• Molecules and Cells
• /
• 제37권2호
• /
• pp.149-160
• /
• 2014

Plant breeders have focused on improving plant architecture as an effective means to increase crop yield. Here, we identify the main-effect quantitative trait loci (QTLs) for plant shape-related traits in rice (Oryza sativa) and find candidate genes by applying whole genome re-sequencing of two parental cultivars using next-generation sequencing. To identify QTLs influencing plant shape, we analyzed six traits: plant height, tiller number, panicle diameter, panicle length, flag leaf length, and flag leaf width. We performed QTL analysis with 178 $F_7$ recombinant inbred lines (RILs) from a cross of japonica rice line 'SNU-SG1' and indica rice line 'Milyang23'. Using 131 molecular markers, including 28 insertion/deletion markers, we identified 11 main- and 16 minor-effect QTLs for the six traits with a threshold LOD value > 2.8. Our sequence analysis identified fifty-four candidate genes for the main-effect QTLs. By further comparison of coding sequences and meta-expression profiles between japonica and indica rice varieties, we finally chose 15 strong candidate genes for the 11 main-effect QTLs. Our study shows that the whole-genome sequence data substantially enhanced the efficiency of polymorphic marker development for QTL fine-mapping and the identification of possible candidate genes. This yields useful genetic resources for breeding high-yielding rice cultivars with improved plant architecture.

• Plant Biotechnology Reports
• /
• 제4권1호
• /
• pp.23-27
• /
• 2010

Quantitative trait loci (QTLs) controlling ability of somatic embryogenesis were identified in soybean. A frame map with 204-point markers was developed using an RI population consisting of 117 $F_{11}$ lines derived from a cross between cultivar 'Keburi' and a weedy soybean 'Masshokutou Kou 502'. The parents differed greatly in their abilities of somatic embryogenesis using immature cotyledons as explants. The ability of somatic embryogenesis was evaluated in five different experiments: the $F_{11}$ (evaluated in 1998) and $F_{15}$ (2002) generations cultured on basal media supplemented with $40\;mg\;l^{-1}$ 2,4-D (2,4-D1998 and 2,4-D2002), $F_{14}$ (2001) generation on medium with $40\;mg\;l^{-1}$ 2,4-D and high sucrose concentration [2,4-D2001 ($30\;g\;l^{-1}$ sucrose)], and the $F_{11}$ (1998) and $F_{12}$ (1999) generations on medium with $10\;mg\;l^{-1}$ NAA (NAA1998 and NAA1999). The RILs showed wide and continuous variations in each of the five experiments. In the composite interval mapping analysis, 2 QTLs were found in group 8 (D1b + W, LOD = 5.42, $r^2$ = 37.5) in the experiment of 2,4-D1998 and in group 6 (C2, LOD = 6.03, $r^2$ = 26.0) in the experiment of 2,4-D2001 (high concentration sucrose). In both QTLs, alleles of 'Masshokutou Kou 502' with high ability of somatic embryogenesis contributed to the QTLs. For the other three experiments, no QTL was detected in the criteria of LOD >3.0, suggesting the presence of minor genes.

• Journal of Crop Science and Biotechnology
• /
• 제11권4호
• /
• pp.243-248
• /
• 2008

The bean bug Riptortus clavatus Thunberg (Heteroptera: Alydidae) is an important pest, causing serious yield loss in soybean. But the information on mechanism of resistance to R. clavatus is limited. The objective of this study was to identify QTLs for R. clavatus resistance using simple sequence repeat (SSR) markers in a soybean population of recombinant inbred lines (RILs) developed from the cross PI 171451 ${\times}$ Hwaeomputkong. A genetic map from this population was constructed with a total of 136 SSR markers covering 1073.9 cM on 20 linkage groups (LGs). With 126 $F_5$ RILs, two independent QTLs for resistance to R. clavatus were mapped on LGs B1 and C2. The amount of phenotypic variation explained by these QTLs ranged from 12 to 16%. PI 171451 showed an escape response to R. clavatus. Under feeding conditions, 14.4% of RILs showed greater resistance to R. clavatus than the resistant parent. The resistance to R. clavatus in soybean from PI 171451 was incomplete and quantitatively inherited and the QTLs for resistance to R. clavatus detected in the RIL population were not significantly affected by epistatic interactions.

