Abstract
This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.
본 실험은 항균효과가 있는 이산화염소($ClO_2$) 에 대한 장미 'Beast'의 절화수명 연장효과를 알아보고자 수행되었다. 실험은 보존용액처리와 침지처리로 구분하였다. 보존용액처리는 수돗물(tap water, TW), 증류수(distilled water, DW) 그리고 $ClO_2$ 2, 4, 6, $8{\mu}L{\cdot}L^{-1}$와 항균제와의 상대적인 처리효과를 알아보고자 8-HQS $200{\mu}L{\cdot}L^{-1}$를 처리하였다. 침지처리는 $ClO_2$ 50, 100, 150, 200, $250{\mu}L{\cdot}L^{-1}$를 60초 동안 침지 처리 후 DW로 옮겨 주었다. 절화수명 연장효과는 $ClO_2$ $4{\mu}L{\cdot}L^{-1}$의 보존용액 처리와 $ClO_2$ $200-250{\mu}L{\cdot}L^{-1}$ 침지처리에서 각각 13.8일과 13.5-13.7일로 가장 효과적인 반면, 8-HQS $200{\mu}L{\cdot}L^{-1}$ 처리는 식물체에 독성피해를 나타냈다. 생체중은 모든 처리구에서 시간경과에 따라 증가하다가 6일부터 점차 감소하였고, 수분흡수율은 증가하였다. 특히 절화수명이 짧았던 $ClO_2$ $8{\mu}L{\cdot}L^{-1}$와 8-HQS $200{\mu}L{\cdot}L^{-1}$ 처리구에서 대조구보다 생체중 감소율이 컸고, 수분흡수율은 낮았다. $ClO_2$ $2-8{\mu}L{\cdot}L^{-1}$와 8-HQS $200{\mu}L{\cdot}L^{-1}$ 처리구는 보존용액 내 박테리아 축적을 억제시켰으며, $ClO_2$의 잔존농도는 처리 2-4일 내 모두 소멸되었다.
