Grain weight (GW) or grain size is the most important target not only as a major component of grain yield, but also associated with the cooking quality in rice breeding program. In a previous study, two loci for grain weight, gw8 and gw9, have been fine map to about 306.4kb and 37.4kb, respectively, in backcross populations derived from a cross between the Korean japonica cultivar Hwaseongbyeo and Oryza rufipigon (IRGC 105491). Both O.rufipogon alleles increased GW in the Hwaseongbyeo background despite the fact that O. rufipogon was the small-seeded parent. To test the effect of pyramiding the QTLs for grain weight, an F2 population consisted of 226 individuals was developed derived from the cross between the two QTLs (gw8 and gw9), and used MAS to select nearly isgenic lines for two QTLs and a pyramiding line. Molecular genotyping of F2 population revealed the existence of interaction between gw8 and gw9. Moreover, the interaction was also confirmed by phenotypic analysis of four QTL-NILs. The results suggest that epistasis interaction is important genetic basis in determining yield traits in rice.

Corn (Zea mays. L) is one of the potential export crops of Myanmar. It is crucial to develop locally adapted high yielding hybrids to dramatically increase production. International Corn Foundation/Kyungpook National University (ICF/KNU) and Department of Agricultural Research (DAR) have developed a collaborative research to develop super hybrids. Under this program, 11 preliminary test cross trials including 538 crosses were tested in AungBan and NyaungMon (mid altitude) and Tatkone (lowland) Myanmar, and ICF Agric Center in Cambodia, 2008 rainy season. Test cross seeds were produced in Cambodia and Myanmar during 2007 winter season. Germplasms from Nepal, Myanmar, IITA, and CIMMYT were used. Simple estimates of commercial value score (1= best, 9= poorest) with yield potential, good agronomic traits and disease tolerance were rated. The analysis of variance for each trial showed highly significant among test crosses and better performance than local check hybrids. VN3 x SSA showed the highly tolerance to Northern Corn Leaf Blight in sticky corn trial. The outstanding performance was recognized in Nepal materials crossed with IITA materials. It is point out that overseas aids collaborative breeding and training of young staff are effective parts of Myanmar hybrid corn R&D program.

Field resistance is defined as the resistance that allows effective control of a parasite under natural field condition and is durable when exposed to new races of that parasite. To identify the genes for field resistance against rice blast, quantitative trait loci (QTLs) conferring field resistance in japonica rice cultivars were detected and mapped using SSR markers. QTL analysis was carried out in 190 RILs population from the cross between Suweon365 (moderately resistance) and Chucheong (highly susceptible). Fourteen QTLs for nine blast races inoculated were detected on chromosomes 1, 2, 4, 5, 6, 7, 11 and 12. They explained from 6.4 to 39.7% of total phenotypic variation. Eight QTLs for blast nursery screening in 4 regions for three years were detected on chromosomes 1, 2, 4, 5, 11 and 12. The phenotypic variation was explained by each QTL ranged from 5.9 to 38.0%. Three BC2F5 backcrossed progeny lines were developed to transfer the QTLs into the susceptible cultivar Chucheong as a recurrent parent. A NIL4 containing two QTLs Qbl6.2 and Qbl7 for blast races showed the reaction 6 to 7 in blast nursery in 2007 and 2008, respectively. Two lines NIL143 and NIL93 containing Qbl11.2 and Qbl12.1 for QTLs related with field resistance, respectively, were 3 to 4 reactions in blast nursery.

A population of 120 double-haploid lines derived from Samgang/Nagdong was used for analyzing the developmental behaviors of plant height and tiller number by conditional mapping via composite interval approaches at five growth stages of rice. The traits were normally distributed with transgressive segregations in both directions. A total of 4 QTLs associated with plant height were identified in 40th/initial, 50th/40th and 60th/50th periods, respectively. The qph7.1 was observed in 50th/40th and 60th/50th periods, with increasing effects from Samgang and Nagdong alleles, respectively. This indicated that an individual gene or genes at the same genomic region might have opposite genetic effects at various growth stages. Five QTLs associated with tiller number were identified in four stages except 60th/50th stage. Four of five increasing effects of QTLs were from Nagdong alleles. Six of nine QTLs for two traits were detected before 60 days. It was evident that the expression of QTLs for plant height and tiller number was more active at early stages than at maturity stage. Furthermore, QTLs identified at early stages showed opposite additive effects on plant height and tiller number. These results provided a possible genetic explanation for the negative correlation between two traits.

