인디카 벼는 일조시간이 짧은 열대지역에서 주로 재배하며, 자포니카 벼는 일조시간이 긴 한국, 일본, 및 중국(동북부 지역)을 포함하는 온대지역에서 재배한다. 최근 동남아 열대지역에서 자포니카 쌀에 대한 수요가 증가함에 따라 농촌진흥청은 필리핀 국제미작연구소(IRRI)와 공동으로 열대지역에 적응하는 다수성 온대 자포니카 벼 품종을 개발하고 있다. 일반적으로 자포니카 벼를 단일조건인 열대지역에 재배하면 이앙 후 바로 개화가 촉진되어 극조기 출수가 유도된다. 따라서 열대지역에 적응하는 자포니카 벼를 개발하기 위해서는 단일조건에서도 충분히 생장한 후 출수를 하는 특성이 우선적으로 필요하다. 본 연구는 국내 자포니카형 벼 품종인 ‘일품’과 미국에서 육성한 인디카형 벼인 ‘Zenith’를 교배한 F9 RIL 180 계통을 이용하여 필리핀의 단일조건하에서 재배하면서 출수기에 관련한 양적형질유전자좌(QTL) 분석을 수행한 바, 그 결과는 다음 과 같다. 1. 단일조건하에서 출수일수(파종~출수)에 관여하는 2종의 QTL(qHD6-SD와 qHD6-LD)을 탐색하였다. 2. 정밀지도제작 결과 qHD6-SD와 qHD6-LD은 모두 6번 염색체 Hd1 유전자를 포함하는 98 kb 영역에 존재하는 동일한 QTL인 것으로 나타났다 3. 시험계통을 필리핀 단일 조건에서 재배하였을 때 qHD6- SD 또는 qHD6-LD에서 Zenith allele형을 보유한 계통들은 일 품 allele형을 가진 계통들 보다 출수일수가 평균 8일 정도 길었다. 3. 시험계통을 한국의 장일 조건에서 재배하였을 때 qHD6- SD 또는 qHD6-LD에서 Zenith allele형을 보유한 계통들은 일품 allele형을 가진 계통들보다 출수일수가 평균 8일 정도 짧 았다. 4. 이러한 특성은 기존에 보고된 Hd1 유전자의 특성과 유사하여 qHD6-SD 및 qHD6-LD 은 Hd1 유전자일 가능성이 높은 것으로 나타났으며, 본 시험에서 사용한 Zenith는 nonfunctional Hd1 allele을 보유하는 것으로 추정되었다. 5. 이러한 결과를 통해 열대지역에 적응하는 자포니카 벼 육종연구에서 극조기 출수를 방지하고 충분한 출수일수를 확보하여 수량을 높이기 위해서는 인디카 벼가 주로 보유하고 있는 non-functional Hd1 allele을 반드시 도입해야 함을 재확인 하였다.
우리나라는 벼 재배를 위한 관개 시설이 비교적 잘 확보되어 염에 의한 피해가 적으나, 간척지를 비롯한 염 토양에서는 복합적 요인에 의해 벼 생육이 저해되므로 내염성 벼의 개발이 필요하다. 본 연구는 자포니카 벼로의 내염성 유전자 도입시 동반되는 열악형질을 최소화하기 위한 초정밀 분자표지 개발을 위해 기존에 보고된, Saltol QTL 분자표지의 이용 가능성을 검토하였다. 본 연구의 결과를 통해 1. 유묘 내염성 반복실험 및 정밀 검정을 통해 내염성이 안정적인 계통을 선발하였다. 2. HR28867/Pokkali와 조평/Saltol STL의 조합에서 SKC1 등 4 개(SKC1, RM10748, RM10793, RM7075)의 분자표지가 표현형과 유전자형이 일치하였으며, 분자표지 Pect4는 HR28867/ Pokkali의 조합에서만 일치하는 것으로 확인되었다. 본 연구의 결과는 자포니카 벼로의 내염성 유전자 도입에 필요한 초정밀 분자표지 개발의 기초 자료로 이용될 것이며, 향후 내염성 벼 육성을 통한 간척지 토지 이용 효율을 높이는 데 기여할 것으로 기대된다.
