Grain size is a major determinant of grain yield in rice. In a previous study, a QTL for grain width(GW), qgw1 was detected on chromosome 1 using 96 BC3F8 lines derived from a cross between ‘Hwaseongbyeo’ as a recurrent parent and ‘O. rufipogon’ as a donor parent. At this locus, the O. rufipogon allele increased GW. Among the 96 introgression lines, three ILs with the O. rufipogon qgw1 locus showed significantly increase in grain width compare to the recurrent parent. One of the three lines, CR572 was selected and crossed to ‘Hwaseongbyeo’. A total of 494 F2:3 were evaluated for grain width and agronomic traits in the field. QTL analysis in 494 F2:3 lines indicated that QTL for grain width was located in the interval RM495–RM5443. To narrow down the position of qgw1, substitution mapping using F4 lines with different cross-over breakpoints in the region is underway. The result will be discussed.

High grain yield is one of the most important traits for improvement in rice breeding program. Much attention has been given to the genetic bases of spikelets per panicle (SPP) and grain weight (GW) because of their imporftance in rice yield. In this study, IL28, near isogenic line (NIL) developed by introgressing chromosomal segments from Moroberekan into Ilpumbyeo, showed significant increase in number of spikelets per panicle and 1,000 grain weight compare to the recurrent parent Ilpumbyeo. Quantitative trait locus (QTL) analysis in 1150 F2 plants derived from a cross between IL28 and Ilpumbyeo, indicated that both qspp6 and qgw6 were located in the interval RM3430 – RM20580. To map the QTL more precisely, substitution mapping of qspp6 and qgw6 using F4 lines was conducted. As a result of substitution mapping with fifty F4 lines, qspp6 was mapped to an 429kb interval between RM20521 and RM20562 while qgw6 was mapped to a 267kb interval between RM20562 and RM20572 based on the japonica genome sequence. This result seems to indicate that qspp6 and qgw6 are two different genes. It is notable that these QTL, qspp6 and qgw6 are independence from undesirable height and flowering time. Moreover, there was no negative correlation between qspp6 and qgw6 when two genes are pyramided in the genetic background of Ilpumbyeo. SSR markers tightly linked to the qspp6 and qgw6 will facilitate cloning of the gene underlying these QTLs as well as marker assisted selection for variation in SPP and TGW in an applied breeding program.

The Brown planthopper (Bph) is one of the most serious pests of rice affecting rice yield and quality throughout the country. Combining the Bph resistance in the existing quality japonica cultivars is an important breeding target in Korea. Wide crosses using several strains of AA-genome wild rices, O.rufipogon have been used to produce the primary germplasm which is highly resistant to Bph. By repeated backcrossing, the resistance gene was introgressed in the background of two japonica cultivars, Ilpum and Hwaseong. Among the advanced backcross progenies, the ten BC2F3 lines were identified as the highest resistance in the comparative Bph bioassay with other resistant sources. The 24 polymorphic markers spanning the twelve chromosomes were tested for association with marker genotypes and resistance/susceptibility reaction in the 80 BC2F3 lines, RM3748 on the chromosome 7 showed the highest association.

In previous studies, we reported that a QTL for 1000-grain weight (TGW), qTGW3 was located in the interval between RM60 and RM523 (1.2Mb) on chromosome 3 using advanced backcross lines derived from a cross between Oryza sativa ssp. Indica cv. Milyang 23 and O. glaberrima. The O. glaberrima alleles at this locus increased TGW and GL in the Milyang 23 background. To further confirm and narrow down the position of the QTLs on chromosome 3, twenty lines with different O. glaberrima segments in the target region were selected. Twenty lines were evaluated for seven agronomic traits including 1,000 grain weight and grain length and also genotyped with ten SSR markers. Sixteen lines(A, B, C groups) with the O. glaberrima segment flanked by SSR markers, RM60 and RM7332 displayed significantly higher values than Milyang 23 in TGW and GL whereas four lines(D, E groups) without the O. glaberrima segment displayed no difference in TGW and GL. The result indicates that two QTL, qTGW3 and qGL3 are located near RM60 and RM7332.

