• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.248-255
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• 2021

This study was conducted to obtain basal information for the development of perilla cultivars with improved quality. The F₇ population of recombinant inbred lines (RILs) from a cross between the parents of Daesil for seeds and Ipdeulkkae1 for vegetables was used as the material. We evaluated several agricultural characteristics and seed quality. Variations were observed in most of the measurements; for example, stem length (ranging from 66.0 to 150.0 cm), number of branches (from 5 to 23), flower cluster length (ranging from 5.1 to 10.5 cm), number of flower clusters (from 17 to 131), a-linolenic acid content (from 54.2 to 64.1%), and functional compound content (rosmarinic acid 869.5~3,508.1 ㎍/g; luteolin 47.4~864.3 ㎍/g; apigenin 57.1~296.7 ㎍/g) all showed variation. Significant correlations between stem length and the number of branches (0.561) and number of branches versus number of flower clusters (0.638) were detected in the RIL F₇ population. Most agricultural characteristics and seed qualities showed a normal distribution with large variation, and transgressive segregation was observed in many descendants with characteristics to those of their parents. Daesil/Ipdeulkkae1 RIL F₇ populations could be useful for future QTL analysis as well as for intermediate breeding lines for high-quality perilla cultivars.

• Molecules and Cells
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• v.21 no.2
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• pp.192-196
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• 2006

Salt tolerance was evaluated at the young seedling stage of rice (Oryza sativa L.) using recombinant inbred lines (MG RILs) from a cross between Milyang 23 (japonica/indica) and Gihobyeo (japonica). 22 of 164 MG RILs were classified as tolerant with visual scores of 3.5-5.0 in 0.7% NaCl. Interval mapping of QTLs related to salt tolerance was conducted on the basis of the visual scores at the young seedling stage. Two QTLs, qST1 and qST3, conferring salt tolerance, were detected on chromosome 1 and 3, respectively, and the total phenotypic variance explained by the two QTLs was 36.9% in the MG RIL population. qST1 was the major QTL explaining 27.8% of the total phenotypic variation. qST1 was flanked by Est12~RZ569A, and qST3 was flanked by RG179~RZ596. The detection of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salt tolerance.

• Journal of the Korean Society of International Agriculture
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• v.31 no.4
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• pp.428-436
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• 2019

As the main objective of rice breeding programs, rice eating quality is one of critical factors directly determining the market price and the consumer preference. However, the genetic complexity of eating quality and the difficulty in accurate evaluation often constrain improvement of the eating quality in rice breeding programs. In addition, given that the rice eating quality of current cultivars has already reached some high-level, diversifying of genetic resources are demanded more than ever to improve the rice eating quality. In this study, we developed a recombinant inbred lines (RILs) population derive from Wandoaengmi6, a japonica-type Korean weedy rice with high eating quality and a high degree of glossiness of cooked rice. Year-to-year correlations between the traits in three years were shown normal distribution for major agronomic traits and physicochemical characteristics. After evaluating tested traits related to eating quality procedure, a total of ten lines were ultimately selected from the population. Increasement of the taste of cooked rice (TA) and the overall eating quality (OE) were confirmed in the selected lines, which are caused by alleles derived from Wandoaengmi6 without any linkage drag. These results indicate that the utility of wide genomic resources in Korean landrace could be of application in various rice breeding programs and countermeasure to contribute to properly response to climate change.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.134-146
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• 2023

Phytophthora root rot (PRR) is a major soybean disease caused by an oomycete, Phytophthora sojae. PRR can be severe in poorly drained fields or wet soils. The disease management primarily relies on resistance genes called Rps (resistance to P. sojae). This study aimed to identify resistance loci associated with resistance to P. sojae isolate 40468 in Daepung × CheonAl recombinant inbred line (RIL) population. CheonAl is resistant to the isolate, while Daepung is generally susceptible. We genotyped the parents and RIL population via high-throughput single nucleotide polymorphism genotyping and constructed a set of genetic maps. The presence or absence of resistance to P. sojae was evaluated via hypocotyl inoculation technique, and phenotypic distribution fit to a ratio of 1:1 (R:S) (χ² = 0.57, p = 0.75), indicating single gene mediated inheritance. Single-marker association and the linkage analysis identified a highly significant genomic region of 55.9~56.4 megabase pairs on chromosome 18 that explained ~98% of phenotypic variance. Many previous studies have reported several Rps genes in this region, and also it contains nine genes that are annotated to code leucine-rich repeat or serine/threonine kinase within the approximate 500 kilobase pairs interval based on the reference genome database. CheonAl is the first domestic soybean genotype characterized for resistance against P. sojae isolate 40468. Therefore, CheonAl could be a valuable genetic source for breeding resistance to P. sojae.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.236-236
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• 2022