A gene flow has been tested from transgenic herbicide-resistant Chinese cabbage to major crops in Cruciferae. Hybridizations were made between transgenic Basta-resistant Chinese cabbage and non-transgenic Chinese cabbage, B. napus, B. juncea and Brassicoraphanus(B. campestris × Raphanus sativus, 2n=4x=38) with honey-bee mediated fertilization. Progeny populations were selected by Basta herbicide. The F1 hybrids with pat gene were again self-pollinated or cross-pollinated with nontransgenic Chinese cabbage and rape naturally or artificially. Pod setting ratio were compared as a tentative parameter for potential gene flow. Key agronomic characters were compared among the F1 hybrid populations obtained. In the days to flowering after cold treatment, the F1 hybrids of Brassicoraphanus x B. campestris and B. napus x B. campestris(GM) were the shortest (75 days), and the GM Chinese cabbage and the F1 hybrid of B. juncea x B. campestris(GM) were 87 and 93 days, respectively. In the stem length, the F1 hybrid of Brassicoraphanus x B. campestris was the longest(175 cm), and followed by the F1 hybrid of B. napus x B. campestris(GM), the F1 hybrid of B. juncea x B. campestris(GM) in order. The naturally occurring pod setting ratios were fluctuated seriously among individual and segregation lines. Natural pod setting of the transgenic Chinese cabbage was 10 to 19 %. The F1 hybrid of B. napus x B. campestris(GM) showed the ratio of 4-11%. However, the F1 hybrids of B. juncea x B. campestris and Brassicoraphanus x B. campestris(GM) did not produced seeds. The F1 hybrids with pat gene were hybridized with nontransgenic Chinese cabbage and rape by artificial bud pollination to test potential gene flow. All cross combinations except Brassicoraphanus produced seeds and the pod setting ratios ranged from 35 to 100 percentages. Thus, the potentials of the gene flow from Chinese cabbage with pat gene to the order specise in the same gene interspecies or intergeneric species and from the F1 hybrids with pat gene to nontransgenic Chinese cabbage and rape were detected. Herbicide resistant test to the acquired seeds by natural and artificial pollinations including honey-bee mediated fertilization using the same materials is going on.

This study was conducted to make breeding program for improving milling traits, which has difference among the rice varieties. Milling traits such as residual embryo ratio, broken kernel ratio and whiteness were investigated at the different milling level and with several varieties. Residual embryo ratio and broken kernel ratio were high at the varieties group having more 1000-grain weight. In the whiteness of milled rice, there was also variance among the varieties at the same degree of milling. Correlation analysis among milling traits showed that there is positive correlation between 1000-grain weight and recovery of brown rice, but negative correlation between protein content of brown rice and hardness of kernel. Therefore, these different milling traits of each varieties could be considered in the rice breeding program for the good quality.

Cold sensitivity has been shown to vary and the cold tolerance from vegetative to reproductive stage appears to be independent during the life cycle. In the current study, cold tolerance under high elevation rice growing area were evaluated using F4 generation of 181 lines derived from Gayabyeo*2/Chhamrong. Five main-effect QTLs related to days to heading, panicle exertion and spikelet fertility were identified. The QTL qDH-3 on chromosome 3 showed the peak LOD score of 6.3, explaining up to 16.5% of phenotypic variation with additive effect of -2.6. Moreover, the QTL qPE-3 and qSF-3 on chromosome 3 were coincided with the QTL qDH-3 showing an opposite allele effects. Thus, the region harboring marker RM523-RM14281 could be helpful for the selection of cold tolerance genotypes in marker assisted selection(MAS) of rice breeding program.

Cold tolerance at every growing stage of rice(Oryza sativa L.) is one of the main determinations for the stable growth in temperature and high elevate area. In the current study, a 181 lines of BC population derived from a cross of Gayabyeo, a Tongil type sensitive to cold and Chhamrong a tolerant to cold were evaluated for cold tolerance with cold water irrigation(17℃) at seeding stage as well as low temperature germinate at 13℃, respectively. The resulting linkage map consists of 157 marker loci, covering all of 12 rice chromosomes and spanning 910cM(Haldane function) with an average interval of 76cM between markers. Three main-effect QTLs were identified. The comparison of the OTLs identified in this cold treatments resulted in an intriquing finding that each treatments were controlled by a major QTL. The QTL qCWI-4 on chromosome 4 was found to increase its additive effect to -0.84 as the cold water irrigate stress was given. In the meanwhile, the QTL qLTG-8 was detected with a LOD score of5.54, explaining up to 13% of the phenotypic variation controlled by Gayabyeo allele. In addition, the QTL qLTGV-3, controlled by Gayabyeo allele with a LOD score of 5.19 explaining about 12.5% of the variation was also identified. These results would favor our better understanding of the genetic control of cold tolerance in rice and be important for the development of rice cultivars with a broaden climatic adaptation.

