1. あさがほ (Pharbitis Nil) の種子色の遺傳實驗により、種子色に關與する遺傳因子を明にし、次で、若干の生理化學的實驗により、それ等遺傳因子が如何なる物質に關與し、且、それ等因子に基き如何なる化學變化が、種子色の生成に關して、營養細胞内で行はれるかを幾分なりとも究むる事が出事た。
2. 黒種子、茶種子、白種子相互の間の交配實驗の結果は、それ等相互の遺傳關係が黒種子は茶種子并に白種子に、茶種子は白種子に優性であると云ふ爾來の研究結果を裏書した、且、これが副證と考へられる茶種子、白種子間の一交配のF2に於て、茶種子と白種子が3:1の比に分離した結果を與へた實驗が行はれた。
3. 黒種子の種皮の表皮細胞列に黒褐色の色素が存し、その直下の細胞列には淡褐色の色素が存するが、茶種子に於ける兩細胞列には何れも淡褐色の色素のみ存し、又、白種子に於ては兩細胞列に何れも、かゝる色素を存せぬと云ふ檢鏡的結果を得た。
4. 酸化酵素の各種子の種皮組織内に於ける分布が研究され、oxidase は白種子以外の有色種子に存する事、peroxidase は黒種子及びそれより分離きれた白種子には存するが、茶種子には存せぬと推定され又、茶種子より分離された白種子には存せぬ事が明にされた。
5. 生理化學的實驗の結果は、種子の色素は phlohaphen で、その chromogen は化學組成未知の pseudobase であつて、該物質は黒種子、茶種子、白種子の各種皮組織に含まれ、それが oxidase, peroxidase の如き酸化酵素により、酸化されて種子の色素が生成されるものと考へる。
6. 種皮組織に於ける phlobaphen 并に酸化酵素の分布状態と phlobaphen の chromogen 并に flavon の存否の檢定の結果と遺傳實驗の結果とを考へ併せて、次の如き種子色の生成に關與する遺傳因子を假定する。
C'……Phlobaphen の chromogen に關與する因子
C^a……flavon に關與する因子
O'……oxidase に關與する因子
O……peroxidase に關與する因子
C^a, O'兩因子間には完全リンケーヂがある。
7. 是等因子に基く、種皮組織の營養細胞内に於ける酸化作用はBACH氏等の所謂、酸素活性化説に基いて考察されて、合理的に説明される。

抄録全体を表示

The triploid hybrid employed in this study has arisen from the cross between Celosia argentea L. (n=36, Fig. 2) _??_ and C. cristata L. (n=18, Fig. 1) _??_.
At the earlier stage of the heterotypic metaphase in P. M. C., all chromosome elements are scattered throughout the cell (Fig. 3). As the stage draws near to the metaphase, bivalents move toward the metaphase plate, and univalents have a weak tendency to move toward the plate (Fig. 4). At the metaphase all bivalents arrange on the metaphase plate and some univalents are present in the metaphase plate with bivalents, but most of the univalents are found at some distance from plate (Fig. 5). In this stage, 18 univalents are often counted in a side view, but it is usual that the number of univalents does not reach expected number. At the polar view of metaphase 36 chromosome elements are counted, but univalents are not distinguished from bivalents (Fig. 6). At the anaphase all univalents are distributed at random to the opposite poles together with the divided halves of bivalents (Figs. 7-9). The univalents have no longitudinal splitting in this stage.
Chromosomes lagging behind in the anaphase are frequently observed in the interkinesis (Fig. 11). These lagging chromosomes either form a microcyte in the tetrad formation (Fig. 16), or are lost in the cytoplasm.
At the metaphase of the second division all dyad chromosomes arrange themselves in strikingly regular fashion in each of the two daughter nuclear plates (Fig. 12). At the polar view of this stage 27 dyad chromosomes are often found in both daughter cells (Fig. 13). Chromosomes lagging in the first division are also clearly found in the second division (Fig. 14). In the anaphase, chromosomes farming the second division plate divide longitudinally and pass to the opposite poles (Fig. 15).
The chromosome behavior during meiosis of the triploid Celosia hybrid is very markedly similar to that which takes place in the Drosera hybrid (ROSENBERG, 1909).
The F₁ hybrid of C. argentea × cristata contained 54 chromosomes in diploid number, this being the sum of the haploid number in both parents, which had, respectively, n=36 and 18. In the F₁ plant, the chromosomes conjugate in such a manner that the 18 C. cristata chromosomes united with 18 of those from C. argentea, the remaining 18 of the latter being left as unpaired chromosomes. 18 bivalents divide in the normal way throughout both divisions. But 18 univalents distribute to the opposite poles at random without longitudinal splitting in the first division, and they divide longitudinally in the second division.

