• 한국응용곤충학회지
• /
• 제21권2호
• /
• pp.61-67
• /
• 1982

본시험은 1974년 충남 태천지방에서 처음 발견된 딸기의 이상고사 증상의 원인을 구명코져 1977년부터 3년간 수행되었으며 그 결과를 요약하면 다음과 같다. 1. 이병주의 관부${\cdot}$잎자루${\cdot}$뿌리로부터 주로 Fusarium oxysporum균이 분리되었으며 접종시험결과 보교조생에 병원성이 있었고 이병주로부터 동균이 재분리되었다. 2. 병원균은 감자설탕 한천배지(PSA)에서 소형, 대형분생포자와 후막포자를 풍부히 형성하였다. 소형분생포자의 크기는 $5.0\~13.0\times2.5\~3.0\mu$, 대형분생포자의 크기는 $12.8\~62.5\times2.5\~5.0\mu$, 후막포자는 $7.5\~13.8\times5.5\~12.5\mu$의 범위였다. 3. 병원균의 PSA 배지에서의 균사생육은 $20^{\circ}C$ 보는 $25\~30^{\circ}C$에서 좋았으며 $35^{\circ}C$에서는 극히 낮았다. 4. 충남 태천지방에서의 병의 발생은 3월 하순부터 관찰되었으며 4월 중순에 일시 주춤하였다가 5월 초순부터 급격히 증가하기 시작하여 6월 4초순에는 $40.2\%$의 발병주율을 보였다. 5. 실내 및 포장에서의 약제시험 결과 디포라탄, 레이트티, 톱신엠의 효과가 비교적 우수하였으나 무처리에 비해 통계적 유의성은 없었다. 6. 품종저항성 검정결과 팔천대, 대학 1호, 계통 10-2, 고영, 센가센가나는 저항성, 춘향, 엠파이어는 중간성, 노드웨스트, 보교조생은 이병성이었다.

• 한국토양비료학회지
• /
• 제28권4호
• /
• pp.306-311
• /
• 1995

다양필수원소(多量必須元素)중의 하나인 유황(硫黃)이 옥수수의 초기생육에 미치는 영향을 구명하기 위하여 1995년(年) 5월(月) 22일(日) 부터 1995년(年) 7월(月) 10일(日)까지 경희대학교(慶熙大學校) 수원(水原)캠퍼스 온실(溫室)에서 옥수수 광안옥 품종(品種)과 횡성옥 품종(品種)을 공시재료(供試材料)로 하여 7주간 양액재배로 실시하였다. 유황 시비처리는 양액에 $MgSO_4{\cdot}7H_2O$를 첨가하여 조절하되 양액중 유황농도는 무류황구(無硫黃區)(-S)가 0ppm, 대조구(對照區)(C)가 68ppm, 2배시용구(倍施用區)(2S)가 136ppm, 3배시용구(倍施用區)(3S)가 204ppm이 되도록 하였다. 파종후(播種後) 매주(每週)마다 옥수수의 초장(草長), 엽면적(葉面積), 건물중(乾物重)을 조사(調査)한 결과(結果)를 보면 7주간(週間)의 생육(生育)에 있어서 광안옥 품종(品種)의 초장(草長)은 C>2S>3S>-S구(區), 엽면적(葉面積)은 2S구(區)>C구(區)>3S구(區)>-S구(區), 그리고 건물중(乾物重)은 2S구(區)>3S구(區)>C구(區)>-S구(區) 순(順)으로 신장하였고 횡성옥 품종(品種)에 있어서 초장(草長)은 C구(區)>-S구(區)>3S구(區)>2S구(區), 엽면적(葉面積)은 C구(區)>3S구(區)>2S구(區)>-S구(區), 건물중(乾物重)은 C구(區)>3S구(區)>-S구(區)>2S구(區) 순(順)으로 증가(增加)하였다. 전실험기간(全實驗期間)동안 초장(草長), 엽면적(葉面積), 건물중(乾物重)을 통합한 결과(結果)는 두 품종(品種) 공히 무류황시용구(無硫黃試用區)(-S)에서 가장 저조(低調) 하였고 횡성옥 품종(品種)에서는 C구(區)가 가장 증가(增加)하였다. 작물생장율(作物生長率)(CGR)은 두 품종(品種) 모두 파종후(播種後)부터 3주(週)까지는 완만(緩慢)한 증가(增加)를 보이다가 파종후(播種後) 4주(週)째부터는 증감(增減)이 크게 교차(交叉) 현상을 보였지만 횡성옥 품종(品種)의 C구(區)는 계속 증가(增加)하였다.

