いて出穂は認められないが, F_1雑種は9系統中7系統が出穂し, 3系統が結実した。F_1雑種の生育は概して旺盛で, 草丈, 分けつ数などの主要形質にヘテロシスを現わす系統も多く本邦産Coixの早生遺伝子の導入によって, 本雑種の利用性ならびに後代育成の可能性は高い。F_1雑種の花粉母細胞における染色体対合は, 10 IIがもっとも多く, 1価の出現頻度は交雑組合わせによりかなり差異が認められるが, 本邦産Coixの染色体との相同性は概して高く, 両者の近縁性もかなり高いと考えられる。, The present paper deals with the investigation on the morphological characters and cytogenetical observation of F_1 hybrid between Thailand and Japanese Coix varieties. Sixteen varieties of genus Coix introduced from Thailand belong to Coix Lacryma-Jobi L. with twenty somatic chromosome number. According to the specific classification of genus Coix based on the shape of seed, these varieties are classified into four varieties, that is var. major, var. monilifer, var. typica and var. stenocarpa. Thailand varieties except two varieties were not recognized heading. The crossing was attempted between eight varietes of Thailand Coix recognized heading after short day treatment and Hatomugi (Coix Ma-yuen Roman.), Juzudama (C. Lacryma-Jobi L.) and its F_6 strain showed vigorous type in some morphological characters. F_1 hybrids in these crossing were obtained in nine among eleven cross combinations. In the early stage of development, the plant height of F_1 hybrid shows a tendency to vigorous like Thailand Coix varieties and F_7 strains, but F_1 hybrid showed heterosis in plant height in date of maturity. Heading of F_1 hybrid was recognized in seven cross combinations and setting seed was obtained in three combinations among them. This suggests that the gene for early maturity of Japanese Coix varieties was introduced to Thailand Coix varieties. In some F_1 hybrids, number of tillers and number of leaves were vigorous as compared with both parent plants. Generally the coefficient of variation of plant height of Thailand Coix varieties were larger than Japanese Coix varieties, and that of F_1 hybrid was distributed between them. From this result, it can readily be imagined that the Thailand Coix varieties were heterogenious condition for genes which determine the plant height. With a view to investigate of affinity between Thailand and Japanese Coix varieties, the authors have observed chromosome configurations and their frequencies in meiosis of PMC's of F_1 hybrid. The chromosome association in meiosis of Hatomugi and Juzudama was shown 10II in all divided cells, and their forms were closed bivalent, but in the F_7 strains and a few Thailand varieties 9II+2I was observed in about 10% cells. The chromosome configurations in the F_1 hybrids were observed five types with 0,2,4,6 and 8 univalent, but the most frequency of appearance was 10II among them. The frequency of univalent in divided cells are variable due to difference of cross combination. As to this phenomena, it would be recognized that there are difference of homology of chromosomes and variation of karyotypes between Coix varieties used in this experimant. From these morphological and cytogenetical investigation mentioned above, it will be concluded that the Thailand Coix varieties are very available as breeding materials for improvement of genus Coix.

