Effects of Cutting Time, Auxin Treatment, and Cutting Position on Rooting of the Green-wood Cuttings and Growth Characteristics of Transplanted Cuttings in the Adult Prunus yedoensis

This study was conducted to develop an efficient mass propagation method for the mature $Prunus$ $yedoensis$ Matsumura (43 to 58 years old). Cutting was conducted depending on cutting time, auxin treatments (IBA and NAA treatments mixed with talc powder), and cuttings position on shoots in a plastic house equipped with a fog system without heating. Rooted cuttings were transplanted to a nursery bed, and their growth characteristics were investigated in order to check whether the cuttings are successful or not for roadside tree planting. The average rooting rate was highly significant ($P$ < 0.0001) in all treatments: cutting on June 1st (61.4%) was more than two times greater in rooting rate than that on August 1st (23.6%); IBA 1,000 $mg{\cdot}L^{-1}$ (90.8%) and IBA 500 $mg{\cdot}L^{-1}$ (89.2%) showed much greater rooting rates than those of the other treatments; upper part of the cuttings treated with IBA 1,000 $mg{\cdot}L^{-1}$ showed the highest rooting rate, 96.7%. The interactions among treatments in the average rooting rate were also significant. There were significant differences ($P$ < 0.0001) among the auxin treatments in the survival rate of leafed cuttings transplanted to a nursery bed. The average survival rate was 46.5%, and IBA 1,000 $mg{\cdot}L^{-1}$ treatment was the highest in leafed cuttings 79.2%, but most of leafless cuttings were dead. There were significant differences ($P$ < 0.0001) among the cuttings, grafts, and in the seedlings height, diameter at root collar, the number of roots, branches, and leaves, etc., and the cuttings was the best. We can expect a possibility of mass propagation of improved $P.$ $yedoensis$ Matsumura and a high planting survival rate through the transplanting of cuttings to a nursery bed in which the cuttings should be the following conditions: cutting in June to July, use of the upper part of cuttings, IBA treatment, and rooting in August in a cutting-greenhouse equipped with a fog system.

왕벚나무 성목 녹지삽목에서 삽목시기, 옥신처리 및 삽수부위가 발근에 미치는 영향과 이식 삽목묘의 생육특성

왕벚나무 성목(43-58년생)의 삽목묘 대량증식 방법을 밝히기 위해 삽목시기별, 옥신처리별 및 삽수부위별로 자동안개관수장치가 설치된 무가온 비닐하우스에 삽목을 실시했으며, 삽목묘의 가로수 식재 성공여부를 검토하기 위해 발근된 삽목묘를 묘포장에 이식하여 생육특성을 조사하였다. 각 처리에 따른 평균 발근율의 분산분석 결과는 고도의 유의성($P$ < 0.0001)이 나타났다. 시기별 평균 발근율에서 6월 1일의 삽목(61.4%)이 8월 1일(23.6%)보다 2배 이상 높아 6월 1일이 적합한 시기로 나타났다. 발근율이 가장 좋은 옥신 처리는 IBA $1,000mg{\cdot}L^{-1}$와 IBA $500mg{\cdot}L^{-1}$ 처리에서 각각 90.8%, 89.2%로 나타났으며, 발근율에 대한 각 처리간의 상호효과($P$ < 0.0001)가 인정되었다. 삽수부위에서 상단부 + IBA $1,000mg{\cdot}L^{-1}$ 처리가 발근율 96.7%로 가장 높게 나타났다. 삽목묘의 묘포장 이식 활착률 역시 옥신처리간에 고도의 유의성($P$ < 0.0001)이 인정되었으며, 잎이 있는 삽목묘의 평균 이식활착률은 46.5%로 낮았으나 IBA $1,000mg{\cdot}L^{-1}$ 처리는 79.2%로 높았다. 그러나 잎이 없는 삽목묘의 이식활착율은 8.7%로 대부분 고사하였다. 활착된 삽목묘와 접목묘 및 실생묘의 생장특성을 비교한 결과, 생장(수고, 근원경), 뿌리수, 가지수, 잎수 등에서 고도의 유의성($P$ < 0.0001)이 나타났으며 삽목묘가 월등히 우수하였다. 본 연구의 결과는 자동안개관수장치로 안정적인 습도조절과 온도유지가 가능한 삽목실에서 6 - 7월의 삽목실시, 상단부 삽수의 선택, IBA처리 및 8월에 발근된 삽목묘의 묘포장 이식을 통해 개량된 왕벚나무의 대량증식과 성공적인 가로수 식재가 가능할 것이다.