(1) Three kinds of chlorophyll mutants (chlorina, basi-viridis II and virido-albina) and three others, morphological mutants (early, slender and irregular-ear) of einkorn wheat were subjected again to gamma- and X-rays. Their radiation susceptibility was examined in X₁ and in X₂-seedlings.
(2) Radiation sensitivity of mutant strains in the X₁-generation, concerning germination or survival rate, plant height and fertility was not much different from that of the normals.
(3) In the X₂-generation the frequency of chlorophyll mutation in mutant strains was the same when their germination rate was good. On the contrary, it became low, when the percentage of non-germinating heads was high. Addition of radiation injury or additional gene mutation might be the cause of the variable viability in the X₂.
(4) Mutation spectrum of the mutated strains seems to be similar to that of the normal strain. About half of the chlorophyll mutants were albina.
(5) Mutations in one major gene seem to bring about a similar response to radiation as that of the normals.

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ギョウジャニンニク Allium victorialis L.subsp. platyphyllum Hultén の蕾をドクゼリ Cicuta Virosa L. の水抽出液 (100ccの蒸溜水中に生体量10gを浸けたもの) にて, 3時間, 4時間および20時間の処理をほどこし, 直ちに水洗後花粉母細胞の分裂の異常を観察した。
観察の結果, この水抽出液のおよぼす影響で最も顕著な現象は, 分裂の中期および後期にみられる染色体の粘着現象であった。
そのほか, 第1後期, 第2後期での染色体橋の形成, 遅滞染色体や断片の出現, 中間期の核における著しい空胞化および分裂中期での染色体の膨潤などがあげられる。
ドクゼリの水抽出液は分裂細胞, 特に分裂中期の細胞に強く作用し, 核分裂を抑制して以後の分裂行動に対して種々な異常を生ぜしめるものと考えられる。

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有毒植物のテンナンショウ (Arisaema japonicum), クサノオウ (Chelidonium majus) の水抽出溶液により, オオバナノエンレイソウ (Trillium kamtschaticum) の根端細胞を, さらにツクバネソウ (Paris tetraphylla) の胚珠壁細胞をも処理して, 分裂細胞における染色体異常を観察した。
1) Arisaema 抽出液処理により, 分裂中期および後期における染色体の stickiness, および分裂後期•終期における sticky bridge(s) が高頻度に観察された
2) 同じく Arisaema 抽出液処理により, 染色体の伸長, および細化の現象が観察され, これに関しては全染色体が均一に伸長するのではないように思われた。
3) Chelidonium 抽出液処理によっては, 分裂中期および後期染色体の stickiness, および終期における sticky bridge(s) のみが出現した。

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1. In the present research, the germination of F₂ seed, and the external characteristics, fertility and the number of somatic chromosomes of trigeneric triple F₂ hybrids (TperHRF₂) raised from (Triticum persicum×Haynaldia villosa F₁)×Secale cereale were studied.
2. 113 grains of F₂ seed were obtained from 18 F₁ individuals which were shown partially fertile, and all of the seed were sown in separate pots in October 1958 and 97 grains germinated and 87 of them matured (Table 1). The germination of F₂ seed varies with the each parent, and the percentage of germination has been shown to vary from 50 to 100 for the seedlings, or from 0 to 100 for the matured F₂ plants (Table 1).
3. As seen in Table 2, the number of somatic chromosomes of the 89 individuals of TperHRF₂ hybrids was found to vary from 38 to 58.
4. Some individual differences were observed in the external characteristics of the F₂ plants, even among the plants having the same number of chromosomes (Tables 3 and 4). The culm length of almost all of the F₂ tended to be inferior to that of the parental plant (F₁). And there seems to be no correlation between culm length and the number of chromosomes. The length of spikes and the number of spikelets per spike, in general, were superior to those of the parent (F₁), excepting some individuals which were somewhat inferior to those of the parent. The length of awns, the most of the F₂ which were raised from F₁ having 2n=26 chromosomes were superior to those of the parental plant (F₂), but in the other ones it was in general that they tended to be inferior to that of the parental plant (F₁). The spikelet density of the most of F₂ which were raised from the F₁ having 2n=28 chromosomes were superior to those of the parents (F₁), while in the remaining all the others were the same value or inferior to that of the parents. Generally speaking, the external characteristics of F₂ plants were somewhat inferior to that of the parental plants (F₁).
5. The external appearance of spikes of F₂ plants having 2n=38-46 chromosomes violently revealed rye characteristics more than that of Haynaldia and wheat, ond those other ones having 2n=47-56 chromosomes resembled more closely Haynaldia or wheat, because there are the differences of consisting of chromosomes between the former group and the latter.
6. As can be seen in Table 5, 21 in 69 F₂ plants show fertility though under natural selfing conditions it is not such a high percentage. And those values are progressively exceeding those of parental plants (F₁)

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