Coix属の育成系統に対する直播適応性を検討した。1)直播区の種子発芽は, 室内播種に比べて発芽開始が約10日遅れるが, 90%以上の高い発芽率を示した。2)草丈の伸長速度は, 直播の時期にかかわらず密植区は生育初期に, 疎植区は生育中期以降に大である。移植区もほぼ同様の傾向を示すが, 移植時の生育障害により成熟期にはかなり直播より劣る。3)分けつ数の増加に対しては, 直播の疎植は密植に比べて分けつ期間が長く, 初期の分けつ増加量も大きい。移植区も疎植により分けつは増大するが, 移植時の分けつ停止の影響が大きい。4)乳熟期における草丈, 分けつ数, 生体重, 乾物重などは, 直播は移植に比し, 疎植は密植に比し大である。形質の変動量は概して直播が小さく, 移植ではとくに密植により変異が増大する。点播粒数については分けつ数, 生体重でやや多粒播種がすぐれる傾向を示す。5)草丈および分けつ数と個体生体重との間には, とくに密植区にそれぞれ正の有意相関が認められる。6)個体当たりの生体重は, 一般に直播, 疎植かつ多粒点播区がすぐれるが, 単位面積当たりの生草収量は, 直播の密植区が著しく大である。7)以上の結果Coix属育成系統の直播適応性はきわめて高く, とくに生育初期∿中期の青刈利用では, 密播かつ多粒点播が望ましいと考えられる。, The present paper deals with the investigation on the adaptability test in direct sowing culture of improved variety of genus Coix. In the experiment, the growing process were investigated by means of planting in different seeding time, planting density and number of sowing seed in direct sowing comparing with those in the transplanting and analysis of several characters were culculated statistically in milk-ripe stage. The experimental result can be summarized as follows : 1. The sowing seed showed high germination percentage as above 90%, but the biginning of germination was delayed about 10 days compard with sowing in the glass house. 2. At the earlier growing season, in direct sowing and transplanting plots plant height in the densely sown plots was higher than that in the sparsely sown plots, but vice versa after that time. At the date of maturity, the plant height in transplanting inferior to that in direct sowing. 3. At the earlier growing season, the number of tiller per individual plant in the sparsely sown plot of direct sowing showed an incresed over that in the densely plot. But in the transplanting above tendency was ricognized at later growing season. 4. The mean value and coefficient of variation of plant height, number of tiller, plant weight and dry matter weight were calculated in the milkripe stage. These statistical values in direct sowing plots were larger than those in transplanting plots. It may be laid down as a general rule that the variates between plant of those characters in direct sowing were smaller than those in transplanting, especially, in transplanting the variates in densely plot showed an increased over that in sparsely plot. 5. In the experimental conditions en bloc, the high correlation between plant height and plant weight was recognized in densely sown plot, in the same way between number of tiller and plant weight. 6. In the sparsely sown and three sowing seed plot of direct sowing, the plant weight per individual plant showed maximum value, but on the yield (plant weight) per unit area, that in the densely sown plot of direct sowing was superior to that in other experimental condition. From these investigation mentioned above, it will be concluded that the improved variety of genus Coix are very adaptable as forage crop in direct sowing culture.

Coix属植物は栽植条件の変化により, 形質の発現に変異を生ずることは, 従来より観察されているところである。したがって, ハトムギ, ジュズダマおよびF_5の育成優良系統に対して, 栽植距離を30cm, 60cmおよび90cmとして混植試験を行ない, 密度および混植による形質および収量の変異を追究した。1.生育期間中の草丈の伸長に関しては, 各供試植物とも密度効果が生育の比較的早い時期より現われ密植区ほど伸長速度が大きい。混植による競合は, ハトムギおよびジュズダマでは高稈個体による伸長促進が認められ, 密植区ほどその傾向は著しい。分けつ数の増加に対する密度効果は, 草丈に対するよりも顕著に現われ, 各供試植物とも生育の初期より密植区の分けつは抑制され, 疎植区の分けつ増加速度はきわめて大きい。また, 生育期間中に現われる混植の影響は, 供試植物の違いによって異なり, 一定の傾向を示さない。2.草丈, 分けつ数および乾物重の変異について分散分析を行なった結果, 両親植物の全形質とF_5系統の乾物重に, 密度区間に有意差が認められる。草丈は一般に密植とともに増大し, 分けつ数および乾物重は減少する。