초록 ▼

○ 연구결과
1. 신품종 매향 딸기의 산업화를 재배 기술 확립
- 매향은 기존 일본 육성 재배 품종에 비하여 수량이 높고 과실 품질이 우수하여 경쟁력이 높은 품종으로 확인되었으며 국내에서 대체품종으로 유망함
- 매향의 수량은 기존 품종에 비하여 다소 낮으나 가격이 높은 이듬해 2월까지 수량은 차이가 없어 대체 품종으로의 가능성이 확인됨
- 초촉성 재배에서 근관부 직경이 4mm이상의 묘에서 수량(총수량, 상품과 수량)이 우수함
- 주간 재식거리는 15cm로 밀식 재배에서 수량이 우수함
- 고온기 차광재

○ 연구결과
1. 신품종 매향 딸기의 산업화를 재배 기술 확립
- 매향은 기존 일본 육성 재배 품종에 비하여 수량이 높고 과실 품질이 우수하여 경쟁력이 높은 품종으로 확인되었으며 국내에서 대체품종으로 유망함
- 매향의 수량은 기존 품종에 비하여 다소 낮으나 가격이 높은 이듬해 2월까지 수량은 차이가 없어 대체 품종으로의 가능성이 확인됨
- 초촉성 재배에서 근관부 직경이 4mm이상의 묘에서 수량(총수량, 상품과 수량)이 우수함
- 주간 재식거리는 15cm로 밀식 재배에서 수량이 우수함
- 고온기 차광재배는 숙기촉진을 다소 지연시킬 수 있으나 과실 품질이 떨어지는 단점이확인됨
2) 딸기 냉각 및 이산화탄소 처리에 따른 생리적 반응 구명 및 수확 후 처리 기술 실용화
- 수확한 딸기의 냉각, 이산화탕소 처리는 매우 유용한 수확 후 처리기술로 수확한 과실의 경도를 증진시킴은 물론 부패를 억제시킴
- 신품종 매향은 우수한 경도증진 반응을 보임. 레드펄을 비롯한 기타의 품종은 매향보다 우수하지 않았으나 아끼히메보다 우수하였음
- 이산화탄소 처리에 EK른 경도 증진은 세포벽의 구조적 변화와 관련이 적으나 세포의 미세 환경(세포벽 pH, 결합칼슘의 변화)에 영향을 주어 발생하는 것으로 추정됨
- 적정 CO2처리는 15%이상의 농도에 노출된 시간이 3시간 이상일 때 경도 증진 반응이 명확함
3) 딸기 품종식별 기술 개발
- 딸기 DNA 분리에서 정제가 되지 않아 선명한 DNA 분리 결과를 얻지 못하는 기술적 문제점을 해결하기 위한 따리 DNA 추출 정제 기술 확립
- 국내에서 재배되고 있는 주 품종과 보유 품종 10종을 대상으로 178개의 10merprimer를 검토하여 이들 10품종의 품종 식별에 활용될 수 있는 5개의 primer을 선별하고 검증함

Abstract ▼

Ⅰ. Title
Identification of strawberry cultivar through molecular marker, and development of cultural practices and postharvest management system for strawberries.
Ⅱ. Objectives and importance
Strawberry industry in Korea has been increased, resulting in the increase of farmer's income. Most

