This experiment was carried out to determine the effect of different spectrum conversion greenhouse films (red, blue, red+blue) to changing microclimate and subsequent effect on growth and quality of lettuce (Lactuca sativa L.), tomato (Solanum lycopersicum L.), and melon (Cucumis melo L.) Transmission of PAR (photosynthetic active radiation, 400-700 nm) under red, blue, and blue+red (BR) films was higher by 7.2, 7.6, and 5.8%, respectively, as compared with control greenhouse film. Light transmission in the 300-1100 nm wave band was 91.6% and 91.3% under red and blue films, respectively, compared to 86.4% under control film. Mean daytime temperature in greenhouse was slightly higher in red and blue film and mean night time temperature was higher in BR film. There were no significant differences in relative humidity among the films. Number of leaves and plant fresh weight of lettuce were higher under BR film. Total number of marketable tomato fruits was greater under blue and BR film and fruit weight was heavier under red and blue film compared to control film. Under BR and red film melon fruit weight was increased by 140 g and 80 g respectively, as compared to control film. Sugar content in melon and tomato fruits was not affected by covering films.

LED 보광 재배에 따른 딸기‘대왕’과‘설향’품종의 과실품질과 생산량을 확인하기 위하여 11월 10일부터 3월 20일까지의 생육기간 동안 각각의 LED 광인 청색, 적색 그리고 혼합(청색:적색= 3:7) 광을 17시부터 23시까지 75±5 μmol·m-2·s-1의 광량으로 조절하여 전조하였다. 겨울철 딸기 전조 재배에 주로 이용되고 있는 백열등을 대조구로 사용하였다. 딸기 두 품종에 있어, 생산량은 청색 LED 광에서 증가하였고, 과실 경도와 당 함량은 3종류의 LED 광 모두에서 향상되었다. 반면에 산도는 적색 LED 광에서 가장 높았다. 과실의 안토시아닌 함량에 있어서‘대왕’은 청색과 혼합 LED 광에서 유의적으로 증가한 반면, ‘설향’은 혼합 LED에서 증가하였다. 적색 LED는 유기산에 있어‘대왕’과‘설향’과실에 각각 말산과 옥살산의 함량을 증가시켰다. ‘대왕’ 과실의 페놀화합물 함량은 적색 LED와 대조구인 백열등이 다른 LED 광 처리보다 유의적으로 높았으나, ‘설향’ 과실은 대조구인 백열등에서 가장 높게 나타났다. 효과적인 생산량과 과실 품질을 고려해 볼 때, 겨울철 딸기 재배에 있어 보조광원으로 청색 LED 광이 유리할 것이다.

This study describes an efficient and stable droplet vitrification following cryopreservation of strawberry shoot tip (Fragaria × ananassa Duch.) accessions ‘Massey’ and ‘MDUS3816’. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 17.5% glycerol and 17.5% sucrose for 40 min and exposed to dehydration solution (B1) containing 50% glycerol and 50% sucrose for 40 min at 25oC. Subsequently, the explants were transferred onto droplets containing 2.5 μL PVS3 on sterilized aluminum foils (4 ㎝× 0.5 ㎝) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with 0.3M sucrose for 30 h + 0.5M sucrose for 16 h at 25oC. The cryopreserved shoots tips exhibited 57.8 % recovery rate by culturing in NH4NO3-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0㎎/L GA3, and 0.5 ㎎/L BA for 5 weeks and in MS medium supplemented with 0.5 ㎎/L GA3 for 8 weeks. Variation was not observed in both of ploidy analysis and morphological investigation on plantlets of two accessions cryopreserved under variable preculture conditions.

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of strawberry (Fragaria × ananassa Duch.) cvs. ‘Wonkyo3114’ and ‘Gurumi40’. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.5M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 20% glycerol and 20% sucrose for 40 min and exposed to dehydration solution (B5) containing 40% glycerol and 40% sucrose for 40 min at 25℃, Subsequently, the explants were transferred onto droplets containing 2.5 μL PVS3 on sterilized aluminum foils (4 ㎝ × 0.5 ㎝) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with MS + 0.3M sucrose for 40 h at 25℃. The cryopreserved shoots tips exhibited 55% regrowth rate by culturing in NH4NO3-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0㎎/L GA3, and 0.5 ㎎/L BA for 5 weeks and in MS medium supplemented with 0.5 ㎎/L GA3 for 8 weeks. This result shows that droplet-vitrification could be employed as a promising method for cryostorage of strawberry germplasm.