Anthropogenic increases in greenhouse gas concentrations, primarily through radiative forcing from carbon dioxide, continue to challenge earth’s climate. This study quantified CO2 storage and uptake by dominant forest types and age classes in the middle region of Korea. In addition, the role of forest landscapes in reducing atmospheric CO2 against CO2 emissions based on energy consumption was evaluated. Mean CO2 storage and uptake per unit area by woody plants for three forest types and four age classes were estimated applying regression equations derived to quantify CO2 storage and uptake per tree; and computations per soil unit area were also performed. Total CO2 storage and uptake by forest landscapes were estimated by extrapolating CO2 storage and uptake per unit area. Results indicated mean CO2 storage per unit area by woody plants and soils was higher in older age classes for the same forest types, and higher in broadleaved than coniferous forests for the same age classes, with the exception of age class II (11-20 years). CO2 storage by broadleaved forests of age class V (41-50 years) averaged 662.0 t/ha (US$331.0 hundred/ha), highest for all forest types and age classes evaluated. Overall, an increased mean CO2 uptake per unit area by woody plants was evident for older age classes for the same forest types. However, decreased CO2 uptake by broadleaved forests at age class V was observed, compared to classes III and IV with an average of 27.9 t/ha/yr (US$14.0 hundred/ha/yr). Total CO2 storage by woody plants and soils in the study area was equivalent to 3.4 times the annual CO2 emissions, and woody plants annually offset the CO2 emissions by 17.7%. The important roles of plants and soils were associated with 39.1% of total forest area in South Korea, and CO2 emissions comprised 62.2% of the total population. Therefore, development of forest lands may change CO2 sinks into sources. Forest landscape management strategies were explored to maintain or improve forest roles in reducing atmospheric CO2 levels.

Notch signaling plays fundamental roles in various animal development. It has been suggested that Hr-Notch, a Notch homologue in the ascidian Halocynthia roretzi, is involved in the formation of peripheral neurons by suppressing the neural fates and promoting the epidermal differentiation. However, roles of Notch signaling remain controversial in the formation of nervous system in ascidian embryos. To precisely investigate functions of Notch signaling, we have isolated and characterized Hr-Numb, a Numb homologue which is a negative regulator of Notch signaling, in H. roretzi. Maternal expression of Hr-Numb mRNAs was detected in egg cytoplasm and the transcripts were inherited by the animal blastomeres. Its zygotic expression became evident by the early neurula stage and the transcripts were detected in dorsal neural precursor cells. Suppression of Hr-Numb function by an antisense morpholino oligonucleotide resulted in larvae with defect in brain vesicle and palps formation. Similar results have been obtained by overexpression of the constitutively activated Hr-Notch forms. Therefore, these results suggest that Hr-Numb is involved in Notch signaling during ascidian embryogenesis.

Spikelets per panicle (SPP) is one of the most important traits associated with rice yield. In this study, IL28, a near isogenic line (NIL) developed by introgressing chromosomal segments from ‘Moroberekan’ into ‘Ilpumbyeo’ showed significantly higher number of spikelets per panicle than the recurrent parent, ‘Ilpumbyeo’. Quantitative trait locus (QTL) analysis in 243 F2 plants derived from a cross between IL28 and Ilpumbyeo indicated that a QTL for spikelets per panicle, qSPP6 was located in the interval RM3430 - RM20580. The Moroberekan allele increased SPP. The fact that QTLs for panicle length and the number of secondary branches were mapped in the same interval as qSPP6 appears to indicate that this locus was associated with panicle structure. To map the QTL more precisely, substitution mapping of qSPP6 using F3 lines was conducted. Substitution mapping with 41 F3 lines further narrowed the interval containing not only qSPP6 for spikelets per panicle but also qNDW6 for node width to about 680-kb between markers RM20521 and RM20572 based on Nipponbare genome sequence. The locus, qSPP6 is of particular interest because of its independence from undesirable height and flowering time. SSR markers tightly linked to the qSPP6 will facilitate cloning of the gene underlying this QTL as well as marker assisted selection for variation in SPP in the breeding program.

In direct-seeding cultivation of rice, the emergence and establishment of seedlings are important for determining the actual yield. These traits depend principally upon elongation of both the mesocotyl and coleoptile. Mesocotyl elongation in rice is controlled by several genetic factors and is also affected by environmental factors. In this study, we mapped QTL for mesocotyl elongation using F8 lines from a cross between the cultivated rice, Ilpumbyeo and a weedy rice, PBR. One of the Korean weedy rice, PBR showed the long mesocotyl length than that of cultivars, Ilpumebyeo under soil and agar media conditions. This weedy rice showed long mesocotyl than the elite japonica cultivars. After a phenotyping of 150 F7 lines for mesocotyl length, a subset of 20 lines selected from the two extreme phenotypic tails was used for the bulked segregant analysis. Two QTL were identified on chromosomes 1 and 3. These two QTL were confirmed using 120 F8 lines. Two QTL, qMel-1 and qMel-3 on chromosomes 1 and 3 accounted for 37.3% and 6.5% of the phenotypic variance, respectively. The PBR alleles were associated with an increase in mesocotyl elongation at both loci. It is noteworthy that two QTL for mesocotyl elongation were colocalized with the QTL for mesocotyl length reported in the previous QTL reports. These QTLs can be introgressed into cultivar background using marker assisted backcrossing in an effort to enhance the level of mesocotyl elongation.

