• 한국작물학회지
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• 제53권4호
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• pp.421-426
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• 2008

Freshly harvested seed of Chinese milk vetch (Astragalus sinicus L.; CMV) was strongly dormant because of hardseedness. Seeds of freshly harvested germinated only 8% while clipping the seed coat completely overcome the innate dormancy, which indicates inhibition of germination of the seed is mainly due to seed coat (87%). The dormant (intact) hard seeds did not imbibe water whereas the non-dormant (clipped) seeds took up rapidly. In natural environment condition, the hard seed coat dormancy was broken only after 5 months after seed harvest. To break such a strong seed coat dormancy, the chemical and heat treatments were effective. Concentrated sulfuric acid was more effective than dry heat and hot water treatments. Hot water treatment improved germination but the germination percentage was less than 41%. Treatments increased germination due to its effect on the seed coat integrity. A scanning electron microscope reveled that disruption of seed coat layers and subsequent development of numerous crack in the hilum region of the seed and on the seed coat surface of concentrated sulfuric acid treatment and formation of cracks in the dry heat treatments, respectively, were observed in the seed coat surface, which served as water entry points.

• 한국작물학회지
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• 제47권2호
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• pp.80-84
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• 2002

In spite of simple and cheap cultivation method, water broadcast-seeded rice demonstrates uneven and unstable seedling establishment per unit land area and requires more herbicide and labor-input for weed control. Three experiments were conducted in a phytotron at 18$^{\circ}C$ to evaluate the adaptability of seed-mat mulching cultivation technologies in water seeded rice for the uniform seedling establishment and the inhibition of weed occurrence without herbicide application. Five different kinds of mat with different mesh sizes and fabric properties were tested. The emergence of rice was the highest in Lawn-mat treatment, being comparable with the control, in which seeds were sown without mat. The Lawn-mat also exhibited the lowest mat tension. Mat tension may influence the emergence of rice. And once it was soaked in water, it didn't maintain its original shape any more. The emergence rate of rice was the lowest in Safer-mat treatment. In Lawn-mat treatment, which was the most effective for rice emergence in the first study, the differences of emergence and seedling establishment of rice depending on the seeding position (upper, beneath, and between mats) treatments were negligible, while they were higher in dry seeds than in pre-germinated seeds treatment. The emergence as affected by the kinds of mat also showed the same trend when tested using barnyard grass. Depending on the kinds of mat, the inhibition effect of weeds was the greatest in Safer-mat and the poorest in Lawn-mat. These results strongly suggest the possibility that the uniform seedling establishment and weed management without chemical could be achieved simultaneously by seed-mat mulching through the combination of effective mat for the emergence of rice and another efficient mat for the inhibition of weed occurrence. This possibility was also tested in the field.

• 한국응용곤충학회지
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• 제1권
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• pp.42-46
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• 1962

(1) 위조독소(Fusaric acid)를 생성하는 참깨, 시들음병균(Fusarium oxysporun f. vasinfectum)의 배양여액이 참깨, 밀, 목화, 벼 등의 종자의 발아에 미치는 영향을 구명하기 위하여 본시험에 착수하였다. (2) 공시균의 10종의 계통의 배양여액을 첨가한 발아상에 있어서의 참깨, 목화, 밀, 벼 등의 종자의 발아상태를 조사한 결과 공시균의 몇 가지 계통의 배양여액은 이들 작물종자의 발아에 뚜렷한 경향을 주지 않지만 대부분의 계통의 배양여액은 참깨, 목화, 밀, 벼 등의 종자발아를 완전히 조지하거나 혹은 발아지연 또는발아율의 저하를 초래한다는 것을 알았다. a. 공시균의 10종의 계통중 201호균의 배양여액은 참깨, 목화, 밀, 벼 등의 종자발아를 거의 완전히 저지하고 있으며 발아를 유제하는 독성에 있어서 작물간차이는 볼 수 없었으나 이 밖의 281, 321호균 등의 배양여액은 참깨, 목화. 밀, 벼 등 종자의 발아를 억제하는 독성에 있어서 작물간 차이를 볼 수 있었다. b. Fusarium oxysporum f. vasinfectum의 첩양여액이 종자발아를 억제하는 독성에 대하여 참깨가 가장 감수성이 강하고 벼는 감수성이 가장 약하며 밀, 목화 등의 감수성은 참깨와 혀의 그것의 중간에 속한다. (3) Fusarium oxysporum f. vasinfectum 여러 가지 계통균이 혼재하는 토양에서는 밀, 벼 등 비기주작물도 이 균이 토양중에 생성하는 Fusaric acid에 의하여 종자발아나 발아후의 생육이 저해될 가능성이 있다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.25-25
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• 2014

Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

• 현장농수산연구지
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• 제13권1호
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• pp.27-33
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• 2011

코팅소재별 벼 종자의 발아 및 입묘 특성을 구명하기 위하여 무처리, 규산코팅, 철분코팅, 규산복토 처리에서 유묘의 입모율, 경시적 입묘양상의 변화, 초장, 엽수, 생체중의 특성을 조사결과를 요약하면 다음과 같다. 1. 입모율은 무처리 95% 규산코팅 및 규산복토 92%, 철분코팅 77%로 각가 나타나 무처리에서 가장 높게 나타났지만 일반적으로 각종 제한요인(새 피해, 건조, 부묘현상 등)이 많은 포장조건에서는 무처리 조건이 상반된 결과가 나타나고 있으며 규산코팅 또는 복토조건에서 철분코팅보다 높은 입묘율을 보였다. 2. 벼 유묘의 초장에서는 무처리 11.4cm 규산코팅 10.8cm, 규산복토 8.8cm, 철분코팅 6.9cm으로 각각 나타났다. 3. 유묘의 생체중은 지상부의 경우 무처리 50mg, 규산코팅 및 규산복토 40mg, 철분코팅 30mg이었으며, 지하부의 경우 규산코팅 및 규산복토 20mg, 무처리 및 철분코팅 10mg으로 각각 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.336-336
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• 2017

High mortality and slow growth of seedling generally occurred in tray due to cold, foggy weather and severe seedling blight. Mechanical transplanting is hampered, farmers having economic loss. A sustainable method for raising mat type seedling is necessary. Experiments were conducted on disease control and seedling growth in dry seasons. Fungicides treated/untreated seeds were sown 120-130g in each tray containing pulverized fine grain loam/sandy loam soils. Seed covered with a thin layer of soil and irrigated. It was polythene covered (PC) for 72h and then every night along with 2/3 sprinkler irrigation (SI) per day. Untreated seedlings infected 53-93%. Pyraclostrobin, Azoxystrobin and Azoxystrobin+Difeconazole treated seeds/sprayed (72h) seedlings had no disease. Seedling height was 11.7-13.2 cm with compact and thick root mat at 25 days. Seeds treated at 0.2-0.3% (18-20h) showed no disease but severely in untreated seeds in all locations. Seedling height (13.8 cm), leaf age (3.7) and root number (8.5) were better when NPK were applied at 3-4-3 g/tray. Spraying of urea (1%) in addition with MOP, theovit and $ZnSo_4$ at 0.6-0.6-0.2% on 7 and $15^{th}$ days was also effective. PC showed significant growth (29.1-34.5%). Root mat was not good in flooded irrigation (FI). Disease was higher in SI (66.7-97.3%) than FI (0.7-3.7%) in untreated seeds regardless of polythene use. The protocol would be effective for raising mat type seedling in cold environment.

