• Korean journal of applied entomology
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• v.58 no.4
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• pp.305-311
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• 2019

Artificial interspecific matings between Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) were conducted to know the possibility of hybridization of the two sympatric species. Reciprocal crossings successfully produced F1 hybrids. Most of F2 crosses yielded progenies except all mating trials with females of F1 hybrid obtained from M. phaseoli female. Inbreedings of the F2 hybrids produced F3 progenies. In backcrossings between F1 hybrids and parent lines, all the two mating trials with females of F1 hybrid obtained from M. phaseoli females did not produce any progeny, while other 6 backcrosses produced the next generations. Inbreedings of the backcross lines also produced subsequent progenies. These results indicated that F1 females produced from hybridization between M. phaseoli females and M. falcana males were sterile. Conclusively, it suggested that a partial reproductive isolation at a postzygotic stage can occur between the two sympatric species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.2
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• pp.165-170
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• 1990

In order to determine the relationship between dwarf gene and GA$_3$ response, three dwarf cultivars, Fukei 71, Seolak, and Tanginbozu, which were known to have d 50, d 47 and d 35 gene, respectively, were used as parents in this study. Three parents and their F$_1$ and F$_2$ generations were grown. Tillers of each plant were devided into two parts at 15 days after transplanting and was transplanted. One part of them was sprayed with GA$_3$ 50 ppm at booting stage. The internode length were measured at ripening stage in terms of GA$_3$ response. The internode was significantly elongated in Seolak and Tanginbozu, but not in Fukei 71. All F$_1$ plants of the crosses were tall, and their internode and culm were significantly elongated with the spraying of GA$_3$. Dwarf plants which are not responded to GA$_3$ were selected in the F$_2$'s of Seolak/Fukei 71 and Fukei 71/Tanginbozu crosses, and backcrossed to Fukei 71. All of these BC$_1$F$_1$ plants were uniform in the culm length and not responded to GA$_3$ treatment. The dwarf gene, d 50 of Fukei 71 seems to be closely associated with the facter of non-response to GA$_3$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.413-417
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• 1993

This study was conducted to breed various cytoplasmic genetic male sterile (CGMS) and restorer lines with backgrounds of Korean japonica rice varieties. The CGMS line BT-CMS was crossed with the restorer line AR-3. The fertile $F_1 was emasculated and crossed with the Korean japonica rice varieties of the early maturing Sobaegbyeo, Odaebyeo, Gwanagbyeo and Daeseongbyeo, and of the medium maturing Hwajinbyeo, Paldal, Suwon 224 and Iri 386, and of the late maturing Nagdongbyeo, Palkweng, Hwacheongbyeo and Milyang 97. Each of the three way cross $F_{1S} was segregated into fertile and sterile individuals. The sterile individuals in each cross were discarded and the fertile individuals were emasculated and backcrossed with the Korean japonica rice varieties. The same process was applied from BC$_1$F$_1$ to BC$_4$F$_1$ generation. In the ${BC_4}{F_1}of each cross, the male sterile individual was crossed with the recurrent Korean japonica variety which was maintainer of male sterility. The male sterile lines of ${BC_6}{F_1}were named as Sobaegbyeo R, Odaebyeo R, Gwanagbyeo R, etc. The fertile individuals homozygous in pollen fertility were selected from the ${BC_4}{F_2}generation and named as Sobaegbyeo R, Odaebyeo R, Gwanagbyeo R, etc. Agronomic characteristics of the CGMS, restorer lines with backgrounds of Korean japonica, and the recurrent Korean japonica rice varieties grown in the field condition were compared. Culm length of the CGMS lines tended to be shorter than that of the recurrent parent, however no significant differences in heading date, panicle length and yield component were found among the CGMS, restorer and recurrent lines.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.232-242
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• 2017

