モモのさし木繁殖に関する基礎的研究 I : 体内養分と発根との関係(農学部門)

モモの優良台木育成に際し, 繁殖技術としてさし木繁殖が有用であると考え, さし木繁殖に関する基礎的資料を得るため, 栽培品種を供試して, さし木適期, さし穂貯蔵条件および休眠枝ざしにおける体内養分の変化について検討した。季節的発根能力は6月および12月から1月にかけて成績良好であり, 体内C/N率も同時期において高いことが認められた。休眠枝貯蔵中には貯蔵期間が長くなるに従い, 一般に炭水化物の減少がみられ, 特にでん粉の減少が顕著であった。冷蔵は砂貯蔵より炭水化物の減少に及ぼす影響が大きかった。窒素は貯蔵期間中, 大きな変化は認められなかった。休眠枝ざしの発根率は大久保, 白桃において65.0%, 58.8%であったが, 白鳳は発根に至らなかった。白鳳では置床後の萌芽率が高いのが注目された。置床期間中, 体内C/N率は置床前半でさし穂の基部側が高い傾向があったが, 品種間では白鳳のC/N率が最も少ないのが他2品種と比べて特異であった。Recently, there have been interesting aspect about dwarfing rootstocks for peach as well as apple. Concerning with the propagation of such superior peach rootstocks containing the rootstocks which are resistant to root-knot species of nematode, the propagation by cuttings would be expected as available method. In this study, some experiments were made to obtain the fundamental informations for cuttings of peach. Among all seasons tried, the rooting ability was high in cuttings planted in June and in December-January, and it was also found that C/N ratio was high in scion of peach at the same season. The total carbohydrate contents in scion generally decreased according as storage continued, especially starch contents remarkable. The decrease in total carbohydrate contents was affected more markedly by refrigeration than by stratification with sand. The nitrogen contents remained relatively constant during planting period, though with some increase at the latter term. A rooting of 65.0% and 58.8% was obtained with \u27Okubo\u27 and \u27Hakuto\u27 cuttings respectively. In contrast, none of \u27Hakuho\u27 cuttings produced roots. High percentage of the sprouting in \u27Hakuho\u27 cuttings was observed at the first stage of planting period. It seems tendentious that C/N ratio in basal stem of cuttings showed higher value than in upper stem. Comparing with rooted \u27Okubo\u27, \u27Hakuto\u27 and non-rooted \u27Hakuho\u27, the latter had less C/N ratio

カキの発芽期以降における花器の発育について(農学部門)

カキ平核無の成木を用い, 発芽期より開花時までの花器(雌花)の発育過程を明らかにするため, 1973年4月初旬より組織学的な調査を行なった。その結果, 花の各器官はがく片, 花弁, 偽雄ずいおよび心皮の順に外側器官から分化形成された。それぞれの器官の発育をみると, 発芽時ではがく片および花弁の突起が観察されただけで, その他の器官分化は認められなかった。発芽時より5∿7日後には偽雄ずいおよび心皮の突起が分化し, 急速に各器官の発育が進み, 4月中旬には心皮突起の内側基部より胚珠の突起が分化しはじめた。4月下旬には珠心および珠皮が形成され, 珠心内で胚のう母細胞が分化した。その後花器の生長にともない, 開花のほぼ2日前に胚珠が完成した。また雄ずいは葯壁のみが形成され, タペート細胞および花粉は形成されなかった。以上のように, カキの花器は発芽時より各器官が分化し, 新梢の伸長にともない急速にその発育をとげ, 発芽時よりほぼ6週めで花器の形態が完成されることを認めたが, 他の果樹の花芽発育と比較して特異な発育を示した。The development of female floral organ in Japanese persimmon (cv. Hiratanenashi) has been followed from the time of sprouting until full bloom. The obtained results were as follows. The differentiation of each organ was initiated from the outer organs, namely in order of calyx, petal, staminodium, and carpel. Only calyx and petal primordia were observed at sprouting, but staminodium and carpel primordia differentiated about 5 to 7 days after sprouting. The ovule primordia were initiated on the infolded carpel edges near the base of the ovarian cavity in the middle of April, and the growth of them was more rapid. Integument, nucellus and embryo-sac mother cell were formed in the end of April. The formation of ovule was completed about 2 days before full bloom, but no differetiation of tapetum and pollen grains was observed in the staminodium. Thus, the formation floral organ in Japanese persimmon was completed about 6 weeks from the sprouting time