混植による競合生起の傾向は, 供試植物の違いとくに草丈の長短によって異なり, さらにこれは, 密度の大小によって著しく変化するため, 供試植物を通じて法則性を発見することはできないが, 概して両親植物の草丈は, 混植によって密植区で促進, 疎植区で抑制され, F_5系統はすべて混植によって抑制される傾向が認められる。分けつ数および乾物重においても, 各供試植物とも種々の変異が認められるが, 一定の傾向を示さない。概して両親植物は, 混植によって負, F_5系統は正の競合値を示す。3.各供試植物とも, 異なる密度区における草丈と, 個体の乾物重との間には負の相関が存在し, 分けつ数と乾物重との間には正の相関が認められるが, 密植区における個体数の増大によって, 単位面積当たりの総乾物収量は, 草丈の増大する密植区がすぐれ, 分けつ数の増加する疎植区がもっとも劣っている。4.以上の結果, 育成高稈系統の栽培にあたっては, かなり密植することによって, 生産性を向上させることができると考えられる。また, 異型個体と混植する場合には, 競合効果が植物の種類と栽植密度によって, かなり異なるので留意を要する。, The present paper deals with the investigation on the competitive effect of some morphological characters of the genus Coix due to the change in environmental condition of culture. To investigate the non-genetical variation of characters of plants belonging to the genus Coix, the present writer cultured Hatomugi (Coix Ma-yuen Roman.), Juzudama (Coix Lacryma-Jobi L.) and F_5 strains bred with view to tallness in mix planting with three kinds of distance between each plant (30,60 and 90cm) and considered the variation of characters due to these conditions. Generally plant height, number of tillers and dry matter weight vary very much with the density of planting. That is to say, plant height increases considerably with dense planting while number of tillers and dry matter weight decreases remarkably. The variation of these characters due to density of planting changes its aspect again with mix planting and difference of kind of mixed plant have influence on the effect. Meanwhile the effect of mix planting is not so great as the effect of density. Interspecific difference of characters can not be clearly recognized in mix planting field, but generally speaking, short culm species are liable to be influenced by tall species. Though dry matter weight decreases by dense planting, harvest becomes larger as number of cultured plant increases remarkably. So the most effective method to high yield is to increase number of plant by means of comparatively dense planting. But before settling this matter, we must analyze the change of chemical composition of feed due to the change of characters and determine the best method of cultivation to enrich the com ponent useful as fodder crop.

Examinations of living zoospores of Phytophthora capsici with the phase contrast microscope reveal a small spherical body on many of the flagella. Before the zoospores emerge from the sporangia, they have two flagella already. Immediately after the zoospores emerge from sporangia, they move about rapidly and no small spherical bodies are visible on the flagella. One of the flagella swings severely foreward and the other slowly afterward. Later, as the zoospores begin to swim more slowly, a small spherical body appears on the middle part of the flagella. The flagella suddenly fold in two at the point of the spherical body and take an appearance of earpick shape. The flagella seem to wither completely or remain earpick-like. The zoospores stop their movement and the flagella, now being only spherical bodies or earpick-like structures, become detached and float away. Some different ways on transformations of flagella were observed in these examinations.