Pleurotus eryngii, an edible white-rot fungus, is cultivated widespread in Eurasia, northern Africa and China. It occupies the second position in the world mushroom market. Despites the importance, the small numbers of studies have been done. To promote the availability of P. eryngii, it is important to know the genome and organization of the fungus. In this study, the whole genome sequence of P5 monokaryon from P. eryngii KNR2312 strain was sequenced using Next Generation Sequencing (NGS) strategy. Identified 222 SSR markers based on newly known genome information and various type of markers used to construct the map consisted of 12 linkage groups (LGs) spanning 1047.8 cM. Using composite interval mapping, 71 quantitative trait loci (QTL)s were identified on 12 linkage groups (LG) for nine traits such as yield, quality, cap color and earliness in four different populations. Clusters of more than five QTLs for various traits were identified on three genomic regions on LG 1, 7, and 9. The largest cluster was identified on LG 1 in the range from 65.4 to 110.4 cM. We performed the genes prediction analysis responsible for yield in the LG1 genomic region with highest logarithm of the odd (LOD) scores The identified genes were involved in biomass degradation and synthesis and signal transduction. However, the region was wide to identifie the genes crucial role in important trait, we need to narrow down. To improve the resolution of QTL mapping, we enlarge the populations crossing with additional 205 monokaryons. Find mapping of QTLs will increases the accuracy and efficiency of interpret the genomic region and enhance the usefulness of genomic information. [Supported by a grant from the IPET (213007-05-1-SBI30), MIFAFF, Republic of Korea.]
The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an F2 intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left, right, and total) were measured in 1105 F2 progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1, 3, 7, 8, 10, 11, and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7, we identified a major QTL affecting total teat number that accounted for 5.6% of the phenotypic variance, which was the highest test statistic (F-ratio = 61.1 under the additive model, nominal P = 1.3×10-14) observed in this study. In this region, QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10, the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion, our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.
The objective of this study was to determine the response of QTL in each generation during selection to develop inbred lines. The simulation program was written in Fortran. Magnitude of QTL effects, base population size, number of QTL assigned to population, and the allelic frequency for the positive allele at each major QTL were highly associated with number of generations to fixation of QTLs during selection. Populations with larger QTL effects and larger base population size had more individuals with fixed QTL. However, a smaller number of QTL assigned to population had a higher fraction of individuals with fixed QTL at each generation compared with more populations with QTL. This simulation study will help to design biological experiments for detection of QTL-marker association using inbred population and to determine optimum number of lines with fixed QTL during inbred line development. To complement this study, additional simulation should be need with abundant replicates, more various population sizes, magnitude of QTL effects, and recombination between markers and QTLs.
요크셔종과 버크셔종 교배 실험 집단을 활용하여 양적형질 유전자좌 (QTL)의 발현 특성 관련 유전 양식을 조사하였다. 총 512두의 F 자손이 F간의 65교배 조합으로부터 생산되었으며 표현형 조사 기록은 일당증제량(ADG), 평균 등지방 두께(ABF), 10번째 등뼈 부위 등지방 두께(TRF) 및 등심단면적(LEA), 최후 척추부위 등지방 두께 (LRF)였다. 125종의 유전자 표지 (microsatellite)에 대한 3세대 개체별 유전자형이 분석되었
Molecular genetic markers were genotyped used to detect chromosomal regions which contain economically important traits such as growth traits in pigs. Three generation resource population was constructed from a cross between the Korean native boars and Landrace sows. A total of 193 F2 animals from intercross of F1 were produced. Phenotypic data on 7 traits, birth weight, body weight at 3, 5, 12, 30 weeks of age, live empty weight were collected for F2 animals. Animals including grandparents (F0), parents (F1), offspring (F2) were genotyped for 194 microsatellite markers covering from chromosome 1 to 18. Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. To characterize presence of imprinting, genetic full model in which dominance, additive and imprinting effect were included was fitted in this analysis. Significance thresholds were determined by permutation test. Using imprinting full model, four QTL with expression of imprinted effect were detected at 5% chromosome-wide significance level for growth traits on chromosome 1, 5, 7, 13, 14, and 16.