Ⅰ. Title
Identification of strawberry cultivar through molecular marker, and development of cultural practices and postharvest management system for strawberries.
Ⅱ. Objectives and importance
Strawberry industry in Korea has been increased, resulting in the increase of farmer's income. Most strawberry cultivars grown in Korea were originated from Japan and major cultivars included ‘Red Pearl’ and ‘Akihime’. Commercial production of strawberries developed from Korea was extremely limited because of unstable quality. This situation resulted in the poor development of strawberry industry in Korea. Due to the involvement of Korean government to UPOV, royalty to Japanese cultivars has been a serious issue and the export of fresh strawberry to Japan is almost completely interrupted recently.
‘Maehyang’, newly released Korean cultivar, developed from Nonsan Strawberry Experiment Station has a strong potential for commercialization because this cultivar has properties such as high sugar content and yield, excellent flavors. However, the optimum cultural practices and/or key points in ‘Maehyang’ cultivation has not been clearly found. It is strongly necessary to figure out the cultural practice to overcome the problems which were found in pilot cultivation. And understanding postharvest behavior of ‘Maehyang’ is also important to develop a postharvest management system.
Identification of strawberry cultivars has difficulties due to the complexity of genetic background and vagueness of phenotypes. Problems due to poor identification system of strawberry cultivars are often occurred, and, thus, the development of an objective and precise technology is required to prevent the problems associated with nursery plants.
In this research, we have been focused 1) to develop a cultural practices based on understanding physiological and ecological properties, 2) to find out the mechanism associated with firmness increase by CO₂ treatment, 3) to develop a postharvest technique to keep freshness during marketing of strawberries including ‘Maehyang’, finally 4) to develop a molecular marker(s) for the identification of strawberry cultivars grown in Korea. Through a systemic research, we tried to suggest a commercialization model of new strawberry cultivar.
Ⅲ. Content and scope
1. Development of cultural practices of new strawberry, ‘Maehyang’
1) Understanding physiological and ecological properties of ‘Maehyang’ strawberry
The floral induction in Nonsan area occurred near on September 20 and there was 1-2 day difference between cultivars but the growth rate of flower bud clearly differed between cultivars. ‘Akihime’ was the most rapid rate of flower bud development and followed by ‘Maehyang’, ‘Red Pearl’ and ‘Sachinoka’. In forcing culture of ‘Maehyang’, the time of second flower bud differentiation was near on October 10, thus, this was the right time to start protection from cold weather.
Early preparation of mother plants has advantages to get healthy daughter plants because the root growth of ‘Maehyang’ was relatively slow. The amount of runner development per plant was lower than that of ‘Red Pearl’ but similar to that of ‘Akihime’.
The requirement of cold treatment to overcome dormancy in ‘Maehyang’ was approximately 150 to 200 hours. It was a little longer than ‘Akihime’ cultivar. ‘Maehyang’ is susceptible to anthracnose, especially in nursery stage.
To get a healthy nursery plant, it is required to produce daughter plant under protective house. ‘Maehyang’ showed a relatively high resistance against powdery mildew. As pest, spider mites and aphids occurred in growing season.
The induction of abnormal fruit development in ‘Maehyang’ is relatively lower than other cultivars. However, when plants were exposed to freezing temperature at cold season, the occurrence of abnormal fruit rapidly increased.
Thus, abnormal fruit were probably produced in the second flower cluster. It is strongly required to protect the plant from freezing in coldest season.
2) Cultural practices for high yield of ‘Maehyang’ strawberry
The yield of ‘Maehyang’ per unit area was higher in early forcing culture than semi-forcing culture. In semi-forcing culture, the peak of yield occurred on April when fruit quality was dropped in general. The early forcing culture showed the highest profits due to the quality and yield increase but it was required to induce flower differentiation by artificial chilling treatment.
Daughter plants with crown diameter of 5∼6mm showed the high yield in early season and the optimum space for planting was 15cm. The total yield of ‘Maehyang’ was a little lower than that of ‘Akihime’ but higher than that of ‘Red Pearl’. Decrease of fruit quality was observed in fruit produced at high temperature season like other cultivars. However, the content of soluble solids and acidity maintained at relatively higher level even in high temperature season. Thus fruit showed typical flavor even in high temperature season.
There was a decrease of fruit firmness at high temperature season. This problem can be overcome by early harvest. ‘Maehyang’ was appeared to be suitable for long term cultivation.
In ‘Maehyang’, no significant different in sugar content was found between fruit maturity at harvest from 70∼90% surface coloration. Fruit firmness of full ripe fruit was severely decreased. It is required to shorten the harvest interval at high temperature season.
No clear effect of stebia and salt application on solid increase was found and also other mineral fertilizers such as Buksal, potassium slicate and chitosan showed little effect.
Shading treatment at high temperature season reduced the over coloration of fruit. However, because shading reduced the fruit quality, it is recommended not to apply shading covering by March, 35% shading by April 20, and 55% shading after May 5.