• 한국작물학회지
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• 제43권3호
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• pp.147-151
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• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

• 한국작물학회지
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• 제51권1호
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• pp.53-58
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• 2006

This study was conducted to investigate the crossability, seed dormancy and overwintering ability of rice plant in GM (glufosinate ammonium-resistant lines. Iksan 483 and Milyang 204) and non-GM (their parents) or red rice (Andongaengmi). Seed-setting rate was not significantly different between GM and non-GM rice varieties. Iksan 483 and Milyang 204 showed the similar level of seed germination rate from 30 to 50 days after heading as compared to non-GM rice varieties. After overwintering in paddy field, seed germination rate of GM and non-GM rice varieties ranged from 14.3 % to 57.6 % in dry soil condition, but there was no germination in wet-soil except red rice. The result in wet-soil condition may help to set up a strategy for reducing the risk of gene flow of transgene via dispersal of seeds of GM plants. The crossability, seed dormancy and seed overwintering of Iksan 483 and Milyang 204, herbicide resistant GM rice varieties, were not significantly different compared to non-GM rice varieties. The results might be helpful to reduce the risk of transgene dispersal from GM crop via seeds and pollens.

• 식물병연구
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• 제14권3호
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• pp.176-181
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• 2008

본 연구는 키다리병에 심하게 감염된 종자를 온탕침법과 prochloraz 유제로 종자소독 시 그 효과가 떨어지는 원인을 규명하기 위해 시행하였다. 키다리병이 발병한 포장에서 수확한 종자의 경우 병원균이 벼 종자의 배와 배유 안쪽까지 감염되어 있었다. $60^{\circ}C$에서 10분 동안 온탕 소독한 종자의 경우 종피 표면의 균사는 파괴되어 비정상적인 반면 배 주피 안쪽에 존재하는 균사는 정상적인 형태로 존재하였다. 포자는 종피 표면에서 비정상적인 포자와 정상적인 포자를 모두 확인하였다. prochloraz 유제로 $30^{\circ}C$ 24시간 침지소독 한 경우 종피의 균사는 완전히 파괴되었으나 포자는 정상과 비정상 포자 모두 확인할 수 있었다. 이러한 결과를 통해 온탕소독의 경우 종피 같은 물리적 한계로 인해 고열이 병원균에 전달되지 못하고, prochloraz의 경우 병원균 포자를 완전히 사멸시키기 못하기 때문에 종자소독 효과가 떨어짐을 알 수 있었다.

• 한국작물학회지
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• 제44권1호
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• pp.32-37
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• 1999

The experiment was conducted to investigate emergence response of lowland weeds at different soil moisture contents, burying depths and upon changes in soil moisture. Rice germination was over 50% at all burying depths under aerobic condition, but the emergence rate of the soil surface placed seeds in saturated and flooded conditions decreased by 19% and 29%, respectively, as compared with that of aerobic condition. Rice seeds at burying depth of over 3 cm did not emerge at all. The emergence rate of Echinochloa crus­galli (L.) Beauv. in aerobic condition was lower than 30%, but the emergence pattern of E. crus galli (L.) Beauv. at different soil moisture contents and seeding depths was similar to that of rice. Emergence behavior of lschaemum rugosum Salisb., Ludwigia octovalvis (Jacq.) Raven and Sphenoclea zeylanica Gaertn. which are dominant lowland weed species in the Philippines also differed depending on soil moisture conditions and burying depths. lschaemum rugosum Salisb. emerged at all burying depths under aerobic condition, whereasLudwigia octovalvis (Jacq.) Raven emerged only at 0 cm deep under saturated and aerobic condition and Sphenoclea zeylanica Gaertn. at 0 cm deep under flooding condition. Weed seeds planted at 1, 3, and 5 cm deep in continuous flooded and saturated condition did not emerge at all, but upon a change of soil moisture condition from saturated to drainage (S$\rightarrow$D) and flooded to drainage (F$\rightarrow$D), grass weeds began to germinate again and the average emergence rate in S$\rightarrow$D and F$\rightarrow$D were 26% and 5% forE. crus­galIi (L.) Beauv., 9% and 8% forI. rugosum SaIisb., respectively. Weed seeds buried in soil in the pot showed great emergence at S$\rightarrow$D but did not emerge under continuous flooded condition. The diversity index accounting for dominance degree and occurrence aspect of weed, was the lowest at F$\rightarrow$D.