• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.72-77
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• 2008

This study was carried out to determine the response of the rice yield and grain quality by rice leaf folder (RLF, Cnaphalocrocis medinalis G.) and identify the damages caused by different transplanting dates, nitrogen amounts and chlorophyll amounts (SPAD value) of rice leaf. As the damage degree of RLF was getting severer, the ripened grain rate and 1000-grain weight were decreased and due to the increasing of chalky rice rate the rate of head rice was reduced. Therefore, the yield of head rice was decreased by 36% in heavily damaged rice plant. Among the physicochemical characteristics, protein content of rice grain was increased but amylose content was reduced, consequently, the palatability was deteriorated in heavily damaged rice by RLF. The degree of damage of RLF was getting serious as transplanting date was delayed and as the amount of nitrogen was increased. In the relationship between the SPAD value and the damage degree of RLF, as the SPAD value was increased by nitrogen fertilizing, the damage degree was also increased exponential functionally.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.219-226
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• 2010

This paper presents the occurrence and damage characteristics of the rice leaf-folder populations in the paddy fields of Dangsu-dong, Suwon from 2004 to 2007, and also reports the insecticide response of rice leaf-folder populations, which were collected from 2005 to 2006 in Korea and Vietnam. Laboratory measurements of the head capsule width and body length data enabled the identification of the rice leaf-folder larva stages collected in the field. The rice leaf-folder population in Suwon from 2004 to 2007 has a clear pattern consisting of two different group: the low and high density years. During the low density years (2004 and 2006), only one adult peak was noted in late August, with the damaged-hill percent less than 10% in late July, and the damaged-leaf percent around 2% in September. In contrast, during the high density years (2005 and 2007), two adult peaks were noted in early August and mid-September, with the damaged-hill percent was around 30% in late July, and the damaged-leaf percent 15 to 30% in September, which was beyond the economic injury level of rice leaf-folder. High correlations existed between the occurrence of rice leaf-folder in late July and early August and damages to rice during September. Based on these results, we suggest that the information on the rice leaf-folder population monitored by the adult density or damaged-hill percent in late July and early August would be very useful for predicting the damages later in the season for aiding in decision-making for timely control. In addition, the regional populations of rice leaf-folder showed the similar responses to the insecticides tested: high susceptibility to IGRs (tebufenozide and methoxyfenozide) and organophosphates (chlorpyrifos-methyl, pyridaphenthion), but relatively low to cartap.

• Bulletin of the Korean Chemical Society
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• v.6 no.4
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• pp.228-230
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• 1985

(Z)-13-Octadecen-1-yl acetate, the pheromone mimic of the Rice Leaf Folder Moth, Cnaphalocrosis medinalis, was synthesized from 1,13-tridecanediol in three steps. Monoacetylation of 1,13-tridecanediol followed by PCC oxidation gave 13-acetoxytridecan-1-al. Wittig olefination of the 13-acetoxytridecan-1-al with pentylidenetriphenylphosphonium ylide afforded (Z)-13-octadecen-1-yl acetate, the pheromone mimic of the Rice Leaf Folder.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.104-113
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• 2011

We investigated the systemic effects of leaf folder (Cnaphalocrocis medinalis) resistant rice (transgenic rice, Nakdongbyeb) in Sprague-Dawley rats for 13 weeks. Leaf folder resistant rice was added to the diet at percentage levels of 0, 5 and 20 percentage/feeder and was administered for 13 weeks. The results did not show any changes in food and water intake. There were also no biologically significant changes in both body and organ weights, hematological and blood biochemical parameters, autopsy and histopathology between the treatment and control groups. Based on these results, no observed adverse effect level (NOAEL) of transgenic rice was considered to be more than 10,000 mg/kg b.w. under the conditions of the present study.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.200.2-200.2
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• 2007

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.183-183
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• 2005

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.115-123
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• 2009

In recent years, several genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnological companies. Commercialization of GM crops will be required the assesment of risks associated with the release of GM crops. In advance of the commercial release of GM crops, developer should submit the several information on GM crops for approval. In this study, we carried out to provide the molecular data for the risk assessment of GM rice containing insect-resistant gene, modified Cry1Ac (CryIAc1). Through the molecular analysis with CryIAc1 induced GM rice, we confirmed the steady integration and expression of transgene, the transgene copy number, the adjacent region sequences of inserted gene into rice genome, and the transgene stability in progenies. For the qualitative PCR detection methods, specific primer pairs were designed on the basis of integration sequences, and construct- and event-specific detection markers were developed for leaf folder-resistant rice, Cr7-1 line. From these results, we demonstrated that the molecular data and the PCR detection methods of leaf folderresistant GM rice could be acceptable to conduct the biosafety and environment risk assessment.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.199-208
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• 2010