Rice production is largely affected by various environmental conditions such as cold, heat and flooding. Here, to identify cold tolerant QTLs at seedling stage in rice, we generated RIL population derived from a cross between Hanareum 2 and Unkwang which are a highly cold sensitive and cold tolerant, respectively. We observed cold phenotype of this population in the growth chamber conditions and natural field conditions. For observation of cold tolerant phenotype of RIL population in the growth chamber, we treated cold stress (5~13℃) for 14 days and recovery for 4 days. When we examined the phenotype of RIL in the field conditions, temperature range in the field conditions was about 6 to 25℃ in 2015~2016. We named QTLs as Seedling Cold Tolerant (SCT) in growth chamber and Cold induced Yellowing Tolerant (CYT) in the field, respectively. Three QTLs for SCT and 5 QTLs for CYT were detected on chromosome 1, 6, 7, 8, 10, 11 and 12. Among these QTLs, qSCT12 on chromosome 12 showed 26.3 LOD score with 25.5% of phenotypic variation. When qSCT11.1 and qSCT12 were combined, cold tolerant was most strongest in our experimental conditions. qCYT10 on chromosome 10 was identified in field experiment on both 2015 and 2016. These results may provide useful information for a marker-assisted breeding program to improve cold tolerance in rice.
Rice is the staple food of at least half of the world's population. Due to global warming, the weather is difficult to forecast nowadays. Therefore, it is necessary to breed various breeding to respond to such changes in the environment. This study was conducted to analyze the QTL about plant form, culm length, ear number and ear length by using 120 lines by anther culture, a cross between the Indica variety Cheongcheong and Japonica variety Nagdong. DNA marker was selected on the QTLs gene, and the following results were obtained. CNDH (Cheongcheong Nagdong Doubled Haploid) lines frequency distribution table curves about culm length, ear number and ear length exhibited showed a continuous variation close to a normal distribution. QTL analysis result, on culm length qPlL1-1 and qPlL1-2 were detected on the chromosome 1 and qPlL5 was detected on the chromosome 5. However, on ear length qPL2, qPL3 and qPL10, were detected on the chromosome 2, 3 and 10, while on ear number qPN1-1 and qPN1-2 were detected on the chromosome 1, qPN9 was detected on the chromosome 9. The QTLs related to culm length was found to chromosomes 5 and LOD scores were 3.81. The QTLs related to ear length was found to chromosomes 2 and 3 LOD scores were 7.13 and 3.20. The QTLs related to ear number was found to chromosome 9 and LOD scores were 4.27. Twenty two (22) Japonica cultivars and 12 Indica cultivars were analyzed polymorphisms, using selected 9 markers from the result about plant form analysis. RM5311, RM555 and RM8111 about the culm length, the ear length and number of ear were selected on the standard of Cheongcheong and Nagdong. Each rate of concordances about the culm length, the ear length and number of ear are 44.11%, 41.17% and 44.11%.
The rice recombinant inbred lines derived from Milyang23 and Gihobyeo cross were used in genetic mapping and QTL analysis studies. In this study, we developed a new 101 CAPS markers based on the SNPs in the whole genome region between these varieties. As a result, the total genetic distance and average distances were 1,696.97 cM and 3.64 cM, respectively. In comparison to the distance of the previous genetic map constructed based on 365 DNA markers, the new genetic map was found to have a decreased distance. The map was applied for the detection of QTLs on all seven traits relevant to diameter of stem internode, length of culms, length of panicles and the number of panicles including the correlation analysis between each trait. The QTLs results were similar to the report in previous studies, whereas the distance between the markers was narrowed and accuracy increased with the addition of 101 CAPS markers. A total of 9 new QTLs were detected for stem internode traits. Among them, qI1D-6 had higher LOD of 5.1 and phenotype variation of 50.92%. In this experiment, a molecular map was constructed with CAPS markers using next generation sequencing showing high accuracy for markers and QTLs. In the future, developing more accurate QTL information on stem internode diameters with various agriculturally important traits will be possible for further rice breeding.
