メタセコイアさし木における発根に及ぼすC, N含量の季節的変動に関する考察 (第1報)

Abstract

メタセコイアさし木における発根とさし穂のC, N含量を月毎に調査し, 発根とC, N含量の季節的変動と, これら相互の関係を検討した｡ その結果の概要を示せばおよそ次のとおりである｡ 1. カルス形成率とC, N含量とのあいだに相互関係はみられなかつた｡ 2. 枯死率とC, N含量とのあいだにも相互関係はみられなかつたが, カルス形成率のひくい場合には枯死率がたかくなつており, 枯死率とカルス形成率とのあいだには, ある程度の関係があるように思われた｡ 3. 発根率は母樹の成長期間中においてはCの含量が多いほど, たかい傾向があつた｡ 成長休止期間中は両者のあいだに相互関係はみられなかつたが, これは温度がひくかつたためであろうと思われた｡ 発根率とNの含量とのあいだの関係については一般にNの含量が多い場合に発根率がたかい傾向があつた｡ 4. 発根率とC-N率とのあいだには相互関係はみられず, C, Nの絶対量の多い場合に発根率がたかかつた｡ 5. 発根根数の季節的変化は, ほとんどみられず, C, N含量との相互関係はみられなかつた｡ 6. 根長はC, Nの絶対量の多い場合にながい傾向があつた｡

This report deals with the result of the experiments on the monthly variation of the rooting responses and the C, N contents of cuttings of Metasequoia glyptostroboides Hu et Cheng. The outline of the experimental results is as follows; 1. There was no clear correlation between the percentage of callused cuttings and the C, N contents in cuttings. 2. There was no correlation between the percentage of blasted cuttings and the C, N contents in cuttings. 3. In the growing season of mother tree, a tendency was recognized that the percentage of rooted cuttings was high when the C, contents were high in cuttings. In the rest of the growing season of mother tree, there was no clear correlation between the percentage of rooted cuttings and the C, contents in cuttings. The too low temperature was considered to be the reason. With regard to the relation between the percentage of rooted cuttings and the N, contents in cuttings, a tendency was generally recognized that the percentage of rooted cuttings was high when the N, contents were high in cuttings. 4. There was no clear correlasion between the percentage of rooted cuttings and the C-N ratio in cuttings. It tended to be high when the absolute quantity of the C, N contents was high in cuttings. 5. It was recognized that the number of roots per rooted cutting was almost the same in all seasons. There was no clear correlation between the number of rooted cutting and the C, N contents in cuttings. 6. It was generally recognized that the total length of primary roots per rooted cutting was long when the absolute quantity of the C, N contents was high in cuttings.