抄録全体を表示

一) 普通の種子の形成に就て。
イ) 胚嚢母細胞の第一回の核分裂が異型的で、單數染色體は12である。
ロ) 完成された胚嚢の構造は、全く正常の通うであう、胚乳の形成は遊離核型によつてなされる。胚乳細胞の核分裂に於ては、トリプロイドの染色體を認め得る。
ハ) 胚珠には最初から珠皮を缺いて居る。珠心組織は胚乳に依つて次第に吸收されてしまふから、此の植物の種子の胚乳は全く裸である。
ニ) 裸胚の形成に就て。
イ) 裸胚は授精された卵細胞から、胚乳の形成を伴ふことなしに、生ずるのである。
ロ) 珠心組織は胚の成長につれて、次第に吸收きれるから、出來上つた胚は、完全に裸になつて外部に露出する。

抄録全体を表示

1. The inheritance of seed-coat colour in the water melon (Citrullus vulgaris SCHRAD.) is preliminarily reported in this paper.

抄録全体を表示

1) The original fatuoids used in this work were supplied by Dr. C. L. HUSKINS, who had already studied them.
2) Heterozygous fatuoids from three strains, H58, H20 and H93 segregated in the following generation normals, hetero- and homozygous fatuoids in a 1:2:1 ratio. The genetic results confirmed practically HUSKINS' observations.
3) Many segregates from each phenotype were cytologically studied. In all of them except 4, normal 21 bivalents were generally counted at the heterotypic metaphase in PMC. On the other hand, uni- tri- and tetravalent chromosomes were observed in a few PMC from some of these plants. The statistical counts of their occurrence are shown in Tables 2-4. From these results we can see that meiotic abnormalities occur independently of the phenotypic character of the grain, and appear to be not directly transmitted from generation to generation. The chromosome irregularities may be caused mainly by the lack of cytological equilibrium and by the polyploidy in Avena.
4) There were found to be 5 segregates with 41 chromosomes that arose in each of the phenotypes. They were probably produced through meiotic irregularities in the parent plants.
5) From them 2 heterozygous fatuoids, H58-12 and H20-35, segregated dwarf homozygous fatuoids, heterozygotes and normals in a ratio of ca. 1:1.5:0.1. The progenies from H58-12 were extensively studied. The dwarf homozygous fatuoids had 40 somatic chromosomes, but the formation of bivalents was much reduced, 0-10II, being counted so far observed. Therefore they were completely sterile. A few of low fertile homozygous fatuoids were found. Their chromosome combination might be 20II+fc1I Heterozygous fatuoids had 20II+1I. Their fertility varied widely, probably owing to the external conditions (Tables 7 and 8). Normal segregates appeared to be quite normal in the cytological and morphological features as well as in fertility. The abnormal segregation ratio is discussed with special reference to the cytological behavior.
6) The 3 other plants with 41 chromosomes lacked different chromosomes, which do not bear factors for the fatuoid and cultivated type of the grain characters.
7) Three main hypotheses on the origin of fatuoids are discussed from the genetic and cytological points of view.
8) Basing on the genetic and cytological behavior fatuoids are classified into two main groups. The first series contains fatuoids produced by the mutation of a gene complex in the c-chromosome. The common fatuoid belongs to this class. Fatuoids of the second series arose through chromosome aberrations. Owing to the deficiency of a whole chromosome the meiotic and genetic features are very abnormal.

抄録全体を表示

1. The self-pollination of female intersexual hemps was repeated for several generation.
2. No male plants appeared in their progeny.
3. The frequency of the production of female intersexes increased generation after generation until not a single female plant appeared.
4. The gradual decrease in germinating percentage was very remarkable.
5. From these facts it is probable to say that the intersexuality is influenced not only by environmental conditions but by genetic factors.

抄録全体を表示

1. From the seed obtained from selfing of intersexes in Spinacia oleracea and Melandrium ruburum, there grew only females and intersexes but none of males.
2. These facts show that the intersexes thus treated have female-like constitution in their genetic elements

抄録全体を表示