1. Coix属植物の倍数性育種の価値を検討する目的で, 1956年以来ハトムギ及びハトムギ×ジュズダマのF_1種子に対して, 0.1%コルヒチン溶液の芽生処理によつて同質及び異質四倍体植物を育成した。コルヒチン処理は, 両種共1日処理区が変異個体の最大出現区であり, 4xハトムギで14.6%, 4xF_1で15.0%を示した。2. 4xハトムギは, ハトムギに比べ生育がおそく, 成熟期において矮生態を示した。之に反して4xF_1はハトムギ, ジュズダマのいづれよりも生育大で, 伸長の各時期においてまさつていた。3.外部形態を測定した結果, 4xハトムギはハトムギに比して, 葉長, 葉巾, 葉厚, 稈径, 気孔の大きさ, 種子重, 種子の巾, 厚さ及び水分含量等においてすぐれ, 草丈, 分蘗数, 葉数, 葉面積, 生体重, 種子長等において劣つていた。之に反し4xF_1では, 水分含量を除いた測定全形質が大きい値を示した方の親より更に増量し, 特に草丈, 葉長, 葉巾, 葉厚, 稈径, 生体重及び種子重には有意差を認めた。4.花粉稔性は, ハトムギ及びジュズダマは共に良好で95%以上の値を示したが, 4xハトムギは83%, 4xF_1は79%前後に低下した。5.種実稔性もハトムギ及びジュズダマは共に90%前後の良好な結実率を示したが, 4xハトムギでは約20%, 4xF_1では約50%に低下した。猶自家受精では二倍体は50%前後に低下したが, 四倍体では著しく悪く1∿5%であつた。6.二年間の種子発芽試験の結果, 特に四倍体種子に発芽率の上昇が認められ, 1959年では4xハトムギが80%, 4xF_1では94%の極めて良好な値を示した。7.本実験の結果, Coix属の人為倍数体の育種学的利用は, ハトムギとジュズダマの異質四倍体の場合にはかなりの期待をもちうるものと思われる。即ち今後種子生産の向上, 形質の固定化等の操作を継続することにより, 将来のCoix属育種の素材として価値あるものと考える。, 1. The present paper deals with the results of investigations on the induced tetraploid plant of genus Coix. The coleoptile treatment by 0.1% aqueous solution of colchicine was attempted to the Hatomugi (Coix Ma-Yuen ROMAN. 2n=20) seed and F_1 hybrid (Hatomugi×Juzudama : Coix Lacrma-Jobi L. 2n=20) seed. The plants with big stomata in all treated plants were induced easily in 1 day treatment. That is, the percentage showed 14.6% in 4x Hatomugi and 15.0% in 4x F_1 plant. 2. The progress of growth of 4x Hatomugi was later than Hatomugi and at the ripenning stage 4x Hatomugi showed the dwarf type in plant height and number of tillering. But the growth of 4xF_1 was more excellent than Hatomugi and Juzudama. 3. Some important characters of tetraploids and diploids were studied in the ripenning stage comparatively. 4x Hatomugi were superior to the Hatomugi in leaf length, leaf width, leaf thickness, culm diameter, stomata size, seed weight, seed width, seed thickness and water content. Especially, in leaf thickness, culm diameter and seed weight, the significant differences were recognized statistically. While the plant height, number of tillering, number of leaf, leaf area, plant weignt and seed length were inferior to 4x Hatomugi as compared with Hatomugi, and in plant height, the significant difference was recognized negatively. On the contraly in 4x F_1 plant, all characters except water content were vigorous as compared with the superior parent. Especially, in plant height, leaf length, leaf width, leaf thickness, culm diameter, plant weight and seed weight, the significant differences were recognized statistically. 4. The pollen fertility of 4x Hatomugi and 4x F_1 were 83.1% and 79.5% respectively, in comparision to 98.4% of Hatomugi and to 95.4% of Juzudama. 5. The seed fertility of each tetraploid variety was lower than each diploid species. That is to say, in the natural crossing of same variety the fertility showed 22.0% in 4x Hatomugi and 52.5% in 4x F_1,in spite of the fertility of Hatomugi and Juzudama were 94.6% and 89.2% respectively. The seed fertility, however, varied from 13.7% to 38.6% in the plants of 4x Hatomugi and from 39.6% to 61.5% in 4x F_1. In the case of selfing the seed fertility was lower than natural crossing in all cases. 6. According to the germination test in two years, the germinating percentage of both 4x seeds got better annually. On the germination test in 1959,the germinating percentage of 4x Hatomugi and 4x F_1 were 80.0% and 94.3% respectively, in comparision to 47.5% and 56.5% in 1958. Especially, germination of 4x F_1 seed in 1959 was not significant difference to the Hatomugi (95.0%) and Juzudama (95.7%). 7. From these results mentioned above, it will be identified that the utilization of the induced tetraploid of genus Coix is fairly significant, because the 4x F_1 plant is allotetraploid of Hatomugi and Juzudama were superior to both parent in many important characters as forage crop.