2. Postharvest management and understanding mechanism of firmness increase by CO₂ treatment
1) Quality comparison between harvest maturity and cultivars, and physiological response to high CO₂ treatment There were differences in fruit quality such as firmness between farming areas, probably resulting from the difference of cultural practice. Full ripe fruit (100% colored) were not suitable for fresh market because of poor shipping quality. There was an increase of soluble solids and decrease of acidity when fruit approached to full ripe stage, resulting in the increase of sugar/acid ratio.
The level of soluble solids was higher in ‘Maehyang’ at similar stage of maturity and acid was lower in ‘Akihime’.
The amount of soluble solids was highest in fruit produced on January and the later the harvest season, the lower the soluble solid levels regardless of cultivars. The ranges of solid decrease was highest in ‘Akihime’ and lowest in ‘Maehyang’. Fruit firmness increase by high CO₂ treatment was confirmed in all cultivars expect ‘Akihime’.
Acid increase at late harvest season in ‘Maehyang’ was mainly due to the increase of malic acid, however, in ‘Akihime’, malic acid showed similar tendency to ‘Maehyang’ but citric acid also decreased. No clear change of internal fruit quality was found by CO₂ treatment. Also, the composition of soluble sugars did not affected by high CO₂ treatment. The contents of phenolics and ascorbic acid did not affected.
2) Anatomical changes by CO₂ treatment in strawberry fruit
It seemed that epidermal cells was probably shrunken during high CO₂ and cooling treatment. Cells at torn surface of fruit showed relatively sound appearance in CO₂ treated fruits. This tendency was more stronger in ‘Maehyang’ than ‘Akihime’.
3) Effect of high CO₂ treatment on the changes of cell wall and wall hydrolases
Alcohol insoluble solid(AIS) content was higher in ‘Maehyan’g than ‘Akihime’.
‘Akihime’ contained higher amount of water soluble pectins but Maehyang had more CDTA soluble pectins. CO₂ treatment seemed to reduce the increase of water soluble pectins in senescent fruit. CDTA pectins seemed to be increased by CO₂ treatment. Thus, the composition of pectins was affected by CO₂ treatment, resulting in the firmness increase in part. Wall hydrolases, β -galactosidase, activity was reduced by CO₂ treatment. This probably indicated that postharvest treatment of CO₂ seemed to be associated with fruit firmness through decreasing wall hydrolase activity and pectin changes in part. However, there was no clear evidence of structural changes of soluble pectins regardless of pectin species.
4) Changes of micro-environment in apoplast of fruit by CO₂ treatment
The CO₂ content of inside fruit significantly increased by CO₂ treatment but O₂ level did not affected. No detectable ethylene was found in both treatments.
The pH of intercellular space increased along with the increase of maturity.
Even no statistical difference was found, there was a tendency of intercellular pH increase by CO₂ treatment. Calcium content bound to AIS was also slightly increased by CO₂ treatment.
3. Postharvest application of CO₂ at commercial level.
Postharvest application of CO₂ is recommended to fruit for long term transport such as export. In domestic market, CO₂ treatment is not recommended except when it was necessary to store fruit for 3-4 days to meet the high market demand.
4. Identification of strawberry cultivars through molecular marker
Many strawberry cultivars of Korea have mixed, often unknown, genetic pedigrees. A study has been conducted to seek for molecular markers to distinguish 10 leading cultivars of Korea and Japan that have been dominated in markets for the last 10 years. This study should help breeders to chase the pedigree of characters or varieties. To find out molecular markers to detect differences in genetic make-ups of 10 varieties, total 179 primers of 10 nucleotides were examined from polymorphic DNA products under a certain PCR condition with DNA extracted from petals or leaves. Five primers were selected to reveal polymorphic DNA products among 10 varieties, ‘Toyonoka’, ‘Red Pearl’, ‘Akihime’, ‘Tochiotome’, ‘Sachinoka’, ‘Nohyo’, ‘Askabara’, ‘Suhong’.
From this study, we examined and established a set of 5 primers, RAPD-PCR condition, and DNA extraction method for the generation of highly reproducible PCR products. Since these conditions can molecularly identify relatively related 10 varieties that have been cultivated in Korea and Japan, our data should be informative to identify other strawberry varieties of different geographic and genetic origin.
Ⅳ. Suggestions
1. Expansion of ‘Maehyang’ cultivation
This study revealed a strong potential of ‘Maehyang’ for commercial cultivation. It is expected that the cultivation plan of ‘Maehyang’ in 2006 is already occupied approximately 9% of total strawberry cultivation area. It is also confirmed that ‘Maehyang’ has a potential to export to Japan as well as other Asian countries. To establish the stable production system of ‘Maehyang’ strawberry, it is also required to release the improved cultural practice to farmers and related personnels.
2. Postharvest system for strawberry industry.
The importance of postharvest procedures such as cooling, CO₂ treatment, and establishment of cold chains was confirmed to farmers and managers of packing houses. This will contribute to the increase of market quality of fresh strawberries. Especially, CO₂ treatment is necessary to keep freshness of fruit for export. Also, manuals for postharvest treatment is required to apply standard procedures.