To investigate a comparison of rice yield and quality between organic and conventional cultivation, study for occurrence of rice diseases carried out in rice (Oryza sativa L.) field of Noahn and Bannam region. The results obtained as following: 1) Bactericide and insecticide were applied twice and four times at Noahn and Bannam region in conventional cultivation (C.C) of rice field, respectively, it was applied twice at two region in organic cultivation (O.C). Rice strip virus, leaf blast, neck blast, sheath blight, bacterial leaf blight, rice water weevil, rice leaf folder, and plant hoppers were occurred mainly in rice field. Leaf blast, neck blast, and rice leaf folder were occurred highly at O.C compared with C.C. 2) Growth level of rice in clum and panicle length was lower at O.C than C.C. Number of panicles per hill was by 0.6 higher at O.C than C.C. Number of panicles per hill was by 0.6 higher at O.C than C.C in Noahn region. Number of spikelets per panicle, grain filling ratio, brown/rough rice ratio, and weight of 1,000 grains was lower at O.C than C.C. Number of panicles per hill was by 0.8 lower at O.C than C.C in Bannam region. Number of spikelets per panicle and grain filling ratio was higher at O.C than C.C while brown/rough rice ratio was lower at O.C. Total yield percentage of rice in O.C was level of 84% at Noahn region and 94% at Bannam region compared with C.C. 3) Head rice percentage was lower at in O.C than C.C at two region. Protein and palatability (Toyo value) were lower at O.C than C.C in Bannam region causing occurrence of neck blast and rice leaf folder by oversupply of nitrogen fertilizer. Protein, whiteness, and palatability (Toyo value) were adequate level at O.C in Noahn region by lower nitrogen fertilizer.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.327-331
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• 2006

This study was carried out to determine the economic injury level of the rice leaffolder,Cnaphalocrocis medinalis G.. The damage aspects of rice plant (at tilling stage) by leaf folders at different larval density per plant were studied in pot experiment (24 cm in diameter, 18 cm in height). One leaf folder consumed 6-7 leaves during larval stage. The damage by leaf folders was simulated by cutting off 0, 10, 30, 50, 70, and 90% of leaves before and after heading stage July 15th (at panicle initiation stage) and August 15th (at milk stage), respectively. When leaves were cut before the heading of rice, the linear relationships between the leaf cutting rate (X) and each factors of yield (Y) were as following; for grain maturity it was Y = -9.379X + 83.630 ($R^{2}=0.493$),\;Y = 0.139X + 0.490 ($R^{2}=0.925$) for yield, and Y = -4.880X + 81.116 ($R^{2}=0.665$) for head rice. When leaves were cut after the heading of rice, it was Y = -23.0l4X + 83.589 ($R{2}=0.915$), for grain maturity, Y=0.141X + 3.466 ($R^{2}=0.842$) for yield, and Y = -13.795X + 81.964 ($R^{2}=0.898$) for head rice. We found that when leaf cutting after the heading stage caused more damage than before the heading in terms of yield and yield components. Based on theses results the economic threshold level was estimated to be 30% and 7% leaf loss before and after heading stage.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.180-187
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• 2010

The study was performed to investigate the property of rhizosphere microorganisms, and community structure during GMO, and Non-GMO rice cultivation. In the dilution plate technique, there were no significant differences in microbial populations of rhizosplane with genetically modified, and non-genetically modified rice cultivation, and rhizosphere were also the same results. Dominant bacterial genera were Afipia 12.5%, Spingomonas 10.0%, Ramlibacter 10.0%, Mycobacterium 7.5%, and Tetrasphaera 7.5% in rhizosphere soil of genetically modified rice plant, while Afipia 7.3%, Spingomonas 12.2%, Ramlibacter 7.3%, Mycobacterium 17.1%, Tetrasphaera 14.6% in non-genetically modified cultivated at Suwon test fields in 2006. Majorgenera isolated from root surface cultivated in Yesan fields were Arthrobacter 12.7% in rhizoplane of genetically modified plant, and Burkholderia 22.2% of non-genetically modified plant in 2007, Paucimonas 26.6% of genetically modified plant, Chryseobacterium 15.4% of non-genetically modified plant in 2008. Also the microbial communities in rhizosphere soils of genetically modified, and non-genetically modified plants were characterized using phospholipid fatty acid, and denaturing gradient gel electrophoresis. The phospholipid fatty acid profiles of soils in this condition showed different pattern, but did not show significant differences between soils cultivated with genetically or non-genetically modified rice plants.