1. Coix属は分類学上Zea属の近縁種である。Coix属を改良してZea属に代る飼料作物を育成する目的をもつて, 1956年以来Coix属内の種間交雑を開始した。即ち, ハトムギにジユズダマの越年性, 耐湿性等を導入する為に交雑試験を行つた。交雑は正逆2方向について行つたが, 結実率は夫々43.08%, 50.30%であり, 両者の交雑は比較的容易である。又交雑の方向により結実率に有意の差は認められなかつた。2. 種子の発芽試験の結果, ハトムギは83.93%の発芽率を示して最も高く, ジユズダマは45.31%で最も悪かつた。F_1はいづれも両親の中間の値を示し, 正逆交雑により夫々68.81%, 57.14%を示したが, 両者の間に有意差はなかつた。交雑の成功度として, 結実率との相乗積を算出すれば, 夫々2.96及び2.87で, 略々同様の結果を示した。3. 本交雑に於けるF_1植物は, 諸種の形質に関して著しくヘテローシスを表わした。即ち, 草丈, 分葉数, 葉数の3形質は, 生育の初期より旺盛な生育を示し, 特に分葉数は生育のごく初期に, 草丈及び葉数はその後期に増加程度が著しかつた。諸種の形質を成熟期に測定した結果, 草丈, 分蘗数, 葉数, 葉巾, 葉面積, 稈径及び生体重等は大きい値を示した方の親よりも更に増量したが, 就中草丈, 分蘗数, 葉巾, 生体重には有意の差を認めた。出穂期は両親の中間に分布し8月5∿10日であつた。刈取後の再生力は, 草丈, 分蘗数共に両親より強い傾向を示した。猶正逆交雑による2つのF_1の諸形質の間には有意差はみられなかつた。4. 花粉及び種子稔性は, 両親はいづれも良好であり, 略々90%以上の値を示した。之に対しF_1は正逆交雑共に両稔性の低下を示し, 花粉稔性に於いて60%以下, 種子稔性では30%前後に低下した。5. 両親の柱頭色は共に白色であるが, F_1のそれは鮮明な赤紫色を呈した。又種子形状はF_1はすべてジユズダマ型を示し, 卵形, 黒褐色, 硬質であり, ハトムギの長楕円形, 茶褐色, 軟質の特長は見られなかつた。育成したF_2個体の数が少なかつたが, その分離より, 之等はいづれも補促因子による作用と思われる。6. 成熟期に於ける風乾物の飼料分析の結果, 両親及びF_1の間には, 特に著しい増減がみられなかつたが, ヘテローシスによるF_1の収量の増加に併つて, 必然的に反当可消化養分収量は増大するものと思われる。7. F_1の全個体は圃場に於いて完全に越年した。即ち, ジユズダマの越年性がF_1に導入された為であり, 且つ越年後のF_1の生育は旺盛で, 再びヘテローシスを表わした。8. 本実験の結果, ハトムギとジユズダマの種間交雑に於いて, そのF_1植物の主要形質にヘテローシスを示し, 且つ, 越年性が附与され, 其他に形質の劣変化を認めなかつた事は, 飼料作物としてのCoix属の改良という見地より, 極めて有意義であると考える。, 1. The present paper deals with the results of investigations on the interspecific hybridization in genus Coix. This crossing was attempted between two Coix species : Hatomugi, Coix Ma-yuen ROMAN. (2n=20)×Juzudama, C. Lacryma-Jobi L. (2n=20) and its reciprocal combination. Now Hatomugi has been utilized for forage crops, but this crop is annual plant. On the contrary, Juzudama is perennial in growth and it has high resistance to bad conditions of environment. 2. In this interspecific hybridization the crossability in two crosses (Hatomugi×Juzudama and its reciprocal cross) were easy comparatively. That is, the percentages of seed set showed 43.08% and 50.30% respectively. The germinating percentage of F_1 seeds, obtained in this crossing, was inferior to Hatomugi (83.93%), but superior to Juzudama (45.31%). The percentages of F_1 seed germination were 68.81% and 57.14% respectively. 3. F_1 plants in this interspecific hybridization showed "Heterosis" for several characters. Namely, plant height, number of tillering, number of leaf, leaf width, leaf area, culm diameter and plant weight were vigorous as compared with both parents. Especially, in plant height, number of tillering, leaf width and plant weight the significant differences were recognized in statistically. In the early stage of development, all F_1 plants pointed out the heterosis. Heading date of F_1 plants was about 5th-10th August that is in the middle of the heading date of both parent plants. The ability of regeneration showed a more vigorous tendency in plant height and number of tillering than both parents. The significant differences were not recognized in statistically between the characters in both F_1 plants. 4. The pollen and seed fertility in F_1 plants were lower than both parents. That is, the fertility showed less than 60% in pollen and thereabout 30% in seed, in spite of the both fertility in parents showed more than 90%. 