The goal of marker-assisted backcrossing (MAB) is to significantly reduce the number of breeding generations required by using genome-based molecular markers to select for a particular trait; however, MAB systems have only been developed for a few vegetable crops to date. Among the types of molecular markers, SNPs (single-nucleotide polymorphisms) are primarily used in the analysis of genetic diversity due to their abundance throughout most genomes. To develop a MAB system in Chinese cabbage, a high-throughput (HT) marker system was used, based on a previously developed set of 468 SNP probes (BraMAB1, Brassica Marker Assisted Backcrossing SNP 1). We selected a broad-spectrum TuMV (Turnip mosaic virus) resistance (trs) Chinese cabbage line (SB22) as a donor plant, constructing a $BC_1F_1$ population by crossing it with the TuMV-susceptible 12mo-682-1 elite line. Foreground selection was performed using the previously developed trsSCAR marker. Background selection was performed using 119 SNP markers that showed clear polymorphism between donor and recipient plants. The background genome recovery rate (% recurrent parent genome recovery; RPG) was good, with three of 75 $BC_1F_1$ plants showing a high RPG rate of over 80%. The background genotyping result and the phenotypic similarity between the recurrent parent and $BC_1F_1$ showed a correlation. The plant with the highest RPG recovery rate was backcrossed to construct the $BC_2F_1$ population. Foreground selection and background selection were performed using 169 $BC_2F_1$ plants. This study shows that, using MAB, we can recover over 90% of the background genome in only two generations, highlighting the MAB system using HT markers as a highly efficient Brassica rapa backcross breeding system. This is the first report of the application of a SNP marker set to the background selection of Chinese cabbage using HT SNP genotyping technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.78-83
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• 1979

Eight characters namely stalk length of trifoliate, stalk length of terminal leaflets, length of terminal leaflets, width of terminal leaflets, area of terminal leaflets, length of laternalleaflets, width of laternal leaflets, area of laternal leaflets in leaf parts of soybeans were measured to estimate the heritability values in percentage and relationships between those characters. Five parents and six different $_{x}\textrm{F}_2 generations and two backcross generations were used as the materials. The results obtained are summarized as follows: 1. Eight quantitative characters were differ from varieties. and hybrids from different cross combinations. 2. Heritability values of stalk length were showed the lowest, values of leaf length were lower than those of leaf width in both of main leaflets and laternal leaflets, and other values of leaf area in main and laternal leaflets were showed the highest values. 3. It was also recognized that there were close relationships between leaf length and leaf area, leaf width and leaf area in main leaflets and laternal leaflets, and area of main leaflets and laternal leaflets. There was, however, no any relationship between stalk length and other characters, and between length and width of main leaflets and laternal leaflets.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.412-419
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• 1988

Cold-induced sterility is a problem of rice (Oryza sativa L.) production in temperate regions and high elevation tropics. The present study was conducted to measure combining ability, determine character associations. and to evaluate effectiveness of F$_2$selection for tolerance to this type of cold injury. The F$_1$, F$_2$, F$_3$ and reciprocal backcross F$_1$ populations of a nine-parent diallel were grown at Davis, California. a relatively cool location for rice. Additive genetic variance was predominant but some non -additive genetic variance existed for cold tolerance. Good general combining ability (GCA) was generally associated with the cold tolerant parents, 'M-201', and 'L-201', and poor GCA with the most susceptible parent. 7703008. Sterility was positively correlated with late heading. negatively with mature plant height. and negatively with spikelet number. Of the three agronomic characters, heading date had the greatest influence on sterility. Selection of F$_2$'s in seven crosses involving M-101, the most cold-tolerant parent, was effective for increasing cold tolerance. Realized heritability estimates for cold tolerance averaged 0.53, and observed selection response for cold-induced sterility averaged -9.4 percentage points.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.226-235
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• 1991

This experiment was carried out to obtain the information on the crossability, germination rate, and pollen viability of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results are summarized as follows. Seed set was 28.8 to 41.8% (ave-raged 34.1%) in the cross between triticale and wheat, which resulted in 3.61% in F$_2$(selfed F$_1$), 3.99% in F$_1$/P$_1$ 21. 9% in F$_1$/P$_2$ respectively. However, seed set was extremely low in reciprocal crosses when triticale was used as male. In the backcross, crossability was higher in F$_1$/wheat and triticale/F$_1$ than that in wheat/F$_1$ and F$_1$/triticale, respectively. Germination rate of the crossed seed was 95% in F$_1$ 66.3% in F$_2$ (selfed F$_1$), 62.0% in F$_1$/P$_1$ and 81.0% in F$_1$/P$_2$ from the cross between triticale and wheat, respectively. When triticale cv. Sinkihomil was used as male, seeds were degenerated because of the failure of endorsperm development. This might be caused by AAABBBDDR genome constitution in the cytoplasm from a hexaploid wheat. Pollen fertility of F, plant was averaged 34.1% in the cross between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate in the cross between triticale and wheat were detected.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.269-276
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• 2008