Seed dormancy is an important adaptive mechanism to protect seeds under the unfavorable environments. Unlike to wild type species, the seed dormancy trait of cultivated crops has been weakened by breeding programs during the domestication period. Weak seed dormancy often causes preharvest sprouting (PHS) problem in many cereal crops that result in significant economic loss. The seed dormancy is a quantitative trait loci (QTL) controlled by multiple genetic and environmental factors. So far, many QTLs for seed dormancy have been identified from rice and wheat as well as in the model plant Arabidopsis. Unveiling of QTL genes and complex mechanisms underlying seed dormancy is accelerated by the rapid progress of crop genomics. In the present study, we reviewed current status of research progress on the seed dormancy QTLs and correlated genes in Arabidopsis and cereal crops.
Recently, many breeders have preferred to use molecular markers for introgression backcross programs enabling foreground and background selection to cope with rapid cultivar changing of seed markets. In accumulation of target traits with marker-assisted selection, larger numbers of markers should give better resolution. For the analysis of quantitative traits, a high-density genetic map with a large number of markers is required for discovering more accurately linked markers with traits. Watermelon is a recalcitrant plant to generate a high-density genetic map with conventional molecular markers including simple sequence repeats (SSRs), since watermelon has narrow genetic diversity background and severe segregation distortions of those SSR markers. Thus, we have developed efficient and valid way to assemble genetic map and markers by next-generation sequencing coupled with genotyping by sequencing in F2 generation. After crosses between Citurullus lanatus ssp. citroides (PI254744 and PI189225) and C. lanatus ssp. lanatus (TS34, Korean cultigen), 163 of F2 progeny were sequenced through Illumina's Hi-Seq GAII platform. From sequence information of those variant call files, the SNPs were indexed and filtered by sequencing depth with genotype converter (SNP Genotyper), and optimized by heuristic physical bin mapping to construct more reliable genetic linkage map. Reliable SNP loci were determined and compared to sequences of physical reference map. Using the genetic map, we determined QTLs in F2:3 population and found major loci corresponding to seed size and powdery mildew race1 resistance in watermelon.
고추의 적색소는 고추의 상품성을 가늠하는 중요한 척도이면서 식재료 뿐 아니라 상업적으로도 다양하게 활용되고 있다. 본 연구는 적색소 성분의 함량과 관계하는 QTL 마커를 개발하기 위하여 적색소 성분 분석을 위한 mapping 집단을 육성하였고, 적색소 성분에 대한 QTL mapping을 수행하였다. 적색소 분석을 위한 mapping 집단인 ‘만다린’과 ‘블랙클러스터’를 양친으로 하는 F7 RIL 집단에서의 색도(ASTA value) 분포는 1.64에서 117.26의 범주에 있으며 그 분포 양상은 정규분포를 보여 QTL분석에 적합한 것으로 확인되었다.Mapping 집단의 양친들에 대해서 454 GS-FLX pyrosequencing을 이용한 NGS를 수행하였고, 그 결과 ‘만다린’과 ‘블랙클러스터’각각 120.44Mb와 142.54Mb의 염기서열 데이터를 확보할 수 있었으며, ‘만다린’에서 1,025개, ‘블랙클러스터’에서 1,059개의 SNP들을 확보하게 되었다. 이 SNP들을 HRM 분석에 용이하도록 프라이머를 제작하여 유전자 지도 작성을 수행한 결과 총 246개의 SNP 마커를 이용하여 약 512cM을 설명할 수 있는 21개 연관군의 유전자 지도가 작성되었다. 분석 집단 93계통들에서 측정된 ASTA 값을 이용하여 수행한 QTL 분석 결과 총 6개의 QTL 을 확인하였다. 이들 QTL과 근접한 마커들은 향후 고추의 적색소 함량 연구에 매우 유용한 정보로 활용될 것이며, 아직까지 개발된 바 없는 적색소 함량 연관 마커 개발에 가능성을 열어줄 것으로 기대한다.
