蕓薹種子の発芽に就て
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1) If we preserve rape seeds (B. Napella CHAIX.) in the laboratory in closed glass bottles, they retain their germinating capacity perfectly for 5 years. None of the seeds, however, can germinate when they are preserved more than 7 years. 2) The percentage of germination of the new seeds (preserved less than 2 years) is fairly high at room temperature. At 32℃ the percentage decreases markedly, and none of them germinate at 38℃. On the other hand old seeds (preserved 2-5 years) germinate well at 32℃, and in some cases high percentages of them can germinate even at 38℃. 3) Seeds taken at about 30 days after flowering were still in the milk stage. They germinated slowly, and the final percentages obtained were 95% in the green house and 56% in the thermostat at 32℃. 4) Seeds taken at about 40 days after flowering were provided with light green cotyledons. Though results came slowly, too and 74 percent of such seeds germinated respectively in the green house and in the thermostat at 32℃. 5) Seeds taken at about 50 days after flowering contained fully developed embryos The germinating capacity of the seeds decreases markedly in this stage, showing only 8 and 46 percent germination respectively in the thermostat at 32℃, and in the green house. The removal of the seed coat does not increase the percentage of germination of such seeds at 32℃. Alternating temperatures are fairly effective to break this peculiar kind of dormancy. 6) In 60 to 70 days when preserved at 4℃. the 50 days old dormant seeds became capable of germinating completely at 32℃. 7) The coats of the seeds about 6o d a ys old first show brown pigment. The embryo in this stage of development is no longer dormant, and if the coat is taken off it starts germination immediately at 32℃. When the coat is kept intact, however, the seed fails to germinate at high temperatures such as 32℃ and 38℃. Proper alternating temperatures can, however, induce complete germination of such seeds. 8) The 70 days old seeds are completely ripe. Most of such seeds with the coats intact fail to germinate at high constant temperatures. Cureing at 4℃ promotes the germination at high temperatures. 9) When we reserve 40-50 days old seeds with the silique for one year, they become able to germinate well at 32℃. Such preservation is, however, only slightly effective for 60-70 days old seeds. 10) When we take the perfectly ripe seeds out of the silique and preserve on a tray for a year, they become able to germinate well at 32℃. The preservation of such seeds in a closed glass bottle is less effective to induce the germination at the high temperatures. 11) The germination of the completely ripe new seeds at high temperature is caused by the treatments with concentlated sulfuric acid, absolute alcohol, and hot water, all these agents are supposed to affect only the seed coats. 12) The amount of water absorbed by the new seeds on the high temperature bed is slightly greater than the amount taken by the old ones at the same temperature. 13) The increase of oxygen partial pressure is only slightly, if any, effective for the germination of the new seeds. The decrease of its partial pressure clearly hinders the germination. The seeds, however, can germinate well in 32℃ water, and still more so when a small amount of H2O2 is added. 14) Some amount of CO2 hinders the germination of the seeds, but it will never induce the secondary dormancy. 15) The poor germination of the new rape seeds at high temperatures is caused probably by the accumulation of CO2 or other organic toxic substances in the seed tissue. The higher the germination temperature, the more quickly such substances will be produced to accumulate within the seed. When the seeds is in water such substances seem to escape through the coat more quickly than when it is on wet paper.1). 蕓薹種子は瓶中に密閉して室内に貯藏する時は, 收穫後滿五ヶ年間は完全に發芽力を維持するも滿七ヶ年を超えたるものは全く發芽せざりき。2). 貯藏滿ニヶ年以内の種子は室温にては高牽の發芽をなせども, 發芽床の温度三二度を超ゆる時は發芽率著しく低下し, 三八度以上に於ては全く發芽せず。然るに貯藏滿ニヶ年を超ゆる時は, 三二度に於ても極めて容易に發芽し, 三八度に於ても兩高傘の發芽を示すことあり。3). 開花後約三〇日の乳熟種子は温室に於て95％の發芽を示し, 三二度に於ても尚56％の發芽を示せり。發芽一般に不齊一なり。4). 開花後約四〇日の種子は緑色を呈せる子葉を含み温室に於て殆ど全部發芽し, 三二度に於て74％の發芽を示せり。發芽一般に不齊一なり。5). 開花後約五〇日にして種子は完全に形成せらる, 種子は此熟度に於ては發芽牽著しく低下し, 種皮を除去せるものを四〇日間三二度に保つも全く發芽するを得ず, 即種子は一度休眠するものと考へらる, 斯かる休眠種子と雖も是が毎日適當なる温度の變化に遭ふときは相當高率の發芽を示すものなり。6). 上記休眠種子は濕潤四度に於ける貯藏六〇乃至七〇日に及べば, 定温に於ても尚全部發芽するに至る。7). 開花後約六〇日にして種皮既に著色せる種子は既に休眠を脱し, 種皮を剥離する時は三二度にて全部直ちに發芽するを得, されど此熟度に至れば種子は著しく高温に於ける發芽力を失ひ, 三二度及び三八度にては殆ど發芽せず, されど適當に變温する事により好く全部發芽せしむる事を得。8). 開花後約七〇日にして種子は完熟す, 斯かる種子は種皮を剥離するに非ざれば定温特に高温に於ては殆ど曹發芽せず。濕潤四度に貯藏する時は高温に於ける發芽を容易ならしむる事を得。9). 開花後四〇日乃至五〇日なる未熟種子を一ヶ年間莢の儘貯藏する時は, 好く高温(三二度)に於て高率の發芽をなすに至る, されど開花後六〇日乃至七〇日に採集せし種子は, 斯かる貯藏によりて僅に高温に於ける發芽率の上昇を示せるに過ぎず。10). 完熟種子は是を脱粒し種子盆上に貯藏する時は, 次第に高温に於ける發芽能力を増加し, 一ヶ年目には三二度に於て約80％の發芽を示すに至る, されど是を密閉瓶中に貯ふる時は, 高温に於ける發芽遙かに盆上に貯藏せしものに劣る。11). 完熟新種子の高温に於ける發芽は, 種皮剥離及び種皮に影響すべき濃硫酸無水アルコール又は熱湯處理等によりて完全に誘致するを得。12). 高温に於ける蕓薹種子の吸水を檢せるに, 新古種子の間に殆ど差違なきも, 寧ろ新種子は古種子に比し吸水容易なるが如く觀ゆ。13). 高温發芽床中の酸素の分壓を増加するも殆ど新種子の發芽率の上昇を來さず, されど是を減少するときは明に發芽率を低下す, 種子を高温水中に置く時は高率の發芽率を示し,少量の過酸化水素を加ふる時は殆ど全部發芽す。14). 發芽床中の炭酸瓦斯を増す時は種子は發芽不能となるも, 高温となるに從ひ多量の炭酸瓦斯に堪ゆ, されど二次的休眠を來すことなし。15). 高温に於ける蕓薹種子發芽率低下の原因は, 新種皮が種子内の炭酸瓦斯其他有害成生物の逸出を阻ぐるに因るもの信ず, しかして是を水中に置く時は, 高温に於ても發芽容易なるは, 水を介して是等有害物質の逸出速なるに閃るものならん。
- 九州帝國大學農學部の論文
- 1930-05-00
九州帝國大學農學部 | 論文
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