• Journal of Plant Biology
• /
• 제17권1호
• /
• pp.15-21
• /
• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• The Plant Pathology Journal
• /
• 제31권4호
• /
• pp.363-370
• /
• 2015

Using the Chinese cabbage (Brassica campestris) cultivar 'Chun-goang' as a host and turnip mosaic virus (TuMV) as a pathogen, we studied the effects of ambient temperature ($13^{\circ}C$, $18^{\circ}C$, $23^{\circ}C$, $28^{\circ}C$ and $33^{\circ}C$) on disease intensity and the speed of systemic infection. The optimal temperature for symptom expression of TuMV was $18-28^{\circ}C$. However, symptoms of viral infection were initiated at $23-28^{\circ}C$ and 6 days post infection (dpi). Plants maintained at $33^{\circ}C$ were systemically infected as early as 6 dpi and remained symptomless until 12 or 22 dpi, depending on growth stage at the time of inoculation. It took 45 days for infection of plants grown at $13^{\circ}C$. Quantitative realtime polymerase chain reaction (q-PCR) results showed that the accumulation of virus coat protein was greater in plants grown at $23-28^{\circ}C$. The speed of systemic infection increased linearly with rising ambient temperature, up to $23^{\circ}C$. The zero-infection temperature was $10.1^{\circ}C$. To study the effects of abruptly elevated temperatures on systemic infection, plants inoculated with TuMV were maintained at $10^{\circ}C$ for 20 d; transferred to a growth chamber at temperatures of $13^{\circ}C$, $18^{\circ}C$, $23^{\circ}C$, $28^{\circ}C$, or $33^{\circ}C$ for 1, 2, or 3 d; and then moved back to $10^{\circ}C$. The numbers of plants infected increased as duration of exposure to higher temperatures and dpi increased.

• 한국환경농학회지
• /
• 제38권3호
• /
• pp.185-196
• /
• 2019

BACKGROUND: This study investigated the effects of rice genetically modified to be resistant against rice blast and rice bacterial blight on the soil microbial community. A comparative analysis of the effects of rice genetically modified rice choline kinase (OsCK1) gene for disease resistance (GM rice) and the Nakdong parental cultivar (non-GM rice) on the soil microbial community at each stage was conducted using rhizosphere soil of the OsCK1 and Nakdong rice. METHODS AND RESULTS: The soil chemistry at each growth stage and the bacterial and fungal population densities were analyzed. Soil DNA was extracted from the samples, and the microbial community structures of the two soils were analyzed by pyrosequencing. No significant differences were observed in the soil chemistry and microbial population density between the two soils. The taxonomic analysis showed that Chloroflexi, Proteobacteria, Firmicutes, Actinobacteria, and Acidobacteria were present in all soils as the major phyla. Although the source tracking analysis per phylogenetic rank revealed that there were differences in the bacteria between the GM and non-GM soil as well as among the cultivation stages, the GM and non-GM soil were grouped according to the growth stages in the UPGMA dendrogram analysis. CONCLUSION: The difference in bacterial distributions between Nakdong and OsCK1 rice soils at each phylogenetic level detected in microbial community analysis by pyrosequencing may be due to the genetic modification done on GM rice or due to heterogeneity of the soil environment. In order to clarify this, it is necessary to analyze changes in root exudates along with the expression of transgene. A more detailed study involving additional multilateral soil analyses is required.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.284-284
• /
• 2022

The overall effects of gibberellic acid (GA3) with NaCl on different rice genotypes are inadequately understood. The present study determines the effect of different GA3 concentrations on the morphophysiological, molecular and biochemical effects of 120 mM NaCl salt stress in rice seedlings. Salt stress reduced germination percentages and seedling growth and decreased bioactive GA content. It also downregulated the relative expression of a-amylase-related genes - OsAmy1A, OsAmy1C, and OsAmy3C in the salt-sensitive IR28 cultivar. Salt stress differentially regulated the expression of GA biosynthetic genes. Salt stress increased antioxidant activity in all rice genotypes tested, except in IR28. GA3 (50 and 100 µM) mitigates the effect of salt stress, rescuing seed germination and growth attributes. GA3 significantly increased bioactive GA content in Nagdong and pokkali (50 µM) and Cheongcheong and IR28 (100 µM) cultivars. The a-amylase genes were also significantly upregulated by GA3. Similarly, GA3 upregulated OsGA2oxl and OsGA2ox9 expression in the Cheongcheong and salt-sensitive IR28 cultivars. The present study demonstrated that salt stress inactivates bioactive GA - inhibiting germination and seedlings growth - and decreases bioactive GA content and GSH activity in IR28 and Pokkali cultivars. Further, GA3 significantly reversed the effects of 120 mM NaCl salt stress in different rice genotypes. The current study also suggests if we know the coastal area water NaCl concentration we can apply the exogenous GA3 accordingly. Thus, we would be able to grow rice cultivars near the coastal area and reduce the rice damage by salinity.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1994년도 94 Symposium on Plant science September 10, 1994 Ewha Womans University, Seoul, Korea 94 식물학 심포지움 환경 스트레스와 식물의 반응
• /
• pp.29-39
• /
• 1994