• 한국육종학회지
• /
• 제41권4호
• /
• pp.429-436
• /
• 2009

We conducted a QTL analysis of grain quality traits using 117 $BC_3F_4$ and $BC_3F_5$ lines developed from a cross between Ilpumbyeo and Moroberekan. Genotypes of 117 $BC_3F_5$ lines were determined using 134 simple sequence repeat (SSR) markers. A linkage map constructed using 134 SSR markers was employed to characterize quantitative trait loci (QTL). The 117 $BC_3F_4$ and $BC_3F_5$ lines were evaluated for eleven grain quality traits in 2005 and 2006. A total of 18 QTLs were identified for eleven traits, and the phenotypic variance explained by each QTL ranged from 9.9% to 35.2%. Moroberekan alleles contributed positive effects in the Ilpumbyeo background at two QTL loci for 1,000 grain weight. Four QTLs, two for chalky rice and one each for 1,000 grain weight and head rice were consistently detected in two consecutive years indicating that these QTLs are stable. Clusters of QTLs were observed in three chromosome regions. One cluster harboring five QTLs including head rice and brown rice ratio near SSR markers RM190 and RM314 was detected on chromosome 6. Another cluster harboring grain weight and white belly was detected on chromosome 2. Increase in white belly at this locus might be due to the increase in grain weight due to the presence of the Moroberekan allele. The Moroberekan alleles at two QTL loci, gw3 and gw4 associated with increased grain weight might be useful in breeding programs to develop high-yielding cultivars.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.201-201
• /
• 2022

Rice bakanae disease is a serious global threat in major rice-cultivating regions worldwide causing high yield loss. It is caused by the fungal pathogen Fusarium fujikuroi. Varying degree of resistance or susceptibility to bakanae disease had been reported among Korean japonica rice varieties. We developed a modified in vitro bakanae disease bioassay method and tested 31 Korean japonica rice varieties. Nampyeong and Samgwang varieties showed highest resistance while 14 varieties including Junam and Hopum were highly susceptible with 100% mortality rate. We carried out mapping QTLs for bakanae disease resistance with four F2:F3 populations derived from the crosses between Korean japonica rice varieties. The Kompetitive Allele-Specific PCR (KASP) markers developed in our laboratory based on the SNPs detected in Korean japonica rice varieties were used in genotyping F2 plants in the populations. We found four major QTLs on chromosome 1, 4, 6, and 9 with LOD scores of 21.4, 6.9, 6.0, and 60.3, respectively. In addition, we are doing map-based cloning of the QTLs on chromosome 1 and 9 which were found with Junam/Nampyeong F2:F3 population and Junam/Samgwang F2:F3 population, respectively. These QTLs will be very useful in developing bakanae disease resistant high quality rice varieties.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권8호
• /
• pp.1062-1066
• /
• 2001

Studies were carried out on forty young bulls of the Hariana breed (around 18 months of age) selected on the basis of their dam's milk yield at the animal farm of CCS HAU, Hisar during the period 1993-1999. Since animals showed variation in capacity to work over prolonged periods, they were subjected to regimes of carting without load and with 8 qtls. of load for three hours. The study revealed that maximum change took place in the pulse rate, followed by respiration rate and rectal temperature. The mean fatigue score for pulling an empty cart ranged between 1.66 to 2.20 after two hours work, and 2.36 to 2.73 after three hours work. For a cart loaded with 8 qtls., the corresponding ranges were 2.90 to 3.36 and 3.40 to 4.10, respectively. These results indicated that the animals under experiment had the capacity to pull moderate load (8 qtls.) for about two hours without showing any serious effect on the ability to recover and soon to work again.

• 생명과학회지
• /
• 제20권8호
• /
• pp.1186-1192
• /
• 2010

콩은 세계 유지작물시장에서 48%을 차지하는 중요한 작물이다. 콩 종실의 크기와 기름함량의 양적 및 질적 개선이 콩 육종에 있어서 가장 중요한 목적중의 하나이다. 이 연구의 목적은 종실의 크기와 지방산조성을 조절하는 양적 형질 유전자좌를 밝히는 것이다. 큰올콩과 익산10호의 교배로부터 F2:10 세대의 재조합자식계통 115계통을 이용하였다. 협의 유전력 검정에서는 백립중이 0.72, 포화지방산(팔미트산 + 스테아릭산)이 0.60, 올레익산이 0.83과 리놀레익산이 0.77 및 리놀렌산이 0.81을 나타내었다. 백립중과 연관된 양적형질유전자좌는 염색체 1번, 3번, 8번, 9번과 16번 및 17번에 7개로 나타났다. 포화지방산은 염색체 17번과 19번에 2개의 독립된 양적 형질 유전자좌가 연관되어 있었다. 올레익산 함량에 대해서는 다섯 개의 독립적인 양적 형질 유전자좌가 염색체 7번, 11번, 14번과 16번 및 19번에서 확인하였다. 리놀레익산 함량에 대한 5개의 양적 형질 유전자좌는 염색체 2번, 11번, 14번과 16번 및 19번에 있었다. 리놀렌산 함량은 3개의 양적형질유전자좌가 염색체 8번과 10번 및 19번에 관련되어 있었다. 그리고 올레익산과, 리놀레익산 및 리놀렌산에 공통적으로 확인되는 주요 양적 형질 유전자좌는 염색체 19번 이었다.