5. In this experiment, the inheritance in a few characters was observed. The stigma colour showed clear red-violet in all F_1 plants though both parents have white stigma. The character of seed riped on F_1 plant showed Juzudama type, that is ovate in seed shape, black-brown and hard seed coat. Although F_2 plants were scanty in this year, according to the segregation of F_2 plants, such phenomena will be explainable by complementary factors. 6. According to the chemical composition in dry samples at the ripenning stages, between the both parents and F_1 plants there were no difference remarkably. 7. All F_1 plants spent the rest of the year at the field. In the next year, the growth of F_1 plants was vigorously in compared with Juzudama that was perennial. 8. From these results mentioned above, it will be identified that the improvement of genus Coix as a forage crop is very significant, bacause the F_1 plants in this interspecific hybridization show heterosis and all F_1 plants show perennial type completely.

わが国に広く分布するCoix属のハトムギ(Coix Ma-yuen ROMAN.)とジユズダマ(C. Lacry ma-Jobi L.)の近縁関係を調べる目的で, 細胞遺伝学的方法によつて両植物の核型と, その雑種F_1植物における染色体の行動を観察した。ハトムギ及びジユズダマの根端細胞における体細胞染色体を, aceto carmineによるおしつぶし法によつて観察した。その結果, 両植物の核型を次の如く決定した。ハトムギ : K(2n)=20(2b)=2^A^m+2B^m+2C^m+2^cD^m+2^E^m+2F_1^m+2F_2^m+2F_3^m+(2G)^+(2H)^ジユズダマ : K(2n)=20(2b)=2^A^m+2B^m+2C^m+2^cD^m+2E^m+2F_1^m+2F_2^m+2F_3^m+(2G)^+(2H)^両植物の核型中第5染色体(E)において若干の形態変化が観察された。即ちハトムギでは第二次狭窄とみられるくびれが観察されたのに反し, ジユズダマでは全く発見されなかつた。E以外の染色体の形態及び大きさには顕著な差が認められず, 両核型には高い類似性が存在するものと思われる。花粉母細胞の減数分裂における染色体対合は, ハトムギ及びジユズダマでは夫々10IIを示したが, その雑種F_1においては観察総数の82%は10IIを示し, 他に9II+2Iが約14%, 4及び6Iも僅少ながら観察された。これらの現象は両植物の染色体間に部分相同性の存在を意味し, 之の主たる原因は核型のE染色体によるものであろう。以上の結果より, ハトムギ及びジユズダマの2種に関しては, 核学的に高い類似性を有するとみてよいが両植物のゲノムは完全に相同ではなく, 部分相同の染色体が存在すると考えられる。, 1. Cytological studies on genus Coix has ever been carried out by NIRODI (1955). But the karyotype and genome analysis for some species or varieties of the genus Coix have not been studied. With a view to conclude of affinity between Hatomugi (Coix Ma-yuen ROMAN.) and Juzudama (Coix Lacryma-Jobi L.), the authors have studied the karyotype of these plants and the chromosome behavior in meiosis of PMC's of the F_1 hybrid. Both Coix plants have twenty somatic chromosome number. 2. The chromosome structure were observed in the metaphase of somatic cell division of root tip cell. The karyotype of Hatomugi and Juzudama were determined as follows : Hatomugi : Coix Ma-yuen ROMAN.; C. Lacryma-Jobi var. Ma-yuen STAPF. K(2n)=20(2b)=2^A^m+2B^m+2C^m+2^cD^m+2^E^m+2F_1^m+2F_2^m+2F_3^m+(2G)^+(2H)^ Juzudama : Coix Lacryma-Jobi L. K(2n)=20(2b)=2^A^m+2B^m+2C^m+2^cD^m+2E^m+2F_1^m+2F_2^m+2F_3^m+(2G)^+(2H)^ As showed in these formulas of karyotypes, there would be differences the structure of chromosome "E". That is to say, there is no secondary constriction in chromosome "E" of Juzudama. All chromosomes except "E" of Hatomugi would be similar to the chromosome of Juzudama respectively in the shape and size. As a result of above observation, it would be recognized that the karyotypes of Hatomugi and Juzudama have high affinity. 