• 한국작물학회지
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• 제49권5호
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• pp.373-380
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• 2004

The production of sweet (su) and super sweet corns (sh2) has been economically feasible in Korea in recent years. Major factors limiting super sweet corn production are low germination and low seedling vigor. Since seed quality is closely related to seed maturity, the optimum harvest time for the seed production of sweet and super sweet corns was studied and the quality of seeds with varying maturities was investigated in 2001 and 2002 cropping seasons. The parents of the sweet corn seeds were Hybrid Early Sunglow and 'Golden Cross Bantam 70' and those of super sweet corn were Xtrasweet 82 and 'For­tune'. Seeds were harvested at 21, 28, 35, 42, 49, and 56 days after silking (DAS). As the seeds developed, seed weight of sweet corn increased and the seed moisture content decreased faster than that of super sweet corn. Germination rates of sweet corn seeds harvested 21 and 28 DAS at $25^{\circ}C$ and emergence rates in the cold soil test were significantly lower than those of seeds harvested after 42 DAS in both years. Although the germination rates of super sweet corn seeds with varying maturities showed similar patterns as sweet corn seeds at $25^{\circ}C$, the emergence rate of super sweet corn seeds in cold soil test continuously increased with seed maturity. This suggests that seed quality of super sweet corn should be tested in a cold soil test to estimate field emergence. As the seeds developed, leakage of total sugars and electrolytes from the both sweet and super sweet corn seeds decreased up to 42 or 49 DAS. The $\alpha-amylase$ activities of both sweet and super sweet corn seeds increased with seed maturity from 21 to 35 or 49 DAS depending on genotype and year. The optimum harvest time for the seed production of sweet corn was 42 DAS and 49 DAS for super sweet corn considering emergence rate and plumule dry weight in the cold soil test, leakage of sugars and electrolytes from the seeds, and $\alpha-amylase$ activity.

• 한국작물학회지
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• 제53권1호
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• pp.70-74
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• 2008

자운영 종자 생산을 위한 적정 수확시기를 결정하고자 개화 후 25일부터 5일 간격으로 40일까지 수확한 시험의 결과를 요약하면 아래와 같다. 1. 수확 시기별 자운영 종자 수량은 수확시기가 늦어질수록 증가하는 경향을 보였으며, 개화 후 35일이 가장 많았다. 2. 자운영 종자활력은 개화 후 35일 이후 수확한 것이 90%이상 높았으며 포장에서 자운영 지속재배를 위한 적정환원 시기는 개화 후 35일 이후였다. 3. 자운영 수확 후 발아율은 수확시기에 따른 차이가 인정되지 않았지만 저장기간이 길어질수록 늦게 수확한 것이 발아율이 높았다. 4. 발아율은 $10{\sim}40$일 침종에서 증가하였으며, 40일 이상 침종시 발아율이 급격하게 떨어지는 경향을 보였다. 5, 경실율도 개화 후 수학시기가 늦을수록 증가하는 경향을 보였다. 이상의 결과로 자운영 종자 수확을 위한 적정 수확시기는 개화 후 35일이 적당할 것으로 사료된다.

• 한국작물학회지
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• 제47권5호
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• pp.361-367
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• 2002

In order to determine the optimum harvest time for the seed production of inbreds and hybrids in silage corn, the ears of sib-pollinated 'KS5', 'KS7rhm', and 'Ga209' and cross-pollinated 'KS5' $\times$ 'KS6' (Suwon19), 'KS7 rhm' $\times$ 'KSl17' (Suwonok), and 'Ga209' $\times$ 'DB544'(Kwanganok) were harvested at the one-week intervals from 4 to 10 weeks after silking. The optimum harvest time for the seed production for 'KS5', 'KS5' $\times$ 'KS6', 'KS7 rhm', and 'KS7rhm' $\times$ 'KS117' was 7 weeks after silking considering both emergence rate and plumule growth in cold test. Although earlier harvested seeds showed similar germination rate as the seeds harvested at the optimum time at $25^{\circ}C$, their emergence rate were lower in cold test. Seed weight and $\alpha$-amylase activity of earlier harvested seeds were lower compared to those of seeds harvested at the optimum time, while leakage of total sugars and electrolytes were higher. However, the later harvested seeds showed lower germination rates at $25^{\circ}C$ and emergence rates in cold test probably due to the lower $\alpha$-amylase activity although they showed increased seed weight and reduced leakage of total sugars and electrolytes. In contrast, the emergence rate of 'Ga209' and 'Ga209' $\times$ 'DB544' in cold test increased up to 10 weeks after silking probably due to the increased seed weight and $\alpha$-amylase activity and reduced sugar and electrolyte leakages during the germination. The cross-pollinated F$_1$ hybrid seeds showed higher germination and emergence rates at $25^{\circ}C$ and in cold test, and higher plumule growth and $\alpha$-amylase activity compared to those of sib-pollinated inbreds.