Sucrose synthase 3 which is a third active gene present in rice, is localized predominantly in rice endosperm. This sucrose synthase 3 may play an important role in the starch filling in the milky stage rice seed, probably involving in the starch physicochemical properties. As the genetic diversity at this locus is little informed, forty three rice consisting of japonica, indica and Oryza rufipogon were targeted to amplify full sequence of sucrose synthase 3 to examine the frequency and distribution of nucleotide polymorphism. Total of 755 all sequence variants detected, 491 single nucleotide polymorphisms (SNPs) and 264 indels were successfully identified in 7618 bp of sequence containing the sucrose synthase 3 transcript, promoter and 3' non-transcribed region. The frequency of nucleotide changes and indels were high, on average one polymorphism per 15.5 bp and one indel per 28.9 bp with 11 sequence-based haplotypes distinguishable among the varieties and lines. Both the frequency of nucleotide changes and indels were frequent in non-coding region, but rare in coding region. Sequencing a polymorphism region in the promoter showed one base change on one of cis-element from T (CATGCATA to A (CATGCACA) that might implicate in seed specificity. The presence of a high number of haplotype shared by a few varieties indicated a little information on linkage disequilibrium.

The giant embryo(ge) mutation was genetically mapped to chromosome 7 by Koh et al. The ge mutations were analyzed at the morphologic and genetic level by Hong et al. And this publication linked the GE gene as being required for proper endosperm development. Researchers in Dupont cloned the GE gene, sequenced and characterized the ge alleles of the mutants. the three giant embryo mutant lines we obtained by treating MNU to Hwacheongbyeo, a japonica type Korean rice cultivar, differed in their embryo and endosperm size and their embryo/endosperm ratios. We named these alleles affecting the embryo size in rice GE, ge-m, ge, ge-s (GE: the wild type, ge-m: embryo slightly larger than in the wild type, ge: large embryo, ge-s: embryo even larger than in ge). The ORFs and introns of the four different alleles in the GE locus were sequenced and compared with the corresponding sequences in the patent that dupont presented. Each mutant alleles sequence showed a few SNPs in the ORF region. Two SNPs were shared among the three mutant lines and each mutant line hab one or two additional SNPs. Further studies are in progress regarding the GE RNA expression level in each mutant line and the F1 seed phenotypes and allelism relationship among the mutant lines.

Japonica rice cultivars exhibit high susceptibility to BB disease due to genetic vulnerability in Korea. Korean Japonica rice cultivars mainly posses the genes, Xa1 and Xa3 for BB resistance. These resistance genes are becoming susceptible to K3a, new races of BB, resulting in the breakdown of resistance in high yielding Japonica cultivars. It is imperative to look for novel R-genes for improvement of japonica rice resistant to BB races. This study was carried out to conform useful single gene resistant to 24 BB isolates (including K3a, HB01009) breaking down Xa3 gene. Cultivars and near-isogenic lines (NILs) carrying Xa1, Xa2, xa8, Xa10, Xa11, xa13 genes were susceptible to 24 isolates, whereas IRBB4 carrying Xa4 gene was moderate resistance. IRBB5 and IRBB21 having xa5 and Xa21 genes, respectively, expressed resistance to these isolates. IRBB7 having Xa7 gene showed resistance response to 24 BB isolates, whereas JBB-107 carrying Xa7 gene was susceptible to 10 BB isolates and moderate resistant to 14 BB isolates. Xa7 gene showed different resistance response according to genetic background of used recurrent parent. With these findings, Xa4, xa5, and Xa21 would be the most prospective genes to 24 isolates used in screening.

We have discussed here the phenotypic and genetic characteristics as well as proteomic analysis of lesion mimic mutants (LLM) in rice. LLM is one of the mutants that induces cell death without infection of pathogen and produces defense signaling pathways. As the phenotypic expression, most LLMs induce spots on the leaf blades and leaf sheaths at their various developmental stages. We have discussed the nature of bl1, bl2, spl1, spl3, spl4, spl5 and spl6 LLMs in rice which were formed developmentally controlled spot on the leaf blades that were appeared as tiny dotted spots during tillering stage and gradually increased up to maturity. Through Northern blot analysis lower levels of rubisco large subunit and rubisco small subunit were observed in spotted leaves (sp) compared to non-spotted leaves (nsp). However, catalase was severely degraded in the sp. Broken thylakoid membranes of mesophyll chloroplasts were seen in nsp sections and were absent in sp sections of the mutant. Through 2-DE analysis 159 protein spots were differentially expressed between wild type and mutant from identified 800 reproducibleproteins, where 114 spots were up-regulated and 45 were down-regulated. Among quantified 25 protein spots, except two, all of the protein spots including protein disulfide isomerase, transketolase, thioredoxin peroxidase, ATP synthase, and rubisco large and small subunits were identified in the wild type but were absent in the mutant. However, catalase was up-regulated in the mutant. Genetic analysis indicated that studied bl1, bl2 and spl6 mutants are controlled by a single recessive gene.