Serious issues about the changes in the environmental conditions on earth associated with human activities have arisen, and the interest in these problems has increased. It is urgent to determine how the expansion of terrestrial UV-B radiation due to the stratospheric ozone depletion influences living matters. In this connection, we have been investigating the effects of UV-B radiation on the growth of rice cultivars (Oryza sativa L.). We report here some physiological and genetic aspects of resistance to inhibitory effects of UV-B radiation on growth of rice cultivars as described below. Elevated UV radiation containing large amount of UV-B and a small amount of UV-C inhibited the development of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Similar results were obtained in experiments, in which elevated UV-V radiation. Similar results were obtained in experiments, in which elevated UV-B radiation (transmission down to 290 nm) was applied instead of UV-B radiation containing a small amount of UV-C. The inhibitory effects of UV radiation was alleviated by the elevated CO2 atmospheric environment or by the exposure to the high irradiance visible radiation. The latter suggested the possibility that the resistance to the effects of UV radiation was either due to a lower sensitivity to UV radiation or to a greater ability to recover from the injury caused by UV radiation through the exposure to visible radiation. The examination of cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes (aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups showed the following: Various cultivars having different sensitivities to the effects of UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to UV rakiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultuvars are cultivated. Form the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F2 plants generated by reciprocally crossing Sasanishiki and Norin 1 and F3 lines generated by self-fertilizing F2 plants, it was evident that the resistance to the inhibitory of elebated UV radiation in these rice plants was controlled by recessive polygenes.

• Current Research on Agriculture and Life Sciences
• /
• 제33권2호
• /
• pp.69-73
• /
• 2015

The antioxidant capacities, total phenolic contents (TPC), and total quercetin contents (TQC) of a red (Chenjujuck), a yellow (Sunpower), and a white (Grasier) onion cultivar were determined in this study. Onion was separated into edible portion and dry skin. In the case of edible portion, the yellow onion had the highest antioxidant activity, followed by the red onion. The white onion showed neither antioxidant activity nor quercetin compounds. On the other hand, the dry skin of the red onion showed higher antioxidant activity than yellow onion skin. The white onion skin had slight antioxidant activity, low TPC, and no quercetin compounds. In addition, the flavonoid compounds of the edible portion and dry skins of these colored onions were analyzed by UFLC(ultra-fast liquid chromatography). The major compounds were quercetin 3,4-diglucoside and quercetin 4-glucoside in yellow and red onion edible portion, whereas the major compounds in yellow and red onion skins were quercetin 4-glucoside, quercetin, and quercetin 3,4-diglucoside.

• 한국작물학회지
• /
• 제45권2호
• /
• pp.88-92
• /
• 2000

Excessive soil water in paddy field induces growth losses during the vegetative stages of soybean plants. Our objectives were to know growth responses of soybean as affected by the level of ridge heights. A field experiment was conducted at the Research Farm of Korea University near Seoul in 1996. Ten cultivars of soybean (Glycine max (L.) Merrill) were planted at the ridge heights of 10, 30, and 50cm in paddy soil on 27 June. Total dry matter accumulation at the 10cm ridge height was severely decreased until the growth stage of R5 as compared to the ridge heights of 30 and 50cm, and this decrement was mainly due to both reduced leaf and stem dry weights. However, seed dry weight was not significantly decreased at the lower ridge height with the increment of harvest index. Cultivar differences were found on seed dry weight, crop growth rate from R1 to R5, and leaf/stem ratio of R5. From the above results, soybean growth responses to excessive soil water in paddy field were different between seed filling stage and late vegetative to early reproductive growth stages.

• 한국작물학회지
• /
• 제52권1호
• /
• pp.55-59
• /
• 2007

This experiments were conducted to evaluate suitable plant-type and cultivars for producing fresh pod peanut from late seeding as succeeding crop, compared with early seeding as proceeding crop or single cropping. 12 cultivars according to grain weight and plant types, 6 virginia typed cultivars(ssp. hypogaea) and 6 shinpung typed cultivars(ssp. fastigiata), were used for early and late seedings. The plant growth and yield potential in early seeding were better than those in late seeding. But the ratios of dry/fresh pod and of mature pod in late seeding were higher than those of early seeding. The yield of fresh pod by cultivars in two seeding times showed significant correlation with pod scale such as fresh pod weight, 100-grain weight, and dry seed yield positively, but pod number negatively in early seeding only. Yield of fresh peanut between Virginia and Shinpung types didn't show significant difference in early seeding, but showed in late seeding. Average yield of Virginia typed cultivars showed significantly higher than that of Shinpung typed ones. This yield gap between two plant types was the same tendency on extending seedings to July 20.