• 한국작물학회지
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• 제33권2호
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• pp.126-133
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• 1988

우리나라에서 호밀을 채종 목적으로 재배할 때 여름 장마로 인한 호밀 성숙후기 이후에 발생하는 종자 품질저하를 최소화할 수 있는 조기수확한계기를 구명하고자 팔당 호밀(재래종)을 공시하여 출수후 25일부터 55일까지 5일 간격으로 수확기를 달리하고 종실발육 수량 및 종자활력에 관한 시험조사를 1984년 및 1986년에 영남대학교 실험농장에서 실시하였던 바 그 결과를 요약하면 다음과 같다. 1. 수확기별 천립중변화는 출수후 50일까지는 수확 지연에 따라 직선적으로 증가하나 그 이후는 연차에 따라 일정하지 않았다. 종실수분함량은 수확이 늦었을 때 반대로 감소하였다. 2. 종실의 길이는 출수후 30일까지 빠르게 그리고 그 이후는 완만하게 신장되었고, 두께와 폭은 출수후 50일까지 완만하게 발육되었다. 3. 수확기가 늦어짐에 따라 수량이 높아지는 영향은 뚜렷하나 출확기 40일과 45일 수확에서 차이가 크다. 4. 2$0^{\circ}C$ 항온에서 종자발아율은 출수후 25일 수확구를 제외하면 종자성숙에 따라 발아율의 차이가 없으나, 1$0^{\circ}C$, 3$0^{\circ}C$에서는 출수후 35일 이전 수확에서 발아율이 낮았다. 실온에서 pot 에 파종한 경우 발아율은 2$0^{\circ}C$ 항온에서와 유사하였다. 5. pot에서 초장은 종자성숙이 진전될수록 긴 경향이나 출수후 45일 이후 수확 종자간에는 차이가 없고 유묘의 건물중은 출수후 50일까지 종자성숙기간이 길수록 높았다. 6. 항온에서 종실의 성숙일수와 발아율간의 상관은 저온(1$0^{\circ}C$) 및 발아초기(치상후 4일)에서만 정의 상관이 있었다. pot 에서는 종실의 성숙일수와 초장, 건물중 그리고 천립중간에는 유의한 정의 상관을 보였다. 7. 포장에서 월동후 유식물수 비율은 57~67%로 출수후 30일~50일에 수확한 종실간의 차이가 없으나 생육초기의 초장은 출수후 35일 이전 수확한 종실의 경우는 작았다. 출수기는 출수후 40일 수확한 종실은 출수기가 늦지 않으며 간장은 종자 성숙정도 차이가 인정되지 않았다. 8. 채종목적인 호밀 재배에서 우기를 회피하여 종자 수량감소 최소화할 수 있는 수확기는 출수후 45 일 (개화후 38일)경 이라고 본다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.45-45
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• 2018

We had already reported the successful germination for green pods of purple lady's slipper orchid (Cypripedium macranthos Sw.). The green pod methods is to take immature seeds in green capsules, sterilize the capsule, and take out the sterile seeds. This method, however, needs very critical time of harvest. The critical time of seed harvest changes depending upon the species, condition of the specimen, and climatic influence, and the right time lies between 5 and 12 weeks after fertilization. In this study, the mature seeds were collected after 120-130 days with hand-polination of lady's slipper orchids. Mature seeds are usually dormant and it has to be overcome, either with hormone or storing the seeds near freezing for two or three months to break dormancy. The seeds were first surface sterilized with 70% ethanol and then transferred 1% NaOCl for 10-15 minutes, followed by rinses 3 times with sterilized distilled water. The cypripedium seeds consists of an embryo within a seed coat known as a testa. The testa is water repellent and the seed has a large air space between the embryo and testa so the seed tends to float on water. We had resolved the problems with vacuum pump to soak water into the testa before sterilization. The seeds were placed on liquid or agar solidified germination media. Cultures were incubated at $24{\pm}1^{\circ}C$ in dark. The seeds were germinated in 6-8 weeks in liquid suspension culture (germination percentage over 18%); however, the seeds on agar solidified media took more than 5 months to germinate and the germination percentage less than 5%. The most effective media for liquid culture was 1/4 strength Murashige and Skoog (MS) medium with 50 ml/l coconut water ($4brix^{\circ}$) at pH 5.8.