3. The chromosome association in meiosis of PMC's of Hatomugi and Juzudama was shown 10II and their form were closed bivalent in most cases. In the F_1 hybrid (Hatomugi×Juzudama), 10II was observed in 82% of all dividing cells, but 9II+2I was about 14%, and few cells with 4I or 6I were observed. As to this phenomena, it would be recognized that the both parental plants have partially homologous chromosome and almost all univalents have derived from E chromosome. 4. From these cytogenetical observation mentioned above, we have arrived at the conclusion that Hatomugi and Juzudama have fairly high affinity in karyotype, but the genomes of them would be at least partially homologous.

トウモロコシの葯培養による半数体植物育成の可能性を検討するために, 1核期の花粉をふくむ葯を用いて, 変更Millerおよび変更Whiteの基本培地にauxinsならびにcytokininsを種々の割合に添加した培地に培養し, 培養初期における葯の形態的変化, カルス形成さらに器官分化の様相について追跡調査した。培養初期における葯形態の変化中, 変色枯死する葯はMiller培地で多く20∿40%である。逆に開裂葯はWhite培地で多く50∿64%に達し, 葯の肥大化はMiller培地上で10∿20%に達し, これらよりはいずれもカルス形成は認められない。培養後20日を経過した無変化の葯より, 後にカルス形成が認められる。カルス形成率は0.04%できわめて低い。カルスの形態は均一でなく, 肥大速度にも差異が認められるが概して緩慢である。カルスの移植培養によって根の分化が認められたが, 発根程度ならびにその速度は培養条件によって著しく影響されるが, 一般に伸長速度はおそい。半数性カルスならびに根の存在を確認することが出来ず, また茎葉分化が認められなかったが, 本実験の結果, トウモロコシのカルス形成ならびに根の分化は可能であり, 半数体植物育成の可能性を類推させた。, This experiment was made a trial for investigate possibility on induction of haploid plant by anther culture in maize (Zea mays L.). Several anthers with uni-nucleate stage of pollen from male flowers, 7∿10 days before heading, were placed on the medium. The basic media were prepared modified Whites medium and modified Miller's medium containing various concentration of 2,4-D, IAA and kinetin. The media were adjusted to pH5.8. Among the morphological variation of anthers placed on the media, anthers changed brown and died after a while were amounted about 20∿40% of all placed ones on Miller's media, and dehiscent anthers and enlarged ones were observed 50∿64% on White's media and 10∿20% on Miller's media respectively. Primordium of callus was formed in the ends of anthers inchanged in about 20 days after anther culture, and decided callus formation was recognized in extremely few anthers in 4∿8 weeks after anther placing. The percentage of callus formation was about 0.04%. The callus formed by anther culture had not uniformity in the size and colour, and generally the state of callus increased was very inactivity. Callus formed on several media were transplanted on modified Miller's media in supplement with various auxins and kinetin. Degree of rooting from callus and it's velocity of growth were susceptible to influences from the conditions of media. In general, state of rooting was very inactivity on all media and the optimum constituents of media for root differentiation were yet to be determined through result of above experiments. Roots with haploid number of chromosomes were well not ascertained and the differentiation of leaves and stem from callus were not recognized to the last of these anther culture. From these investigation mentioned above, it was recognized that it is difficult to make the haploid plant of maize by anther culture. Our experimental results show, however, that the callus formation and root differentiation from callus were successful. We expect to establish, therefore, available method for induction of haploid maize by improving the method of anther culture.