• 생명과학회지
• /
• 제14권5호
• /
• pp.821-828
• /
• 2004

엽면적과 엽장 및 엽폭은 식물의 광합성 효율과 관련이 있다. 단위 엽면적당 광합성율을 증가는 콩에서 종실 수량을 증가시킨다 따라서 본 연구는 큰올콩과 신팔달콩 및 익산10호를 각각 교배하여 얻은 두 집단이 잎의 엽장과 엽폭 및 장폭비를 확인할 수 있는 SSR 마커를 선발하기 위하여 실시하였다. 잎의 장폭비는 두 집단에서 엽폭과 유의적인 부의 상관을 보였다. 엽장은 큰올콩/신팔달롱 조합에서 연관군 DIb+W와 L에서 두개의 작은 양적 형 질 유전자좌 (QTL)를 탐색하였으며, 큰올콩/익산10호 조합에서는 연관군 1와 L에서 두개 의 양적 형 질 유전자좌가 관련하였다. 엽폭은 큰올콩/신팔달콩 조합에서 2개, 큰올콩/익산10호 조합에서 3개의 양적형질 유전자좌가 관련하였으며 이들은 각각 전체 형질 변이의 13% 및 18.04%를 설명할 수 있었다. 장폭비는 큰올콩/신팔달콩 조합에서 연관군 I와 L에서 2개, 큰올콩/익산10호 조합에서 연관군 Cl과 E 및 L에서 3개의 양적형질 유전자좌가 관련하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제29권1호
• /
• pp.43-50
• /
• 2016

Quantitative trait locus (QTL) is a particular region of the genome containing one or more genes associated with economically important quantitative traits. This study was conducted to identify QTL regions for body weight and growth traits in purebred Korean native chicken (KNC). F1 samples (n = 595) were genotyped using 127 microsatellite markers and 8 single nucleotide polymorphisms that covered 2,616.1 centi Morgan (cM) of map length for 26 autosomal linkage groups. Body weight traits were measured every 2 weeks from hatch to 20 weeks of age. Weight of half carcass was also collected together with growth rate. A multipoint variance component linkage approach was used to identify QTLs for the body weight traits. Two significant QTLs for growth were identified on chicken chromosome 3 (GGA3) for growth 16 to18 weeks (logarithm of the odds [LOD] = 3.24, Nominal p value = 0.0001) and GGA4 for growth 6 to 8 weeks (LOD = 2.88, Nominal p value = 0.0003). Additionally, one significant QTL and three suggestive QTLs were detected for body weight traits in KNC; significant QTL for body weight at 4 weeks (LOD = 2.52, nominal p value = 0.0007) and suggestive QTL for 8 weeks (LOD = 1.96, Nominal p value = 0.0027) were detected on GGA4; QTLs were also detected for two different body weight traits: body weight at 16 weeks on GGA3 and body weight at 18 weeks on GGA19. Additionally, two suggestive QTLs for carcass weight were detected at 0 and 70 cM on GGA19. In conclusion, the current study identified several significant and suggestive QTLs that affect growth related traits in a unique resource pedigree in purebred KNC. This information will contribute to improving the body weight traits in native chicken breeds, especially for the Asian native chicken breeds.

• 한국육종학회지
• /
• 제40권4호
• /
• pp.414-421
• /
• 2008

We conducted a QTL analysis of agronomic traits using 117 $BC_3F_5$ and $BC_3F_6$ lines developed from a cross between Ilpumbyeo and Moroberekan. Genotypes of 117 $BC_3F_5$ lines were determined using 134 simple sequence repeat (SSR) markers. A total of 832 Moroberekan chromosome segments with 410 homozygous and 422 heterozygous, respectively, were detected, and the genetic distance of introgression segments ranged from 0.5 cm to 112.1 cm. A linkage map constructed using 134 SSR markers was employed to characterize quantitative trait loci (QTL). The 117 $BC_3F_5$ and $BC_3F_6$ lines were evaluated for seven agronomic traits at two locations in 2006 and 2007 and at one location in 2007. A total of 26 QTLs were identified for seven traits including days to heading, and the phenotypic variance explained by each QTL ranged from 9.2% to 24.2%. Moroberekan alleles contributed positive effects in the Ilpumbyeo background at eleven QTL loci including panicle length and spikelets per panicle. Five QTLs, two for days to heading and one each for culm length, panicle length and spikelets per panicle were consistently detected in every occasions indicating that these QTLs are stable. Among them, two QTLs, spp6 for spikelets per panicle and pl6 for paniclel length were localized in the similar region. Increase in spikelets per panicle at this locus might be due to the increase in panicle length, because both traits were associated with increase in spikelets per panicle and panicle length due to the presence of the Moroberekan allele. These Moroberekan QTLs might be useful in breeding programs to develop high-yielding cultivars.