• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.464-469
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• 2011

Virus diseases often cause serious damage to rice production in Asia. The lack of information on virus resistance genes has been a major obstacle for the breeding of resistant varieties. In order to identify DNA marker associated with resistance against rice stripe virus (RSV), the quantitative trait locus (QTL) was carried out using advanced backcross population developed from a cross between RSV-resistant tongil type cultivar Shinkwang and susceptible japonica cultivar Ilpum. A RSV resistance QTL $qSTV11^{SG}$ explaining 44.2% of the phenotypic variation was identified on chromosome 11 of Tongil type rice cultivar 'Shingwang'. $qSTV11^{SG}$ was tightly linked to DNA marker RM6897. The RM6897 divided as resistance type allele and susceptible type alleles. Twenty seven resistant varieties showed the resistant-type allele and 23 susceptible varieties were susceptible-type allele to the marker of RM6897. This results and the molecular markers presented here may be useful in rice breeding for improving RSV resistance in japonica rice.

• The Plant Pathology Journal
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• v.36 no.1
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• pp.11-28
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• 2020

Faba bean (Vicia faba L.) is one of the most important legume crops in Egypt. However, production of faba bean is affected by several diseases including fungal diseases. Fusarium wilt incited by Fusarium oxysporum Schlecht. was shown to be the most common wilt disease of faba bean in Assiut Governorate. Evaluation of 16 faba bean genotypes for the resistance to Fusarium wilt was carried out under greenhouse conditions. Three molecular marker systems (inter-simple sequence repeat [ISSR], sequence related amplified polymorphism [SRAP], and simple sequence repeat [SSR]) and a biochemical marker (protein profiles) were used to study the genetic diversity and detect molecular and biochemical markers associated with Fusarium wilt resistance in the tested genotypes. The results showed that certain genotypes of faba bean were resistant to Fusarium wilt, while most of the genotypes were highly susceptible. The percentage of disease severity ranged from 32.83% in Assiut-215 to 64.17% in Misr-3. The genotypes Assiut-215, Roomy-3, Marut-2, and Giza2 were the most resistant, and the genotypes Misr-3, Misr-1, Assiut-143, Giza-40, and Roomy-80 performed as highly susceptible. The genotypes Assiut-215 and Roomy-3 were considered as promising sources of the resistance to Fusarium wilt. SRAP markers showed higher polymorphism (82.53%) compared with SSR (76.85%), ISSR markers (62.24%), and protein profile (31.82%). Specific molecular and biochemical markers associated with Fusarium wilt resistance were identified. The dendrogram based on combined data of molecular and biochemical markers grouped the 16 faba bean genotypes into three clusters. Cluster I included resistant genotypes, cluster II comprised all moderate genotypes and cluster III contained highly susceptible genotypes.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.151-161
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• 2021

Fusarium wilt disease of tomato plants caused by Fusarium oxysporum f.sp. lycopersici (FOL race2) is one of the most important diseases of tomatoes worldwide. In the competition between tomato and FOL, the FOL can win by overcoming the immune system of tomato plants. Resistant interaction between the FOL race2 and tomato plants is controlled by avirulence genes (AVR2) in FOL and the corresponding resistance genes (I2) in tomato plants. In this study, 7 FOL isolates (KACC) were used to test their pathogenicity, and FOL race2 was selected because it is a broad problem in Korea. The Fol40044 isolates showed the most severe pathogenicity, and the avr2 gene was also isolated and identified. Moreover, to select resistance, 20 tomato varieties were inoculated with the Fol40044, and the degree of pathogenicity was evaluated by analyzing the expression of the avr2 gene. As a result, three resistant tomato varieties (PCNUF73, PCNUF101, PCNUF113) were selected, and the expression of the avr2 gene was much lower than that of the control Heinz cultivar. This result shows that the screening assay is very efficient when the avr2 gene is used as a marker to evaluate the expression level when selecting varieties resistant to tomato wilt disease. Based on these results, it is possible to isolate the I2 gene, which exhibits resistance and molecular biological interactions with the AVR2 gene from the three tomato-resistant varieties. The I2 gene provides breeders more opportunities for Fusarium disease resistance and may contribute to our understanding of their interactions with the FOL and host plant.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.413-421
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• 2011

