Abstract
In order to investigate the difference of rootability between 15 clones of Populus alba${\times}$glandulosa selected based on the growth performance, rooting of cutting experiments with these 15 clones were conducted at the nursery for six years from 1970 to 1975. Cutting experiments in a temperature controlled incubator in which the temperature of the cutting bed were set to $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ were also performed. Along with these experiments air layering experiments were performed to compare with the rootabilities obtained from nursery trial. The results obtained so far could be summarized as follows. 1. The best rooting clones were 65-22-4 and 65-22-11, and the average rooting percentages of these two clones for six years were 76.7%, and 72.9% respectively. The poorest rooting clone was 66-6-8 showing average rooting percentage of 45.8%. 2. The middle class of rooting percentage was ocuppied by the clones; 66-14-29, 66-14-93, 66-25-5 and 67-6-3, and the range of their rooting percentage was 60~69% on average. 3. The rooting performances observed through the nursery, the incubator and the air layering experiments were almost the same with exception of few clones. 4. P. alba${\times}$glandulosa showed the best rooting percentage at the cutting bed of $20^{\circ}C$ 5. The most roots, i.e. 78.5% of root per cutting were developed from the bottom part of the cutting shoot. 6. Adventitious and call use roots could observe in the cuttings.
Populus alba${\times}$glandulosa $F_1$의 생장(生長)이 우량(優良)한 15개체(個體)를 선발(選拔)하고 이들을 증식(增殖)하여 이루워진 삽목발근율(揷木發根率)을 구명(究明)하기 위하여 1970년부터 1975년까지 6년간(年間) 포지(圃地)에서 삽목활착율(揷木活着率)을 조사(調査)하는 동시(同時)에 이를 뒷받침하기 위하여 Incubator 내(內)에서의 clone간(間)에 삽목발근율(揷木發根率)과 공중취목(空中取木)에 의한 clone간(間)의 발근능력(發根能力)을 조사(調査)하였으며 또한 삽목상(揷木床)의 온도(溫度)를 $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$로 하였을때 삽목발근력(揷木發根力)을 조사(調査)한바 다음과 같은 그 결과(結果)를 얻었다. 1. 삽목발근율(揷木發根率)이 가장 높은 clone은 65-22-4, 65-22-11으로서 6년간(年間)의 평균삽목발근율(平均揷木發根率)은 각각(各各) 76.7%와 72.9%이였으며 삽목발근율(揷木發根率)이 가장 낮은 clone은 66-6-8로서 발근율(發根率)이 45.8%이였고 2. 선발개체중(選拔個體中) 66-14-29, 66-14-93, 66-25-5, 67-6-3등(等)은 삽목발근율(揷木發根率)이 평균(平均) 60~69%로서 발근력(發根力)이 중간정도(中間程度)이였다. 3. 포지(圃地)의 삽본발근율(揷本發根率)과 Incubator 및 공중취목(空中取木)에서 얻은 clone간(間)의 발근능력(發根能力)은 몇 clone을 제외(除外)하고는 거의 같은 결과(結果)를 나타내었다. 4. P. alba${\times}$glandulosa $F_1$의 삽목(揷木)에 있어서 삽목상(揷木床)의 온도(溫度) $20^{\circ}C$일때 가장 삽목발근율(揷木發根率)이 높았으며 발근최적온도(發根最適溫度)로 인정(認定)되었다. 5. 삽수부위별(揷穗部位別)로 뿌리발근율(發根率)을 보면 뿌리의 78.5%가 삽수(揷穗)의 하단부(下端部)에서 발생(發生)하였다. 6. 삽수(揷穗)의 근(根)은 부정근(不定根)과 calluse근(根)이 있다.