In Korea, native or open pollinated corn varieties that were not improved before 1960 were cultivated. The 1960s was a step that created the foundation for the development of varieties. In 1962, systematic corn breeding was started when the synthetic type ‘Hwangok 2’ was distributed to farmers. The 1970s was the era of the change from synthetic varieties to hybrid ones, with a focus on the development of single-cross hybrids among the corn hybrids. The single-cross corn hybrid, ‘Suwon 19’, was an epoch-marking variety that had a unit-yield closer to that of advanced countries. The 1980s was a time when the breeding direction was changed from grain corn to silage because the corn cultivation area for silage increased rapidly with the government's livestock promotion policy, and the corn seed supply system of single-cross hybrids was established. In the 1990s, the era of globalization and the launching of imports of agricultural products, the living standards of consumers became more advanced, and the development system of corn varieties was established for various use purposes. As we entered the 2000s, it started the heyday of developing corn varieties, with 29 corn varieties of various use purposes and excellent cultivation stability developed. In the 2010s, the scope of corn variety development expanded from government or universities to private seed companies. Thus, the corn varieties in Korea have changed and developed in response to the situation of the times, and there are currently 110 corn varieties registered with Korea Seed & Variety Service (KSVS). In the future, vegetable corn is expected to be continuously developed, with functional ingredients such as strengthening vitamins, trace elements, and antioxidant components. Specialized grain corn, such as lysine and maltodextrin, will be developed and commercialized in order to improve the value added. In the case of silage corn, there will be varieties of early maturing and late planting adaptability, with no more than 110 days until maturity, suitable for the cropping system, such as second cropping and double cropping, as well as high digestion rate and nutrition varieties with high feed value, and excessive water tolerance corn varieties that adapt well to paddy fields. Furthermore, it is expected that corn varieties that adapt well to Southeast Asia, Latin America, and Africa will continue to be developed and supplied.

Recently, several attempts have been undertaken to develop breeding technologies by combining new biotechnologies. Gene-editing technology is currently one of the most interesting areas. The plant breeding methods using this technique have the advantage of greatly improved accuracy and efficiency of the plant genetic correction compared with conventional breeding methods, which has raised expectations for the useful application of this technology as a cutting-edge breeding technology. Although not all countries around the world currently have established appropriate regulation policies on crops developed with gene-editing technology, the number of cases in which GMO regulations are not applied on a case-by-case basis according to the scientific background is growing. However, Korea has not yet established policies on which criteria should be applied to crops generated from the application of gene-editing technology. As the number of cases of crop development and commercialization using gene-editing technology is expected to increase in the near future, it will be necessary to prepare reasonable policies to support developers and seed industries in Korea to ensure harmonization with international regulatory policy trends.

In recent years, new plant breeding technologies (NPBT) have had enormous effects on breeding and the agricultural industry. In particular, genome editing technology, including site-directed nuclease technologies, has progressed dramatically since the first-generation Zinc finger nucleases to the third-generation clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9). CRISPR/Cas9 technology has yielded a revolutionary breakthrough in the accurate, efficient, and user-friendly genome editing of eukaryotes. Several methods for basic research and applications, such as knock-out, base editing, gene targeting, and transcriptional activation or repression have been derived from CRISPR/Cas9 technology. Herein, we will describe the current progress in NPBTs and also summarize the crops developed by NPBTs. After analyzing the current status of NPBTs and crop development, we have proposed potential strategies for crop development using NPBTs.

In recent years, novel plant breeding techniques (NPBTs) have emerged, and safety assessment of the novel plant(s) generated using the NPBTs has drawn the attention of many stakeholders. The notable characteristics of the novel plants are as follows: firstly, it is almost impossible to distinguish from the natural mutations in the conventional counterparts, because site-directed nuclease (SDN) and oligonucleotide-directed mutagenesis (ODM) could introduce short indel(s) in the targeted region(s) of the chromosomes. Secondly, the genome constitution of novel plants is almost identical to that of their conventional counterparts, eventually becoming indistinguishable by the introduction of only unmodified gene(s) from sexually compatible species to the target host plant. Thirdly, it is possible to generate new plants that have the desired traits, but without introducing genes. These plants will have some modified bases in their genome by selecting null-segregant(s) from heterozygous transgenic plants or by other epigenetic methods. The Organisation for Economic Co-operation and Development (OECD) and many countries developing genetically modified organisms (GMOs) have concluded that novel plants developed using SDN, ODM, cisgenesis, intragenesis, or null-segregant techniques are treated in the same manner as non-genetically modified (GM) plants or may even have less strict risk assessments depending on the case. Additionally, grafting and agro-infiltration are methods that can be used to avoid or reduce the burden of current strict GMO risk assessment. The risk assessments of some of the novel plants have already been performed and those of commercially important plants are expected to be performed in the near future. Hence, it is necessary to develop a competitive and practical NPBT that can mitigate the concern and revulsion toward GMOs in Korea.