It was practiced that crop rotation between barley and soybean to reduce the Barley yellow mosaic virus(BaYMV) in barley and investigated barley growth and yield. The diseased degree of barley by BaYMV reduced in one or two years fallow of barley with the soybean cultivated continuously in summer season. In the same practices, barley growth such as plant height and tiller number was better than another crop rotation plots. In yield components of barley, culm length and number of head was different among the treat plots. One or two years fallow of barley plots was better results than others. The yield of barley also showed significant difference in above one or two year fallow of barley. These plots showed higher yield from 24% to 32% than continuously cultivated barley and soybean plot. In comparison to conventional practice barley and rice, these rotation system presented higher barley yield from 3% to 13%. These crop rotations affect the density of the BaYMV vector, Polymyxa graminis. In these results, crop rotation with one or two years fallow of barley in viral infested paddy fields could reduce the BaYMV disease incidence and fungal vector density in soil.

Seedling establishment, winter survival rate and dry mater production of chinese milk vetch(Astragalus sinicus L.) in natural reseeding practice was compared with annual seeding during the period of 2006-2007. Generally, practicing natural reseeding technology gives higher seedling stand than the annual seeding because of high seeding survival rate. The high seedling survival rate in naturally reseeded plant is related to the longer root length than that of the annual-seeded plant. In annual seeding, most of seeds stayed on the soil surface and root can not easily penetrate the soil. However, in natural reseeding technology, the seeds are incorporated into the soil during land preparation and they emerged from the soil at 0 to 5cm depths, thereby it has longer root length. This long root length contributes to greater ability to survive even low temperature and low soil moisture condition during winter. The dry matter production in natural seeding was higher than the annual seeding at the early growth stage but the later it was similar in both natural reseeding and annual seeding.

The amount of salt to make seed sorting solution for rice of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18L water, which is lower amount than currently used. Various rice (Oryza sativa L.) cultivars were used to examine seed specific gravity effect on germination, seedling emergence, and early growth. Percent germination and seedling emergence were not different. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. As a result, it is considered that selecting seeds with water (larger than specific gravity of 1.00) instead of salt solution will not make large reduction in seedling emergence rate and have no effects in early growth.

Cadmium (Cd) is one of heavy metals that can be easily absorbed by plant roots, and transported from soil to shoots. The effect of Cd concentration (0~200 μM) on the physiological responses, Cd content of shoot and root, and antioxidant enzymes by oil plants Jatropha curcas (cv. Biji Jarak) were investigated in hydroponics system for two weeks. Stomatal conductance was significantly depressed by Cd treated plants. However, the leaf chlorophyll content was unaffected by Cd treated plants. Cd contents in the roots of Jatropha were accumulated higher than those of shoots. Jatropha treated plants at 100 and 200 μM was found to accumulate more than 100 mg kg-1 of Cd in shoots. Jatropha plants had a high ablity to uptake Cd from soil and transport it from soil to shoot as a Cd hyperaccumulator plant because of plants accumulating more than 100 mg kg-1 of Cd in shoots are considered to define as Cd hyperaccumulator. These results confirm that Jatropha is a suitable candidate for the phytoremediation of high-level cadmium contaminated soils.

This experiment was conducted to examine the influence of four plant growth regulators on growth, photosynthesis parameters and yield of soybean. To increase dry matter accumulation of seeds, some growth regulators were applied to field grown soybean cv. Sinpaldalkong #2 as determinate type and Muhankong as indeterminate type at dense planting condition. Choline caused significant reduction of stem length, but did not increase seed yield. The number of leaf and total leaf area were showed significant increase in all the treatments, but those increased tremendously in Muhankong treated with ethrel. CO2 assimilation and water use efficiency of a single leaf were showed the highest as 17.2 molm-2s-1 and 9.3 μ mmol mol-1 treated with mepiquat in Sinpaldalkong, respectively. The Photosynthetic rate was closely related to stomatal conductance, transpiration and water use efficiency. Mepiquat treatment mainly produced positive effects on the number of pods, percent of pod setting, number of seeds per pod in two cultivars and also increased their seed yield as compared with control.

