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.
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.
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.
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.
The lorry based transportation system in korea has many problems such as high domestic logistic cost, environment pollution and road damage etc. Hereupon, the necessity of improvement for national logistics system has been proposed continuously. Therefore we carried out this research through AHP(Analytic Hierarchy Process) to measure relative importance between effect factors and constraint factors and examined the possibility of Modal Shift from lorry transportation to coastal transportation. As the results of this research, the relative priority on modal shift policy enforcement (0.556) is higher than that of maintenance of the present transportation system(0.444).
In the previous study, 141 BC3F2 lines from a cross between the Oryza sativa cv. Milyang 23 and O. glaberrima were used to identify favorable wild QTL alleles for yield component traits. In this study, we carried out QTL analysis of four grain morphology as well as four yield component traits using 141 BC3F5 lines from the same cross and compared QTLs detected in two different generations. The mean number of O. glaberrima segments in the 141 BC3F5 lines ranged from 1 to 13 with 2.69 and 5.71 of the average means of homozygous and heterozygous segments, respectively. There was a three-fold difference in the number of QTLs detected for four traits commonly evaluated in two generations (seven QTLs in the BC3F5 vs 21 in the BC3F2 population). The percentages of the phenotypic variance explained by QTLs in the BC3F5 population were similar to or less than those in the BC3F2 population. This is probably due to the difference in the genetic composition of two populations and the environmental effects. The locations of the QTLs commonly detected in both generations were in good agreement except for one QTL for spikelets per panicle. The yield QTL, yd3 was colocalized with the spikelets per panicle, spp3. Yield increase at this locus is due to the increase in spikelets per panicle, because both traits were associated with increase in spikelets per panicle and yield due to the presence of an O. glaberrima allele. Clusters of QTLs for grain morphology traits were observed in two chromosome regions. One cluster harboring five QTLs near SSR markers RM106 and RM263 was detected on chromosome 2. This population would serve as a foundation for development of the introgression line population from a cross between Milyang 23 and O. glaberrima.
This study was carried out to get the genetic information on the germination rate and fat acidity after 12 weeks’storage at 35 . Germination rate decreased with longer storage period, ℃ while fat acidity increased. Germination rate was higher in the order of Koshihikari, Hanmaeum and Unkwangbyeo after 12 weeks’storage at 35℃. Fat acidity of Koshihikari and Hanmaeum was gradually increased, but that of Unkwangbyeo was dramatically increased after 4 weeks’storage at 35℃. The genetic mode on germination rate and fat acidity using the joint scaling test was shown to be additive-dominance gene effects. Additive([d]) effect was higher than dominance effect([h]) in all crosses. The average degree of dominance, [h]/[d], was less than 1, indicating that germination rate and fat acidity was partially dominant. Germination rate and fat acidity based on frequency distribution of 2 crosses were quantitative characters expressed by polygenes.
In rice, tillering is an important trait determining yield. To study tillering at the agricultural and molecular aspects, we have examined a spontaneous rice mutant that showed reduction in the number of culms. The mutant was derived from a F6 line of the cross of Junambyeo*4 / IR72. It could produce, on average, 4 tillers per hill in the paddy field while wild-type plants usually have 15. Except the reduced culm numbers, they also show pale green phenotypes. The phenotypes of this mutant were co-segregated as the monogenic Mendelian ratio (χ2 = 0.002, p = 0.969). In order to locate a gene responsible for the rcn phenotype, the mutant with the japonica genetic background was crossed with Milyang21 of the indica background. Bulked segregant analysis was used for rapid determination of chromosomal location. Three SSR markers (RM551, RM8213, and RM16467) on chromosome 4 were genetically associated with the mutant phenotype. Each of the 217 F2 plants was genotyped with simple sequence length polymorphisms. The data showed that RM16572 on chromosome 4 was the closest marker that showed perfect co-segregation among the F2 population. We suggest the new rcn gene studied here name as rcn10t because there was no report which exhibit a rcn phenotype with a pleiotropic effect of pale green (chlorophyll deficiency), and mapped at same position on chromosome 4.
Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.
With the development of diverse agricultures worldwide, biofortified rice noted for its preferable marketability and palatability plays an important role in the world's agricultural economics and rice breeding programs. In this report, several M5 of T-DNA inserted lines derived from the donor cultivars, 'Hwayong' and 'Dongjin', were selected for high or low protein, high lipid and low amylose content, respectively. The coefficients and ranges of variation for the chemical constituents between M4 and M5 T-DNA inserted lines were evaluated in comparison with those of the donor varieties. Results indicated that T-DNA insertion might be an effective way to generate useful variations for chemical composition of rice grains which could be used for the development of biofortified rice cultivars.