筆者らは現在改良試験を実施中であるCoix属のハトムギ, ジュズダマ及びそのF_1雑種, 更にその四倍体植物の花粉を, Zea属のトウモロコシ花粉と共に薬品処理による花粉膜の光学顕微鏡的観察と, Carbon Replica法の適用による花粉膜の表面微細構造の電子顕微鏡的観察を行い, 両者の比較を行つた。1.光学顕微鏡的観察 光顕像においては, 供試植物の花粉の間には, 花粉粒の大きさ以外に形態学的差異は観察されなかつた。発芽孔は一つであり, 花粉膜はextineが薄くintineが厚く観察された。また発芽帯周辺は一般に厚膜であり, 花粉の変形, 壌裂は極の方に多い。発芽帯には乳状突起が観察された。2.電子顕微鏡的観察 電顕像による花粉のextexineの微細構造は, 供試花粉ではいづれも微細なspineによつておおわれ, 各種間に明らかな差は認められない。ただCoix, Zea両属間にはspineの大きさにおいて, Coix属内の各種間には形状においてやや差が認められるようである。発芽帯の状態は, トウモロコシでは乳状突起の中心に, spineをもつ隆起部が発達し, ハトムギ及びジュズダマでは共にこの隆起部はなく, わづかなうねりをもち, なお乳状突起には不規則に少数のspineが点在していた。しかし, このspineをもつ隆起部は, F_1及び四倍体植物においては著しく発達していた。発芽帯の孔径は, 四倍体は二倍体に比して著しく大きかつた。一般にCoix属とZea属の花粉表面構造の間には, きわめて高度の類似性が認められた。, The morphology of pollen is investigated as a main section of palynology. In the present time the studies on the surface structure of pollen are paid special attention to make progress of the pollen analysis. The present paper deals with the results of microscopic and electromicroscopic investigations on the surface structure of the pollen membrane. The materials used in this studies are the pollen of Zea mays, Coix Ma-Yuen, C. Lacryma-Jobi, F_1 plant (C. Ma-Yuen×C. Lacryma-Jobi), 4x F_1 plant and 4x C. Ma-Yuen. The pollen used in the microscopic observation was treated by HCI and NaOH previously and electromicroscopic observation was based on the carbon replica method. 1. Microscopic observation : The morphological difference of pollens between the material plants was not recognized except the diameter of these pollen grains. The pollen of Zea and Coix plant are apaturate pollen similarly other gramineae plants. The extine of pollen membrane was thin but the intine was observed very thickly, These pollens have thick membrane around a germinal zone, for that reason the transformation and the bursting of pollen occurs near the pole of pollen, In germ pore of pollen grain the papilla was observed slightly. 2. Electromicroscopic observation : According to electromicroscopic observation, the extexine of pollen membrane was covered with fine spinules, there were no significant differences between the material plants on the surface structure of the pollen membrane. It is, however, obviously to the slight difference were recognized in the size of spine between the genus Coix and Zea, and in the shape of spine between the each plants in genus Coix. In the state of germ pore, there are fairly different between the material plants. In the germ pore of Zea pollen, the protrusion with fine spinules was well-developed in the central part of papilla, on the contrary, in the Coix Ma-Yuen and C. Lacryma-Jobi a few spines are dotted irregularly on the whole surface of slight concaved papilla. The protrusion with fine spinules was not found in the other pollen of C. Ma-Yuen and C. Lacryma-Jobi. But the protrusion was well-developed in the pollen of F_1 plant, 4x F_1 plant and 4x C. Ma-Yuen. The diameter of germ pore of 4x Coix pollen was larger as compared with that of 2x Coix pollen. As the results of these experiment it wes revealed generally that the similarity between the surface structure of pollen membrane of genus Coix and Zea was very closely.