The main objective of this study was to develop the multi-resistance lines to insects(brown planthopper; BPH, rice green leafhopper; GRH) and disease(blast; BL, bacterial blight; BB and rice stripe virus disease;RSV) with good grain quality and plant type by combining conventional breeding and marker assisted selection(MAS) and to eliminate the linkage drag effects between Bph1 gene and culm length, we conducted MAS of Bph1 gene in advanced backcross and double cross progenies. 'Nampyeong', 'Junam' and 'Milyang220' were used as the parent in this study. 'Milyang220' was used as the donor of brown planthopper resistance gene Bph1 with tall culm length. Two backcross progenies were developed using two recipients 'Nampyeong' carrying GRH resistance gene Grh3(t) with good grain appearance and 'Junam' harboring bacterial blight resistance gene Xa3 with short culm length. Two $BC_1$ generations were resulted from the backcrossing of the $F_1$ plants with recurrent parents 'Nampyeong' and 'Junam'. The second rounds of backcrossing($BC_2$) were derived from the cross of selected resistant $BC_1F_1$ plants based on heterozygous genotype of RM28493 linked to Bph1 gene. The double crossed population was constructed from the cross of between each heterozygous $BC_2F_1$ plants at RM28493 locus of '$Nampyeong^*3$ / Milyang220' and '$Junam^*3$ / Milyang220'., The homozygous alleles in Bph1 gene were selected using co-dominant DNA marker RM28493 in double crossed population. Eighty-five lines with multi-resistance to BL, BB, RSV, GRH and BPH were selected by bio-assay and MAS in generation of double crossing. The culm length, head rice ratio and yield of the selected multi resistance lines was ranged from 71 to 88 cm, from 51 to 93%, from 449 to 629 kg/10a. respectively. We can select a promising multi resistance line similar with 'Nampyeong' of major agronomic traits such as culm legnth, head rice ratio and yield. It was designated as Milyang265. Finally this study was developed the multi resistant varieties against to insects and diseases with the good grain quality 'Milyang265' by the advanced backcross and double cross combining MAS and it can be used as genetic resources of multi-resistance to insect and diseases in rice breeding programs.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.317-323
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• 2000

Molecular genetic techniques can now be applied to the development of advanced plant genotypes, either through genetic transformation or genomic approaches which allow researchers to transfer specific traits using molecular markers. In this paper, we discuss the use of these techniques towards understanding the genetics of blackleg resistance in Brassica. In a comparative mapping study between Arabidopsis thaliana and Brassica napus, 6 R-ESTs, 7 B. napus RFLP markers and a B. napus EST were located in a collinear region of N7 (B. napus) and chromosome 1 (A. thaliana). One of the A. thaliana R-ESTs and 4 of the B. napus RFLPs co-segregated and mapped to the LmRl locus for blackleg resistance. Introgression of blackleg resistance from wild relatives is also investigated with the possibility of accelerating the introgression process via marker assisted selection.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.149-164
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• 2017

Next generation sequencing (NGS) technologies have led to the rapid accumulation of genome sequences through whole-genome sequencing and re-sequencing of crop species. Genomic resources provide the opportunity for a new revolution in plant breeding by facilitating the dissection of complex traits. Among vegetable crops, reference genomes have been sequenced and assembled for several species in the Solanaceae and Cucurbitaceae families, including tomato, pepper, cucumber, watermelon, and melon. These reference genomes have been leveraged for re-sequencing of diverse germplasm collections to explore genome-wide sequence variations, especially single nucleotide polymorphisms (SNPs). The use of genome-wide SNPs and high-throughput genotyping methods has led to the development of new strategies for dissecting complex quantitative traits, such as genome-wide association study (GWAS). In addition, the use of multi-parent populations, including nested association mapping (NAM) and multiparent advanced generation intercross (MAGIC) populations, has helped increase the accuracy of quantitative trait loci (QTL) detection. Consequently, a number of QTL have been discovered for agronomically important traits, such as disease resistance and fruit traits, with high mapping resolution. The molecular markers for these QTL represent a useful resource for enhancing selection efficiency via marker-assisted selection (MAS) in vegetable breeding programs. In this review, we discuss current genomic resources and marker-trait association analysis to facilitate genome-assisted breeding in vegetable species in the Solanaceae and Cucurbitaceae families.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.345-349
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• 1999

This study was carried out to map Bphl and bph2 gene in Mudgo and Sangju13 (Oryza sativa L.) respectively conferring resistance to brown plan-thopper (BPH) and to establish the marker-assisted selection (MAS) system. Bulked seedling (grown for 20 days) test was conducted with the 73 F4 lines derived from a cross between Nagdongbyeo and Mudgo for Bphl and with 53 BC3F5 lines derived from the Milyang95/Sangju13 cross for bph2. Bph1 was mapped between RG413 and RG901 on chromo-some 12 at a distance of 7.5 cM from RG413 and 8.4 cM from RG90l. A recessive gene bph2 was located near RZ76 on chromosome 12 at a distance of 14.4 cM. Bphl and bph2 were linked to each other with a distance of about 30 cM. An RFLP marker, RG413 linked to Bphl, was converted to an STS marker to facilitate the marker-assisted selection. BPH resistant genotypes could be selected with 92% accuracy in a population derived from a line of NM47-B-B.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.52.1-53.1
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• 2004

See Full Text

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.142-143
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• 2006

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.174-175
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• 2005