목차 Contents

• 제출문 ... 1
• 요약문 ... 3
• SUMMARY ... 12
• CONTENTS ... 19
• 목차 ... 22
• 제1장 서언 ... 25
• 제2장 국내 육성 딸기 신품종 ‘매향’의 수출용 재배기술 확립 ... 27
• 제1절 서언 ... 27
• 제2절 재료 및 방법 ... 28
• 1. ‘매향’의 화아분화 특성 조사 ... 28
• 2. ‘매향’ 육묘기 자묘 발생 특성 ... 29
• 3. ‘매향’의 휴면 특성 ... 30
• 4. 병해충 저항성 ... 30
• 5. 작형과 재배방법에 따른 수량성 비교 ... 32
• 6. 품종간 수량성 및 품질 비교 ... 33
• 7. 숙도별 과실의 품질변화 ... 33
• 8. 약제처리에 의한 과실품질 향상 ... 34
• 9. 차광처리에 의한 과실품질 향상 ... 34
• 10. 재배력 모델 설정 ... 34
• 제3절 결과 및 고찰 ... 35
• 1. ‘매향’ 품종의 생리ㆍ생태적 특성 구명 ... 35
• 가. ‘매향’의 화아분화 특성 ... 35
• 나. ‘매향’ 육묘기 자묘 발생 특성 ... 36
• 다. ‘매향’의 휴면 특성 ... 38
• 라. 병해충 저항성 ... 40
• 마. 온도 적응성 ... 41
• 2. ‘매향’의 재배기술 정립 ... 42
• 가. 작형에 따른 수량성 비교 ... 42
• 나. 재배방법에 따른 수량성 비교 ... 43
• 다. 품종간 수량성 및 품질 비교 ... 45
• 1) 생산시기별 품종간 수량 및 품질 비교 ... 45
• 2) 숙도별 과실 품질 변화 ... 49
• 3) 약제처리에 의한 과실품질 향상 ... 52
• 4) 차광처리에 의한 과실품질 향상 ... 54
• 5) 재배력 모델 설정 ... 59
• 6) 세부 작업일정 ... 62
• 제3장 딸기의 CO2 처리에 따른 경도 증가 반응 해석 및 수확 후 처리 방안 ... 64
• 제1절 서언 ... 64
• 제2절 재료 및 방법 ... 65
• 1. 생육시기별 품종별 과실 품질 및 CO2 처리반응 비교 ... 65
• 2. CO2처리에 따른 해부학적 및 미세환경의 변화 ... 70
• 3. 딸기의 실용적 CO2 처리기술 ... 70
• 제3절 결과 및 고찰 ... 71
• I. 딸기 품종과 숙도에 따른 과실 품질 및 CO2 처리 반응 ... 71
• 1. 품종과 숙도에 따른 딸기 과실의 품질 비교 ... 71
• 2. 주요 재배 딸기 품종의 수확 시기에 따른 과실의 품질과 CO2 처리 반응 ... 75
• 3. CO2 처리가 ‘매향’과 ‘아끼히메’ 딸기의 품질에 미치는 영향 ... 82
• 4. CO2 처리가 딸기 과실의 해부학적 변화에 미치는 영향 ... 92
• 5. CO2 처리가 딸기 과실의 세포벽 조성과 세포벽 가수분해에 미치는 영향 ... 95
• 6. CO2 처리 전후의 경도증진 요인 분석 ... 101
• 가. CO2처리에 따른 과실 조직 내부 공기조성 변화 ... 101
• 나. 세포벽 pH 변화 ... 101
• 다. CO2처리에 따른 양이온 변화 ... 103
• 7. CO2 처리가 생리적 반응이 다른 ‘매향’과 ‘아끼히메’의 생리적 변화에 미치는 영향 ... 104
• 가. CO2 처리반응이 다른 두 품종의 생리적 차이 비교 ... 104
• 나. ‘매향’과 ‘아끼히메’ 품종의 CO2처리에 따른 세포벽 성분의 구조적 변화 ... 109
• II. 실용적 CO2 처리 방안 ... 115
• 제4장 ‘매향’을 포함한 딸기 품종의 분자학적 선별기술 개발 ... 121
• 제1절 서언 ... 121
• 제2절 재료 및 방법 ... 122
• 1. DNA 추출 ... 122
• 2. RAPD를 위한 PCR 조건 ... 122
• 가. RAPD에 사용한 primers ... 122
• 나. RAPD를 통한 품종식별 ... 122
• 제3절 결과 및 고찰 ... 123
• 1. Genomic DNA 추출 및 정제 기술 확립 ... 123
• 가. 딸기 DNA 추출 및 정제 ... 123
• 나. 재현성 있는 PCR 조건 확립 ... 124
• 다. 우수 primer 선발 ... 125
• 2. 표준 primers 선발을 위한 RAPD 결과 ... 128
• 가. Primer OPB5를 통한 딸기 품종간 polymorphism 비교 ... 129
• 나. Primer OPJ4를 통한 딸기 품종간 polymorphism 비교 ... 131
• 다. Primer OPV2를 통한 딸기 품종간 polymorphism 비교 ... 132
• 라. Primer OPW3를 통한 딸기 품종간 polymorphism 비교 ... 133
• 마. Primer OPX3를 통한 딸기 품종간 polymorphism 비교 ... 134
• 3. 결론 ... 135
• 제5장 종합고찰 ... 136
• 인용문헌 ... 141
• 끝페이지 ... 146