Genetically modified (GM) crops have been developed to enhance various agronomic traits and increase the production of functional compounds. In the present study, the major agronomic characteristics of protopanaxadiol (PPD)-enriched GM rice, which was developed by introducing dammarenediol-II synthase (PgDDS) and protopanaxadiol synthase (CYP716A47) genes from Panax ginseng into Oryza sativa cv. Dongjin, were evaluated. The stability of the introduced genes was confirmed using PCR and immunostrip tests, which showed consistent expression across multiple generations (T5-T7). Agronomic traits, including days to heading, culm length, panicle length, tiller number, and grain weight per plant, were compared between GM rice and its non-GM counterpart, Dongjin rice. No significant differences were observed for these traits, indicating that genetic modification did not affect the overall plant growth. However, seed morphology analyses revealed that PPD-enriched GM rice had significantly longer brown rice grains. In contrast, other seed traits remained within the natural range of commercial rice varieties. Furthermore, PPD was consistently detected in GM rice, whereas it was absent in non-GM Dongjin rice. These findings suggest that PPD-enriched GM rice maintains a stable agronomic performance while successfully accumulating PPD, supporting its potential as a functional crop. However, further research is required to evaluate its environmental impact, food safety, and efficacy as a functional food source.

A variety of genetically modified (GM) crops have been developed in Korea. In these crops, the resveratrol-enriched transgenic rice plant (Agb0102) has moved ahead to generate the dossier for regulatory review process required for commercialization of GM crop. The resveratrol-enriched transgenic rice plant could be released to farmers for cultivation after national regulators have determined that it is safe for the environment and human health. Here, we developed a PCR-based DNA marker based on flanking sequences of transgene for the discrimination of resveratrol-enriched transgenic rice plant. This DNA markers will be useful for identifying of resveratrol-enriched transgenic rice plant, and can also be used to estimate transgene movement occurred by pollen transfer or seed distribution. Moreover, it is helpful for prompt screening of a homozygote-transgenic progeny in the breeding program.

‘Chindeul’, a new japonica rice cultivar developed from a cross between HR22538-GHB-36-4 having brown planthopper (BPH) resistance and Iksan471 having a good eating-quality and high yield, was developed by the rice breeding team of Department of Rice and Winter Cereal Crop, NICS, RDA in 2012. This variety has about 124 days growth duration from transplanting to harvesting in west-southern coast, Honam and Youngnam plain of Korea. It has 83 cm culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows resistance to bacterial blight pathogen races from K1 to K3, stripe virus and brown planthopper. The milled rice of ‘Chindeul’ exhibits translucent, relatively clear non-glutinous endosperm and medium short grain. It has lower protein content of 5.9% and good palatability of cooked rice compared with Nampyeongbyeo. The milled rice yield performance of this variety is about 5.61 MT/ha in local adaptability test for three years. ‘Chindeul’ would be useful genetic resources for multi-resistance breeding program against disease and insect.

‘Sanhomi’, a new japonica rice cultivar developed from a cross between Sangmibyeo and F₁ plant derived from the cross between Sangju24 and Hwayeongbyeo having bacterial blight and rice stripe virus resistance was developed by the rice breeding team of Sangju Substation, NICS, RDA in 2012. This variety has about 114 days of growth duration from transplanting to harvesting in southern mid-mountainous area of South Korea. It has 70 cm culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows multiple resistance to blast, bacterial blight and rice stripe virus. The milled rice of ‘Sanhomi’ exhibits translucent and, relatively clear non-glutinous endosperm, and medium short grain. This variety has a higher milled rice recovery (67.3%), better palatability of cooked rice and similar amylose content (19.9%) compared with Odaebyeo. The milled rice yield performance of this variety was about 5.60 MT/ha in local adaptability test for three years. ‘Sanhomi’ would be adaptable to southern mid-mountainous of South Korea.

This study was conducted to isolate a salt tolerant gene and to develop salt tolerant rice for reclaimed-saline areas through genetic transformation. A rice c/DRE binding factor 4 (OsCBF4) cDNA was isolated from rice (cv. Nipponbare) using RT-PCR. The full-length cDNA of the CBF4 gene consists of 1,429 nucleotides and 274 amino acid residues. The OsCBF4 shares from 33 to 49% identity of deduced amino acid sequence with other CBFs of rice. In order to develop salt tolerant rice, transgenic rice plants containing the OsCBF4 gene were obtained via Agrobacterium-mediated transformation. The stable incorporation of the OsCBF4 gene into rice genome was confirmed by PCR and Southern analysis. The stable expression of introduced gene was also validated by RT-PCR analysis in T₂ plants. Biological assay of T₃ progeny of the transgenic plants in Yoshida solution containing 120 mM Nacl for 2 weeks, confirmed that the OsCBF4 confers salt tolerance to transgenic rice plants. OsCBF4 transgene in the transgenic line CBF4-10 was markedly expressed up to over three-fold in the leaf by 120 mM NaCl treatment. Real-time PCR analysis revealed that the levels of the transgene expression were markedly increased under salt treatment. The transgenic line CBF4-10 which showed highest ability to recover from the saline stress could be used as a potential source for salt tolerance in rice breeding programs.

This study was conducted to develop multi-resistant lines to brown planthopper, bacterial blight, and rice stripe virus using anther culture in rice. A total of 213 double haploid lines were developed the cross between HR26234-12-1-1 conferring resistant to bacterial blight and rice stripe virus and SR30071-3-7-23-6-2-1-1 conferring resistant to brown planthopper, bacterial bight, and rice stripe virus. Using DNA molecular marker, HR26234 and SR30071 were confirmed to have Xa3+xa5+Stvb-i and Bph18+Xa4+Stvb-i, respectively. All double haploid lines carried Stvb-i, and Bph18+Xa3, Bph18+Xa4, Bph18+Xa3+xa5, Bph18+Xa4+xa5, bph18+Xa3, bph18+Xa4, bph18+Xa3+xa5, and bph18+Xa4+xa5 combinations were identified. Segregation distortions such as no combinations carrying Bph18(or bph18)+xa5+Stvb-i and fewer lines carrying Bph18 than bph18 were occurred in DH population. Brown planthopper resistant lines carrying Bph18 showed longer culm length than susceptible lines. Selected Bph18+Xa4+xa5+Stvb-i combination lines with short culm conferred resistant to brown planthopper, bacterial blight, and rice stripe virus, while showed deleterious effects such as spikelet sterility, lower yield, and vulnerable to lodging than standard and comparative varieties. Using anther culture, we rapidly developed multi-resistant lines to brown planthopper, bacterial blight, and rice stripe virus. However, distorted segregation in DH population and linkage drag with Bph18 were obstacles to develop practical multi-resistant cultivars.