Effects of Uniconazole Treatment on the Growth and Floweringof Potted Chrysanthemum indicum L.

Uniconazole 농도가 분화용 감국의 생육 및 개화에 미치는 영향

This study was carried out to investigate the effects of uniconazole treatment on the growth and flowering of potted Chrysanthemum indicum L. for high quality pot plant production. Uniconazole was drenched at 0.05, 0.01, or 0.15 mg a.i./pot at 14 days after planting (DAP) of rooted cuttings. Simultaneously the short-day treatment (SDT) and pinching were adapted. The same amount of uniconazole (0.05 mg a.i./pot) was spilt drenched at once, twice, and three times, respectively, at 1 week interval. Uniconazole markedly reduced plant height, branch length, and stem diameter. Plant height was reduced linearly with increasing uniconazole concentration at 0.05, 0.01, or 0.15 mg a.i./pot up-to 41.6%, 52.5%, and 58.5%, respectively. In 0.05 mg a.i./pot, the number of branches greatly increased and plant height of 22.6 cm was adequate for pot plant. However, higher concentrations (0.10, 0.15 mg a.i.) were not suitable for production of high quality pot plant (17.0, 14.8 cm, respectively). Pinching and SDT decreased the number of days to visible bud, while uniconazole treatments delayed days to visible bud by 5-9 days compared with pinching and SDT. Number of visible buds was highest at 0.05 mg a.i./pot uniconazole treatment. However, flower diameter was decreased by uniconazole treatment, resulting in compact form. Number of stomata was increased by uniconazole treatment. The length of vascular tissues of uniconazole-treated plants ($11.2{\mu}m$) was smaller than that of non-treated plants ($15.0{\mu}m$, and the size of xylem vessel was also decreased. Uniconazole treatment at 0.05 mg a.i./pot at 14 DAP with pinching and SDT were recommended for pot plant production of C. indicum L.

본 연구는 uniconazole 농도가 감국의 생육 및 개화에 미치는 영향을 구명하여 가장 효과적인 방법을 찾음으로써 양질의 분화용 감국 생산을 위한 기초자료를 얻고자 실시되었다. 삽목 발근묘를 정식 후 2주째 적심하고 uniconazole을 농도별로 토양관주하였으며, 같은 농도(0.05mg a.i./pot)를 1회, 2회, 3회로 나누어 관주하고 동시에 단일처리와 적심처리를 행하여 감국의 생육 및 개화반응을 살펴본 결과, uniconazole을 0.05, 0.10, 0.15mg a.i./pot로 증가시킴에 따라 초장은 41.6, 52.5, 58.5%로 감소되었다. 측지수는 0.05 mg a.i./pot 처리구에서 가장 많이 증가되었으며 초장(22.6cm)도 18cm 화분에 적합하였다. 그러나, 높은 농도(0.10, 0.15mg a.i./pot)는 초장(17.0, 14.8cm)이 지나치게 짧아서 적합하지 않았다. 단일처리와 적심처리를 수행하는 경우에는 가시적인 화아발생시까지의 기간을 단축시켰지만, uniconazole 처리에 의해서는 적심과 단일처리시의 효과를 5~9일까지 지연시켰다. 화아수는 0.05mg a.i./pot에서 가장 많은 경향을 보였으나 꽃직경은 uniconazole 처리시에 감소하는 경향을 보여 꽃이 작고 많은 형태가 되었다. 또한 0.05mg a.i./pot를 1회에 처리한 경우에 화아발생시까지의 기간이 비교적 짧았으며, 화아수도 증가하였다. 따라서 정식후 2주째 적심과 단일처리 후 uniconazole 0.05mg a.i./pot를 1회 토양관주함으로써 화분과 균형을 이루는 초장을 얻을 수 있으며, compact type의 분화를 생산할 수 있을 것으로 판단되었다.