• 한국작물학회지
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• 제47권4호
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• pp.311-318
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• 2002

Planting date of soybeans [Glycine max (L.) Merr.] is one of production components in cultural systems. The objective of the current study was to identify the components of soybean production and cultural practices encompassing planting dates and cultivars that respond to dry matter accumulation, harvest index and yield components. Three determinate soybean cultivars were planted on May 13 (early), June 3 (mid), and June 24 (late). Planting density was 60$\times$15cm with 2 seeds (222,000 plants per ha). Soybean plants were sampled every 10 days interval from the growth stages of V5 to R8 and separated into leaves including petioles, stems, pods, and seeds. Dry matter accumulations, harvest indices, and yield components were measured. Early planting had taken 55 days from VE to R2 and late planting taken 39 days indicating reduced vegetative growth. Early planting showed higher leaf, stem, pod and seed dry weights than late planting. However, late planting appeared to be higher harvest index and harvesting rate. Vegetative mass including leaf and stem increased to a maximum around R4/R5 and total dry weight increased to a maximum around R5/R6 and then declined slightly at R8. The highest seed yield was obtained with mid planting and no difference was found between early and late plantings. Cultivar differences were found among planting dates on growth characteristics and yield components. The results of this experiment indicated that soybean yield in relation to planting dates examined was mainly associated with harvest index and harvesting rate, and planting date of cultivars would be considered soybean plants to reach the growth stage of R4/R5 after mid August for adequate seed yield.

• 한국작물학회지
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• 제59권4호
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• pp.406-412
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• 2014

The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

• 한국작물학회지
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• 제33권2호
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• pp.134-137
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• 1988

인삼 종자의 발육시기별 종자 및 배유의 크기, 사포닌, 유리당 그리고 지방산의 함량을 조사하였던바 그 결과는 다음과 같다. 1. 종자의 크기(길이, 폭, 두께) 생장은 개화후 35 일경에, 배유의 크기 생장은 개화후 50일경에 완료되었으나 장육을 제거하지 않은 종자의 무게는 개화후 65일까지 감소되었다. 2. 총사포닌 및 ginsenosides의 함량은 개화후 일수가 경과할수록 감소되었다. 3. Glucose, maltose 및 fructose의 함량은 개화후 일수가 경과할수록 감소되었으나 sucrose 함량은 경과일수에 따라 증가되었다. 4 Palmitic 산의 함량은 개화후 일수가 경과함에 따라 감소경향이었으나 oleic, linoleic 및 stearic산은 경과일수에 따라 증가되었다.

• Journal of Forest and Environmental Science
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• 제35권2호
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• pp.69-77
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• 2019

Pterocarpus erinaceus is a multipurpose tree species indigenous to semi-arid and Guinean-savanna woodlands of Africa. Natural regeneration on the savanna is being hampered by higher fire frequencies and other land use changes. Simultaneously, demand for timber from the species on the international market is on the rise, raising conservation concerns. To ensure sustainability, good quality seeds, sources of which have not received much research focus, are needed for afforestation. This study investigated how seed quality, germinability and initial seedling growth of P. erinaceus might be influenced by land-use type, mother tree size as well as source and timing of fruit harvest, using both correlational and experimental approaches. The results showed that up to 94.6% of all harvested fruits contained seeds, with no differences found between fruits harvested from cultivated and non-cultivated lands. Percentage of (sound) unblemished seeds was found to be higher for fruits harvested early March (47.3%) than fruits from late April (39.5%). Percentage sound seeds was 41.4% for dispersed fruits (i.e. detached fruits picked from under mother trees) which was not found to differ from undispersed fruits (i.e. fruits harvested while still attached to mother trees) at 45.5%. Also, the influence of fruit harvest time was not found to be different for dispersed and undispersed fruits. Correlations between seed set (proportion of fruits containing seeds) and mother tree size (both tree height and DBH) were found to be very low and non-significant for both dispersed and undispersed fruits. Across mother trees, mean emergence percent was 79.7%, and mean seedling height at three weeks following emergence was 5.32 cm. Both emergence percentage and seedling height were not found to differ among mother trees, but seeds from dispersed fruits had a higher emergence percent (85%) than seeds from undispersed fruits (74%). Implications of findings are discussed.

• 한국작물학회지
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• 제65권4호
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• pp.274-283
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• 2020

본 연구는 조평과 조운의 벼 출수 후 적산온도와 검정온도에 따른 수발아 발생 정도를 조사하고, RNA-sequencing 방법을 사용하여 수발아 발생 원인을 찾았다. 품종간 수발아성에 관여하는 생리적, 유전학적 요인을 구명하고자 수행하였으며 분석한 결과는 다음과 같다. 1. 출수 후 적산온도가 높아질수록, 검정온도가 높아질수록 수발아 처리시 수발아율이 높았고, 조운벼가 내수발아성이 강하고, 조평벼가 수발아성이 높은것으로 나타났다. 2. 수발아성이 높은 조평벼를 대상으로 한 RNA-sequencing 결과 ABA 생합성에 관여하는 OsNCEDs의 발현이 감소하고, ABA 분해에 관여하는 OsCYP707As의 발현이 증가하였다. 3. 조평과 조운의 OsNCEDs와 OsCYPY707As의 Quantitation Real-Time PCR 결과 조평보다 조운에서 OsNCEDs의 발현이 높게 나타나 수발성과 상관관계를 보였으나, OsCYP707As는 수발아성과 상관관계를 보이지 않았다. 4. 조운벼는 등숙기간중 종실내 ABA함량이 조평보다 높으며 수발아 처리시 남아있는 ABA함량이 높아 내수발아성이 상대적으로 강하게 나타났다.