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 to rice blast, quantitative trait loci (QTLs) conferring the resistance for races and blast nursery screening 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 resistant) and Chucheong (highly susceptible). Twelve QTLs against nine blast races inoculated were detected on chromosomes 1, 2, 4, 6, 7, 11 and 12. They explained from 5.1% to 34.9% of total phenotypic variation. Eight QTLs against blast nursery screening in four regions for three years were detected on chromosomes 1, 2, 4, 11 and 12. The phenotypic variation explained by each QTL ranged from 4.3% to 37.7%. Three chromosome segment substitution lines (CSSLs) of $BC_2F_6$ by backcross method were developed to transfer the QTLs into the susceptible cultivar Chucheong as a recurrent parent. A CSSL4-1 containing two QTLs qLB6.2 and qLB7 against blast races showed to the reaction of 6 to 7 at blast nursery in two regions for two years. The CSSL4-2 and CSSL93 containing QTLs, qLB11.2 and qLB12.1 of the resistance against leaf blast in blast nursery screening, respectively, had enhanced the resistance for blast nursery screening across two regions and in two years.

• Molecules and Cells
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• v.25 no.3
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• pp.407-416
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• 2008

Thirteen near-isogenic lines (NILs) of japonica rice were developed via a backcross method using the recurrent parent Chucheong, which is of good eating quality but is susceptible to Magnaporthe grisea, and three blast resistant japonica donors, Seolak, Daeseong and Bongkwang. The agro-morphological traits of these NILs, such as heading date, culm length, and panicle length, were similar to those of Chucheong. In a genome-wide scan using 158 SSR markers, chromosome segments of Chucheong were identified in most polymorphic regions of the 13 NIL plants, and only a few chromosome segments were found to have been substituted by donor alleles. The genetic similarities of the 13 NILs to the recurrent parent Chucheong averaged 0.961, with a range of 0.932-0.984. Analysis of 13 major blast resistance (R) genes in these lines using specific DNA markers showed that each NIL appeared to contain some combination of the four R genes, Pib, Pii, Pik-m and Pita-2, with the first three genes being present in each line. Screening of nine M. grisea isolates revealed that one NIL M7 was resistant to all nine isolates; the remaining NILs were each resistant to between three and seven isolates, except for NIL M106, which was resistant to only two isolates. In a blast nursery experiment, all the NILs proved to be more resistant than Chucheong. These newly developed NILs have potential as commercial rice varieties because of their increased resistance to M. grisea combined with the desirable agronomic traits of Chucheong. They also provide material for studying the genetic basis of blast resistance.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.337-344
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• 2001

The house fly (Musca domestica L.) strains were derived from the Yumenoshima III strain by selecting with cypermethrin and methomyl for 19 and 16 generations, respectively. The resulting strains, cypermethrin resistance strain (Cyp-R19) and methomyl resistance strain (Met-R16), showed high level of resistance by 12906 and 51 times, respectively, comparing with the susceptible SRS strain. The Cyp-R19 strain was resistant to synthetic pyrethroids such as deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin, showing > 11000, 1231, 103, 292 times higher $LD_{50}$ values than the SRS strain, respectively. It was also resistant to 3 organophosphates and 2 carbamates such as fenitrothion, profenofos, pyridaphenthion, benfuracarb, methomyl, showing resistance ratios fo 51, 17, 49, 39 and 62 comparing to SRS strain. The Met-R16 strain was resistant to synthetic carbamate benfuracarb, showing 6 times higher $LD_{50}$ value than SRS strain. It was also resistant to 4 organophosphates such as acephate, fenitrothion, profenofos and pyridaphenthion, showing > 40, 103, 19, 60 times higher $LD_{50}$ value. It was also resistant to 5 pyrethroids and a pyrrole such as cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin and chlorfenapyr, showing 3030, 249, 4063, 34, 330 and 86 times higher $LD_{50}$ values than the SRS strain. Cyp-R14 strain which was selected for 14 generations by cypermethrin and developed 11014 times higher resistance to the SRS strain was used in the dominance and linkage group analysis. Cypermethrin resistance inheritance was incompletely dominant in house fly as judged by the reciprocal cross between the resistant and susceptible strains. The linkage group analysis for the major factors responsible for this resistance was carried out by the$ F_1$male-backcross method, using susceptible multi-chromosomal marker aabys strain. The major factors for cypermethrin resistance were located on the 1st, the 3rd and the 4th chromosomes, and the effect of the 3rd chromosome was most prominent.