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.

This study was investigated to develop mass evaluation system for the contents of crude protein, oil and fatty acid in soybean germplasm using NIRS. NIRS equations were created with 345 soybeans, multiple correlation coefficients of crude protein, oil, palmitic, stearic, oleic, linoleic and linolenic acid between data obtained from NIRS and quantitative analysis were 0.983, 0.969, 0.592, 0.514, 0.978, 0.961 and 0.957, respectively. Equation statistics indicated that contents of crude protein, oil and unsaturated fatty acid except palmitic and stearic acid in soybean seed were suitable for determination by NIRS. Those NIRS equations were applied to examine crude protein, oil and unsaturated fatty acid of 854 soybean landraces from Korea. The average contents and ranges of crude protein and oil were 39.2% with a range of 33.7-47.0% and 15.0% with a range of 9.8-20.3%, individually. In addition, those of oleic, linoleic and linolenic acid were 21.4% with a range of 12.1-30.2%, 55.6% with a 47.8-62.3% and 8.1% with a range of 5.9-10.7% respectively. We conducted quantitative analysis to reconfirm with IT154552 (45.1%) and IT023955(46.9%) above 45% of crude protein, the results were similar from NIRS (45.2%, 47.0%). NIRS data for protein from this study made no difference with lab data, which would be useful for mass evaluation. There was negative correlation (-0.203) between crude protein and oil, positive correlation (0.379) between crude oil and oleic acid, and significantly negative correlation (-0.879) between oleic and linoleic acid.

본 연구는 한국, 중국, 엘살바도르 강낭콩 유전자원을 대상으로 농업특성을 조사하고, 분자마커를 이용하여 유전적 다양성을 분석하였으며 결과는 다음과 같다. 첫째, 개화일수 전체 평균은 61일, 범위는 41일에서 83일, 생육일수는 평균 104일, 범위는 86일에서 143일 사이였다. 엘살바도르 자원의 평균 생육일수는 97일로 한국, 중국의 104일과 103일보다 6∼7일 빨랐다. 둘째, 협장은 전체 평균 10.9 cm, 범위는 4.2∼19.5cm, 중국 자원의 평균 협장은 12.7 cm로 가장 길고 범위도 7.0∼19.5 cm로 넓었다. 협폭의 전체 평균은 11.7 mm, 범위는 5.6∼27.5 mm, 중국 자원의 평균 협폭은 12.8 mm, 범위는 6.7∼27.5 mm로 3개국 중 가장 넓었다. 셋째, 100립중의 전체 평균은 40.9 g, 범위는 18.1∼69.3 g, 한국과 중국 자원의 평균 100립중은 각각 44.3 g, 42.7 g으로 유사하였으나 엘살바도르 자원의 평균 100립중은 26.3 g으로 매우 작았으며 분포범위도 18.5∼32.1 g으로 좁았다. 넷째, 신육형은 유한형이며 직립형 자원이 35.7%, 무한형이며 덩굴성인 자원이 46.4%였으며, 신육형이 중간형이고 덩굴성 자원이 16.1%로 나타났다. 한국 자원은 유한형과 무한형의 비율이 유사하였으며, 중국 자원의 신육형은 무한형이며, 덩굴성 자원이 60.5%, 엘살바도르는 중간형이며, 덩굴성 자원이 90.1%로 대부분을 차지하였다. 다섯째, 종피색은 전체적으로 적색자원이 평균 44.5%로 가장 많았으며, 특히 엘살바도르는 적색자원이 83.3%로 대부분이었고, 종자모양은 신장형이 평균 30.4%로 가장 많았으나, 한국자원은 계란형(36.6%), 중국자원은 신장형(55.3%), 엘살바도르는 입방형(79.2%)이 많아 국가별 차이를 보였다. 여섯째, 한국 자원 292점, 중국 자원 72점, 엘살바도르 자원 71점 등 435점을 대상으로 8개의 SSR 마커를 이용한 유전적 다양성 분석을 수행하였으며, 그 결과 총 92개의 allele가 확인되었고, gene diversity 와 PIC로 볼 때 중국 자원이 각각 0.73, 0.69로 가장 높았으며, 엘살바도르 자원은 0.48과 0.45로 가장 낮은 것으로 나타났다.