Brown leaf spot, caused by necrotrophic Cochliobolus miyabeanus (imperfect; Bipolaris oryzae), is one of the devastating disease in rice (Oryza sativa). Especially, recommended agricultural system such as diminishing fertilizer and environmental alteration like temperature increment result in the favorable conditions for the outbreak of this disease. Lack of water supply also requires drought-tolerant rice cultivar. We hypothesized that regulation of programmed cell death (PCD) should be a common solution conferring resistance and tolerance against above biotic and abiotic stresses at the same time. Among 17 CYCLIC NUCLEOTIDE-GATED ION CHANNEL in rice (OsCNGCs), over expression of a CNGC resulted in lesion mimic phenotypes in Dongjin background. Further, knock out of a CNGC resulted in enhanced resistance against rice brown spot in the field. These results indicate that selected OsCNGC should be involved in the PCD regulation and fungal infection-specific regulation of OsCNGC expression might induce resistance against rice brown spot because of pathogen’s necrotrophic nature. Vitamin E, tocopherol, is involved in the accumulation inhibition of reactive oxygen species involving superoxide and hydrogen peroxide. Tocopherol cyclase in Nicotiana benthamiana (NtTC), which is included in tocopherol systhesis, conferred tolerance against drought stress to rice. We already have settled down the recombination system effectively removing selection markers in vector. Based on these systems, we will define fungal secretome and genome, confirmation of PAMPs/effectors, identification of rice pattern recognition receptor, and functional characterization of these rice genes in the respect of PCD and disease resistance. We will also develop marker-free transgenic rice tolerant to drought and/or salinity stresses. These works should give us a bundle of rice genes conferring resistance and tolerance against biotic and abiotic stresses and amount of information useful for the analyses of common cross talk points between disease resistance and stress-tolerance.

The objective of this study were to identify QTLs for agronomic traits using a set of introgression lines carrying wild rice (Oryza rufipogon) segment in cultivated rice (ssp. japonica cv. Hwaseongbyeo). Ninety-six ILs were evaluated for seven agronomic traits, amylose and protein contents. The proportion of the recurrent genome in ILs ranged from 87.8 to 100%, with an average of 96.7%. The mean number of homozygous and heterozygous donor segments were 2 (ranging 0-7) and 1.7 (ranging 0-6), respectively, and the majority of these segments had size less than 10 cM. A total of 22 quantitative trait loci were identified for 9 traits and each QTL explained 7.2% to 56.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM527 on chromosome 6 with QTLs for culm length, panicle length, days to heading, 1000-grain weight and protein content. Three ILs with high spikelets per panicle compared to the recurrent parent were selected to detect and fine map the wild segments responsible for this variation. The results will be discussed.

Spikelets per panicle is one of the most important trait associated with rice yield component. In this study, IL28, near isogenic line (NIL) developed by introgressing chromosomal segments from Moroberekan into Ilpumbyeo, showed significantly higher number of spikelets per panicle than the recurrent parent Ilpumbyeo. Quantitative trait locus (QTL) analysis in 243 F2 plants derived from a cross between IL28 and Ilpumbyeo, indicated that a QTL for spikelets per panicle, qspp6, located in the interval RM3430 – RM20580. The fact that QTLs for panicle length and secondary branch number were mapped in the same interval as that for qspp6 indicated that this locus was associated with panicle structure. To map the QTL more precisely, substitution mapping of qspp6 using F4 lines was conducted. As a result, substitution mapping with ten F4 lines further narrowed the interval containing qspp6 to about 429kb between marker RM20521 and RM20562 based on the japonica genome sequence. The locus, qspp6 is of particular interest because of its independence from undesirable height and flowering time. SSR markers tightly linked to the qspp6 will facilitate cloning of the gene underlying this QTL as well as marker assisted selection for variation in SPP in an applied breeding program.

