본 연구는 차광과 온도가 분화 국화의 생육 및 개화에 미치는 영향을 조사하기 위하여, 차광(무차광, 30% 차광, 50% 차광)과 온도(주간/야간 28/20℃, 32/23℃, 36/26℃)가 조절된 인공기상챔버에서 자연단일상태로 재배된 ‘오렌지에그’의 생육 및 개화특성을 비교하였다. 그 결과, 30% 차광 조건에서 분화 국화 ‘오렌지에그’의 초장은 36/26℃에서 24.6cm로 가장 길었으며, 32/23℃에서는 23.0cm, 28/20℃에서는 19.6cm로 생육온도가 증가할수록 초장 신장이 촉진되었으나, 차광정도에 대해서는 유의적인 차이를 보이지 않았다. 분화 국화 ‘오렌지에그’의 개화반응 역시 주간/야간 온도 28/20℃에서는 단일 처리 23.4일 후에 발뢰하여 49.1일만에 100% 개화되었으나, 32/23℃와 36/26℃로 생육온도가 증가할수록 28/20℃에 비해 발뢰가 각각 4.1일과 11.4일, 개화는 각각 8.2일과 16.1일 지연되었으나, 차광정도에 대해서는 유의적인 차이를 보이지 않았다. 이와 같이 분화 국화 ‘오렌지에그’의 생육 및 개화반응에 미치는 영향은 차광에 비해 고온으로 인한 피해가 심각하게 나타날 수 있는 만큼 고품질의 분화 국화를 생산하기 위해서는 생산 시기별 온도 관리가 매우 중요하며, 특히 하계 고온기에는 적극적으로 차광하여 재배온실의 온도를 적정 생육온도에 가깝게 유지하는 것이 필요할 것으로 생각된다.

본 연구는 LED 광원의 파장이 분화 국화의 생육에 미치는 영향을 조사하기 위하여 22℃ 항온조건에서 주간 11시간, 야 간 13시간의 광주기로 조절된 폐쇄형 식물생장상에서 7주간 단일상태로 재배된 ‘오렌지에그’ 품종의 생육 및 개화 특성을 비교하였다. LED 인공광원은 청색광(444nm), 적색광(652nm), 그리고 청색광과 적색광, 백색광이 각각 2:5:1로 조합된 혼합 광을 사용하였다. 그 결과, 분화 국화 ‘오렌지에그’ 품종의 초 장은 적색광에서의 평균 9.43cm로 가장 길었으며, 청색광이 혼합광에 비해 짧았으나 통계적 유의성은 인정되지 않았다. 초폭과 엽폭은 초장에 대한 생육반응과 유사하게 적색광에서 가장 크게 신장하였고, 청색광과 혼합광에서는 유의적인 차이 를 보이지 않았다. 엽수와 엽장은 혼합광보다 청색광과 적색 광 등 단색광에서 더 많고 길었다. 분화 국화 ‘오렌지에그’ 품 종의 개화특성의 경우에는 청색광과 적색광, 혼합광 모두 단 일처리 16~17일 이후에 화아분화가 완료되어 발뢰가 시작되 었으나, 적색광과 청색광 하에서 생육한 국화는 화아발달이 정상적으로 이루어지지 않아 최종 개화까지 이루어지지 않았 고, 혼합광 하에서 생육한 국화만 단일처리 5주 후에 정상적 으로 개화되었다. 따라서 식물공장에서 분화 국화를 생산하기 위한 인공광원으로는 청색광과 적색광, 백색광으로 구성된 혼 합광을 사용하는 것이 가장 유용하리라고 판단된다.

Different laboratory strains of Drosophila melanogaster are reported to differ considerably in their physiology, behavior, and life-histories, due to their adaptations to different laboratory conditions. Recent advances in insect aging research have highlighted the importance of protein:carbohydrate (P:C) balance as a key dietary determinant of lifespan and other components of fitness, but it remains unexplored whether P:C balance affects the fitness-related traits of D. melanogaster in a strain-specific manner. The purpose of this study was to compare the life-history consequences of six different laboratory strains of D. melanogaster (three Canton-S substrains, w1118, yw, and Oregon-R) allocated to four synthetic diets differing in P:C ratio (1:16, 1:4, 1:1, or 4:1). Five components of fitness (lifespan, fecundity, larval viability, development time, and body mass) were recorded from flies maintained at 25oC under L:D 12:12 photoperiod. All strains exhibited qualitatively similar responses to dietary P:C balance, with the increase in P:C ratio being associated with shortened lifespan and improved egg production. In all strains, fly larvae confined to P:C 1:16 suffered high mortality, retarded growth, and reduced body size. As indicated by significant diet×strain interactions for all measured fitness components, the magnitude of such diet effect varied among different laboratory strains in D. melanogaster. Possible explanations for such strain differences are discussed.

Diets influence lifespan and reproduction in insects, but little is known how temperature modulates the impacts of diet on these two key fitness components. Here we examined the interactive effects of temperature and nutrient balance on lifespan and egg production rate in Drosophila melanogaster. Newly emerged adult D. melanogaster were allowed to feed ad libitum on one of eight chemically defined diets differing in P:C ratio (1:16, 1:8, 1:4, 1:2, 1:1, 2:1, 4:1, or 8:1) under one of six ambient temperatures (13, 18, 23, 28, 31, or 33℃). For both males and females, lifespan was longest for D. melanogaster fed on P:C 1:16 diet at 13℃ and shortened as both temperature and P:C ratio increased. As indicated by a significant temperature-by-diet interaction for lifespan, the diet effects on lifespan were more pronounced at lower temperatures than at higher temperatures. Egg production rate was maximized on P:C 4:1 diet at 28℃.

Temperature can affect the ability of insects to tolerate prolonged period of food deprivation through altering the amountof energy storage, the speed of energy expenditure, or the threshold energy storage for survival. In this study, we examinedthe mechanistic basis of the temperature-dependence of starvation resistance in Drosophila melanogaster. Starvation resistancedecreased as the temperature experienced during starvation rose from 18 to 28 ̊C. This warming-mediated decrease instarvation resistance was due to accelerated energy expenditure. However, the threshold energy storage for survival wasnot affected by starvation temperature. Exposure to warm temperatures during feeding led D. melanogaster to accumulatemore energy reserves and thus to become more starvation resistant. This study highlights the important role played bytemperature in shaping the phenotypic responses of insects to starvation.

This study was conducted to investigate the anti-bacterial effect of chlorine dioxide (ClO2) on extending thevase life of Gerbera jamesonii ‘Jenny’ which was first bredin Korea in 2012. Compared to commercialized biocides,ClO2 had been proved significantly effective for extendingthe vase life of cut gerbera flowers, equally with sodiumhypochlorite, silver nitrate, and 8-hydroxyquinoline sulfate.No bacteria were detected in the vase solutions treated withClO2 and these commercialized biocides on day 6 aftertreatment. But there were no significant differences on thevase life among the three ClO2 concentrations: 2, 5, and10μL•L−1. The ClO2 concentrations were rapidly decreasedon day 2 after treatment regardless of peduncle existence.Nevertheless, the antibacterial effect of ClO2 was main-tained up to day 6, indicating that the initial antibacterialeffect of ClO2 was a key factor for extending the vase life inthe gerbera flowers. The study results verified the antibacte-rial effect of ClO2 on prolonging the vase life of Gerberajamesonii ‘Jenny’ and demonstrated that appropriate ClO2application can prolong the postharvest life of cut gerberasvia its antimicrobial effect.

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.