인삼은 연작지 재배가 불가능하고 주산지의 우량 예정지 고갈로 인하여 제주도를 제외하고 국내 전국에서 재배하고 있다. 지역별 기후형태가 상이함에도 불구하고 동일한 해가림 구조로 재배하고 있어 일부지역에서 피해가 발생하고 있어 지역에 적합한 표준 해가림 재배기술이 필요하다고 생각된다. 따라서, 본 연구는 남부지역(밀양, 나주, 해남)에서의 적정 해가림구조를 밝히고자 실시하였다. 실험은 2008년 부산대학교 부속농장(밀양)에 묘삼을 이식하였고 해가림 시설은 차광망(검정 차광망), 차광판(비누수 광반사 차광판), 차광지+망(청색 비누수차광지에 검정색 차광망), 차광지(청색 비누수차광지)를 후주연결식으로 설치하여 삼집내 광량과 온도를 측정하였고(Li-cor사의 LI-2000) 광합성속도와 엽록소 형광반응은 생육하고 있는 2년생 인삼을 이용하여 Li-cor의 LI-6400으로 조사하였다. 해가림 자재별 광량은 차광판과 차광지에서 높은 경향을 보였으며, 차광판의 경우 전주에서의 반사광의 유입으로 삼집내 광량이 높은 경향이 있었고, 차광지의 경우 투광량이 높아 광량이 높게 나타냈다. 차광지+망과 차광망에서는 광량이 낮은 경향이었다. 온도는 차광판이 가장 낮은 경향이었는데 이는 직접광이 삼집내로 투과되지 못한 원인으로 사료되며, 다음으로 차광망, 차광지+망, 차광지 순으로 높은 경향을 보였다. 차광지의 경우 투광량이 높아 인삼에서 고온장해가 생기는 현상이 나타났다. 광합성의 경우, 광강도가 증가함에 따라 광합성속도가 증가하는 경향이 있었고, 해가림 자재에 따라 비교하면 차광판에서 높은 경향을 보였으며, 다음으로 차광망과 차광지+망이 높았고, 차광지에서 낮은 경향이었다. 엽록소 형광반응에서 Fo는 차광판에서 낮은 경향이었으며, 다음으로는 차광망, 차광지+망, 차광지 순으로 높은 경향을 보였다. Fv/Fm에서는 차광판에서 높았고, 차광망, 차광지+망, 차광지 순으로 낮은 경향이 있었다. ETR은 차광판에서 가장 높은 경향이 나타냈으며, 다음으로 차광망, 차광지+망, 차광지로 낮은 경향을 보였다.

This study was carried out to identify the quantitative trait loci (QTLs) for traits related to cold tolerance using an introgression lines (ILs) derived from a cross between a japonica weedy rice and a Tongil-type rice. Among the 80 RILs, one line (CR1835) showing tolerance for cold tolerance related to traits such as panicle exsertion and discoloration in the cold water plot was selected and backcrossed to the recurrent parent, Milyang 23. This line possessed Hapcheonaengmi 3 segments on chromosomes 1, 5 and 11. By two backcrosses to Milyang 23 and selfing, a total of 88 BC3F5 progenies were developed. The 88 ILs were evaluated for traits related to agricultural performance in cold water and in control plots. Cold tolerance was measured as difference of the culm length, spikelet fertility between two plots and panicle exsertion in cold water plot. The 88 ILs showed decreased culm length and increased anthocyan content in cold water plot than in the control water plot.

Awn, one of the domestication-related traits in rice might play an important role in seed dispersal. In a previous study, one major QTL, awn8 was detected on chromosome 8 using 120 RILs and 62 ILs derived from a cross between Hwayeongbyeo and O. rufipogon Griff. (Acc. W1944). We developed 140 BC1F3, 341 BC1F4 and 1533 BC1F5 plants from selfing of one plant selected from former generation. Each of selected plant was Hwayeongbeyo/W1944 heterozygous in the target region of chromosome 8. The Target marker(RM256) significantly linked to awn8 explained 60.3% of the total phenotypic variance in BC1F4 generations and the W1944 allele increased awn length. Using several substitution mapping, The awn8 QTL could be narrow down to the interval between RM23338-RM5485, with a distance of about 85.29kb. Total of ten genes were predicted in this region. At the same time, 34 BC3F5 lines were developed as the diverse NILs on chromosme 8. Using these NILs, One QTL for primary branch was detected in the target region and W1944 allele increased branch number. Characterization of the awn8 QTL would contribute the understanding of rice domestication and evolution and additional experiment would be need to be clarified whether awn8 and pb8 was due to linkage drag of independent genes or pleiotropic effect of the same gene.