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.85-92
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• 2008

An RIL population from a Shinpaldalkong2/GC83006 cross was employed to identify quantitative trait loci (QTL) associated with agronomic traits in soybean. The genetic map consisted of 127 loci which covered about 3,000cM and were assigned into 20 linkage groups. Phenotypic data were collected for the following traits; plant height, leaf area, flowering time, pubescence color, seed coat color and hilum color in 2005. Seed weight was evaluated using seeds collected in 2003 to 2005 at Suwon and in 2005 at Pyeongchang and Miryang sites. Three QTLs were associated with 100-seed weight in the combined analysis across three years. Among the three QTLs related to seed weight, all GC83006 alleles on LG O ($R^2\;=\;12.5$), LG A1 ($R^2\;=\;10.1$) and LG C2 ($R^2\;=\;11.5$) increased the seed weight. A QTL conditioning plant height was linked to markers including Satt134 (LG C2, $R^2\;=\;25.4$), and the GC83006 allele increased plant height at this QTL locus. For two QTLs related to leaf area, 1aM on LG M ($R^2\;=\;10.0$) and laL on LG L ($R^2\;=\;8.6$), the Shinpaldalkong2 alleles had positive effect to increase the leaf area. Satt134 on LG C2 ($R^2\;=\;41.0$) was associated with QTL for days to flowering. Satt134 (LG C2) showed a linkage to a gene for pubescence color. Satt363 (LG C2) and Satt354 (LG I) were linked to the hilum color gene, and Sat077 (LG D1a) was linked to the seed coat color. The QTL conditioning plant height was in the similar genomic location as the QTLs for days to flowering in this population, indicating pleiotropic effect of one gene or the tight linkage of several genes. These linked markers would be useful in marker assisted selection for these traits in a soybean breeding program.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.243-248
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• 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.

• Journal of Life Science
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• v.14 no.2
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• pp.339-344
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• 2004

Identification of individual quantitative trait loci (QTL) is a prerequisite to application of marker-assisted selection for stern length. Two simple sequence repeat (SSR)-based linkage maps were constructed from recombination inbred line populations between cross of Keunolkong and Shinpaldalkong. Two parents used differed greatly in stem length, which were 30.57 cm and 49.75 cm in Keunolkong and Shinpaldalkong, respectively. Using the constructed maps, regression analysis and interval mapping were performed to identify QTLs conferring stem length. Four QTLs for stem length on linkage groups (LG) F, J, N and O were identified in the Keunolkong ${\times}$ Shinpaldalkong population and they totally explained 37.83% of variation for stem length. In the population, two major QTLs on LG J and O conditioning 14.25% and 10.68% of the phenotypic variation in stem length were determined and two QTLs with minor effect were detected on LG F and N. Identification of QTLs for stem length and mapping individual locus should facilitate to describe genetic mechanisms for stem length in different population. SSR markers tightly linked to QTLs for stem length allow to accelerate the elimination of deleterious genes and selection for desirable recombinants at early stage in crop breeding programs.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.23-27
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• 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.

• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.48-53
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• 2008

This study presents a case study designed to compare the selection efficiency between phenotypic selection (PS) and marker-assisted selection (MAS) in breeding of resistance lines to brown planthopper (BPH). The efficiency between PS and MAS were compared with four population such as the $F_2$, RILs ($F_6$), DH, and backcrosse ($BC_6F_5$) population, derived from a cross 'Samgang / Nagdong'. The resistance lines were selected using two markers, RM28493 and BpE18-3, related to BPH resistance were screened as resistance lines over 95% in PS. The costs required for BPH screening in the MAS system account for approximately 32% of the total costs of PS. The period needed to select the resistance plants was 30 days in PS and 7 days in MAS. Based on the results, we could establish the breeding system for selection of BPH resistance lines by MAS.