The cereal grain crops have strong flexibility against adverse environment and they have various functional compounds. The objective of the present study was to screen phenolic compounds in sorghum [Sorghum bicolor (L.) Moench], foxtail millet (Setaria italica), common millet (Panicum miliaceum L.) by high performance liquid chromatography (HPLC) with photodiode array (PDA) detector. Sorghum contained the highest amount of phenolic compounds among three different crops (sorghum, foxtail millet, common millet). Especially Moktaksusu showed the highest amount of phenolic compounds concentrations and biggest regional differences. The comparison of average phenolic compounds in sorghums by regions showed order to Milyang (963.3~;~mug~cdotg-1 ), Yeongyang (923.1~;~mug~cdotg-1 ), Gijang (831.3~;~mug~cdotg-1 ) and Bonghwa (735.6~;~mug~cdotg-1 ). Among the sorghum cultivars, Moktaksusu (1407.9~;~mug~cdotg-1 ) had the highest concentration of phenolic compounds. The average phenolic compounds of foxtail millets showed similar amount among Milyang (319.0~;~mug~cdotg-1 ), Gijang (288.1~;~mug~cdotg-1 ) and Bonghwa (281.9~;~mug~cdotg-1 ) areas. The phenolic compounds of Yeongyang (246.6~;~mug~cdotg-1 ) slightly low and that showed similar concentrations among three different regions. The concentration of phenolic compounds in foxtail millets, Chungchajo (335.6~;~mug~cdotg-1 ) showed the highest concentrations. The average phenolic compounds of common millets showed the highest concentrations in Milyang (305.5~;~mug~cdotg-1 ), Bonghwa (262.0~;~mug~cdotg-1 ), Gijang (195.1~;~mug~cdotg-1 ), Yeongyang (237.2~;~mug~cdotg-1 ) in decreasing order. The concentration of phenolic compounds of common millets was the highest in the Norangchalgijang (337.0~;~mug~cdotg-1 ), Hwanggumgijang (250.0~;~mug~cdotg-1 ) was also relatively higher than others. The results of this study will provide basic information for breeding sorghums, foxtail millets and common millets with higher phenolic compound concentrations.

MicroRNAs (miRNAs) function as a key regulator of diverse cellular functions. To find out novel miRNAs that promote the differentiation of mouse embryonic stem cells (mESCs), we compared the miRNAs expression profiles of mESCs under self-renewal vs. differentiation states. We noticed that miR-222 was highly expressed during the differentiation of mESCs. Quantitative RT-PCR analysis revealed that expression of miR-222 was up-regulated during the embryonic bodies formation and retinoic acid -dependent differentiation. When miR-222 was suppressed by antogomiR-222, the differentiation of mESCs was delayed compared to control. Self-renewal marker expression or cell proliferation was not affected but the expression of lineage specific marker was suppressed by the treatment of miR-222 inhibitor during the differentiation of mESCs. Taken together, these results suggest that miR-222 functions to promote the differentiation of mESCs by regulating expression of differentiation related genes.

Beta-carotene producing transformants were produced in the background of 'Nagdongbyeo', a Japonica rice cultivar. Introgression of the carotenoid locus in the transformant, PAC4-2 into the elite cultivar 'Ilpumbyeo' was started. To initiate a backcrossing program, we surveyed 220 SSR markers and found that 38% of them were polymorphic between 'Ilpumbyeo' as a recurrent parent and the PAC4-2 as a recipient parent. The selection strategy comprising foreground and background selection was employed. First, foreground selection was practiced in BC1, BC2, and BC3 generations using the transgene specific PCR-based marker in addition to visual scoring of the seed color. Marker-based background selection combined with phenotypic selection was employed from BC3F2 to BC3F4 generations. Blast search indicated that the transgene PAC4-2 was located between SSR markers, RM6 and RM482. 240 BC3F3 and 63 BC3F4 lines were evaluated for four agronomic traits including days to heading. Most of the lines were similar to Ilpumbyeo in agronomic traits evaluated. The percentage of PAC4-2 genome ranged from 4% to 21% with a mean of 12.5%, which was higher than the expected for an unselected BC3 backcross population. This could be explained by the fact that two genes for beta-carotene and the stripe virus resistance were targeted in this study. We selected 10 representative BC3F5 lines from 63 BC3F4 lines based on agronomic traits and carotenoids content. The selection strategy would be appropriate for the introgression of beta-carotene gene in a breeding program.