아열대 및 온대지역에서 주로 발생하는 애멸구는 5월∼8월 사이 편서풍을 타고 우리나라에 비례하며 벼 바이러스병인 줄무늬잎마름병을 매개한다. 줄무늬잎마름병은 벼의 수량감소와 미질을 떨어뜨리는 주요 병해 중 하나이다. 애멸구와 같은 멸구류는 대부분 살충제에 의해 방제를 하고 있으나 이러한 약제의 계속된 사용은 환경오염과 약제저항성 개체의 발생을 유발시킬 수 있는 큰 단점이 있다. 이와 같이 벼에 심각한 피해를 입히는 병해충에 대한 저항성 품종 육성은 병해충을 방제하는 가장 경제적이고 효과적인 방법으로 알려져 있다. 줄무늬잎마름병의 저항성 관련 유전자는 ‘Modan’에서 유래한 Stv-bi, 일본 밭벼 또는 열대 자포니카 품종에서 유래한 Stv-a, Stv-b가 알려져 있으며, 국내에서는 주로 Stv-bi가 도입된 저항성 품종들이 육성되고 있다. 단일 유전자를 이용한 저항성 품종육성은 새로운 바이러스의 등장에 취약하므로 저항성 유전자원의 다양화와 새로운 유전자의 탐색이 필요하다. 본 실험 에서는 Stv-a 와 Stv-b가 보고된 USA 품종인 Zenith의 형질을 일품에 도입하여 180계통의 F2 집단을 육성하여 생물검정과 함께 QTL분석에 이용하였다. 줄무늬 잎마름병에 대한 Zenith에 대한 QTL을 탐색한 결과, 11번 염색체에서 LOD 11.9, 설명가능한 표현형 변이 27%인 QTL이 확인되었다. 줄무늬 잎마름병 연관 QTL 및 이와 관련된 marker는 향후 줄무늬잎마름병에 대한 새로운 저항성 유전자인 Stv-b를 보유하는 품종육성을 위한 MAS 체계 확립에 이용할 것이다.
Understanding how crops interact with their environments is increasingly important in breeding program, especially in light of highly anticipated climate changes. A total of 150 recombinant inbred lines (RILs) of F12 generation derived from Dasanbyeo (Indica) x TR22183 (Japonica) were evaluated at Suwon 2010, Shanghai 2010, IRRI 2010 wet season, Suwon 2011, Shanghai 2011, IRRI 2011 dry season, and IRRI 2011 wet season as a total of seven diverse environments. Traits evaluation included eight important agronomical traits such as days to heading (DTH), culm length (CL), panicle length (PL), panicle number per plant (PN), spikelet number per panicle (SN), spikelet fertility (SF), 100-grain weight (GW), and grain yield (GY). As a result of genotyping using 384-plex GoldenGate oligo pool assay (OPA) set (RiceOPA3.1), the linkage map for 235 SNP markers covering a total of 926.53 cM with an average interval of 4.01 cM was constructed and a total of 44 main-effect quantitative trait loci (QTL)s and 35 QTLs by environment interaction (QEI) were detected for all eight traits using single environment and multi-environments analysis, respectively. Of these, fourteen putative QTLs for DTH, CL, PN, SN, GW and GY found in single environment analysis had the similar position to QEI for those traits, suggesting that these same QTLs from both single-and multi-environments are major and stable for certain traits. To the best of our knowledge, 12 QTLs consisted of four QTLs for CL (qCL2, qCL8.1, qCL8.2, and qCL8.3), six QTLs for GW (qGW3.1, qGW3.2, qGW7, qGW8, qGW10.1, and qGW10.2), one QTL for GY (qGY3) and one for SF (qSF4) out of 44 QTLs obtained from single environment analysis were considered to be novel since no overlapping QTL was reported from previous studies. In addition, 12 out of 35 QTLs obtained from multi-environments analysis were also novel.