• The Plant Pathology Journal
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• v.39 no.1
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• pp.136-140
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• 2023

Rice panicle blast is one of the most serious diseases threatening stable rice production by causing severe damage to rice yields and quality. The disease is easy to occur under low air temperature and frequent heavy rainfall during the heading season of rice. In 2021, a rice panicle blast severely occurred in the Jeonbuk province of Korea. The incidence area of panicle blast accounted for 27.7% of the rice cultivation area of Jeonbuk province in 2021, which was 13.7-times higher than in 2019 and 2.6-times higher than in 2020. This study evaluated the incidence areas of rice panicle blast in each region of Jeonbuk province in 2021. The weather conditions during the heading season of rice, mainly cultivated rice cultivars, and the race diversity of the Jeonbuk isolates were also investigated. It will provide important information for the effective control of the rice panicle blast.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.412-420
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• 2015

Even though phosphorus (P) is essential element for plant growth and development, it is not enough for crop production in soil. To breed more P deficient tolerance rice, screening and selection in rice population is needed. We tried to develop more simple and rough screening method for breeding of P deficient tolerance rice. In P deficient condition, tiller number was dramatically decreased among yield components in rice. Though this result, we confirmed tiller number could be the best marker in screening of P deficient tolerance rice. 480 rice genetic resources were cultivated in rice bed tray filled with P deficient soil for four weeks and each dry weight was measured. Among them, the 55 kinds of genetic resource were selected then cultivated in paddy field with 3 fertilizer conditions. Plant dry weight and tiller number in ripening stage were shown significant difference according to P condition. Plant dry weight and tiller number in ripening stage was highly correlated especially in P deficient condition. Furthermore, the tiller number in ripening stage and plant dry weight in rough screening were shown high degree correlation. Though these results, we might expect measuring of plant dry weight after cultivation in rice bed tray filled with P deficient soil could be a simple and effective screening method in selection of P deficient tolerance rice.

• The Plant Pathology Journal
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• v.38 no.1
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• pp.46-51
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• 2022

Rice blast is the most destructive disease threatening stable rice production in rice-growing areas. Cultivation of disease-resistant rice cultivars is the most effective way to control rice blast disease. However, the rice blast resistance is easy to breakdown within years by blast fungus that continually changes to adapt to new cultivars. Therefore, it is important to continuously monitor the incidence of rice blast disease and race differentiation of rice blast fungus in fields. In 2020, a severe rice blast disease occurred nationwide in Korea. We evaluated the incidence of rice blast disease in Yeoju and compared the weather conditions at the periods of rice blast disease in 2019 and 2020. We investigated the races and avirulence genes of rice blast isolates in Yeoju to identify race diversity and genetic characteristics of the isolates. This study will provide empirical support for rice blast control and the breeding of blast-resistant rice cultivars.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.376.4-377
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• 2001

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.05a
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• pp.17-25
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• 2003

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.513-518
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• 2006

This study was conducted to investigate the relations between brown planthopper (BPH, Nilapavata lugens) resistance and specific organic acids (oxalic acid, silicic acid, and trans-aconitic acid) known as BPH sucking inhibitors on different rice varieties and/or lines. There were no specific relations between BPH resistance and the contents of oxalic and silicic acids in the rice plant tissues. However, the stronger the BPH resistance was occurred, the higher the content of trans-aconitic acid was contained in the rice plants. The relations between the injury rate of rice plant by BPH and the content of trans-aconitic acid in the rice plants were negatively correlated, which were -0.84 and -0.82 at 30 and 60 days after seeding, respectively. Therefore, the content of trans-aconitic acid in rice plant tissues might be utilized as an index for improving BPH resistance of rice varieties.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.360-366
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• 2011

Bacterial leaf spot of Euphorbia pulcherrima has been reported in many countries. Characterization by polyphasic approaches indicated that the isolates from India, USA and New Zealand could be distinguished based on rep-PCR profiles and gyrB phylogenies, while the Chinese isolates should be ascribed to Xanthomonas axonopodis pv. poinsettiicola.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.79-83
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• 2005

Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above $3\~4cm$ from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of $2.5\times2.5cm$ at rice clipping of seedling 29 days after rice seeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.262-264
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• 2005

A study on genetic variability and association of yield attributing characters with grain yield was carried out using 35 deepwater rice genotypes. High genotypic co-efficient of variation (GCV) was observed for plot yield, $EBT/m^2$, plant height and days to $50\%$ flowering (DFF). For all the traits, estimates of the phenotypic co-efficient of variation (PCV) were higher than GCV, indicating presence of environmental influence. High heritability and genetic advance was observed for plot yield, $EBT/m^2$ and plant height. Plot yield had significant positive association with test weight, $EBT/m^2$ and DFF. However, test weight had the maximum direct effect on grain yield

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.63-63
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• 2020

Rice stripe virus (RSV) disease is one of the major constraints in rice production, transmitted by the small brown planthopper (SBPH; Laodelphax striatellus). Upon RSV infection, plants develop typical symptoms, which include chlorosis and weakness of newly emerged leaves, white and yellow spots, stripe on leaves, and necrotic and wilting leaves, resulting in plant growth inhibition, oxidative damage that may culminate in programmed cell death (PCD) and plant death in severe epidemics. Although RSV-resistant quantitative trait loci (QTLs), Stv-a, Stv-b, and Stv-bi, were mapped using various resistant varieties, one RSV-resistant gene, OsSOT1, has been identified so far. In this study, we used the rice cultivar Zenith, known to carry Stv-b, to investigate novel RSV-genes through fine mapping. Therefore, we crossed Zenith (Donor parent, RSV resistant) with Ilpum (Recurrent parent, RSV susceptible) to fine-map using a BC₂F₂ population of 2100 plants. Chromosome segment introgression lines that were heterozygous at a different region were selected, two types of heterozygous lines showed an heterozygous genotype between Sid2 and Sid75 to Indel9 and RM6680. Interestingly, we identified qSTV11^Z region harboring Stv-b, covering about 171-kb region between the InDel markers Sid75 and Indel8. The localization of qSTV11^Z provides useful information that could be used for marker-assisted selection and determination of genetic resources in rice breeding.