Fruit development period (FDP), defined as the time between full bloom and maturity, varies greatly in peaches (Prunus persica L. Batsch). It is necessary to develop molecular markers associated with maturity date to extend the harvest season in new peach cultivars. We designed the 260 SSR primer set covering the entire genome of approximately 300 kb to 1 Mb based on P. persica cultivar ‘Mihong’ genome sequence. The SSR markers were used to survey the relationship between the parentages ‘Yumeyong’ and ‘Chiyomaru’ and their offspring cultivars ‘Mihong’, ‘Yumi’, ‘Misshong’ and ‘Soomee’. Male cultivar ‘Chiyomaru and its offspring cultivars ‘Mihong’, Yumi’, and ‘Misshong’ are early and middle maturity cultivars with FDP of 77, 76, 82, and 108 days, respectively, whereas female cultivar ‘Yumyeong’ and its offspring cultivar ‘Soomee’ are late maturity cultivars with FDP of 128 days. Three regions of SSR markers could distinguish between early, middle, and late maturity cultivars. In the early stages of breeding, these markers will be used for marker-assisted selection (MAS) in the parentages ‘Yumyeong’ and ‘Chiyomaru’ and their offspring cultivars.

To improve the seed purity management system of Korean wheat cultivars, 50 Korean wheat cultivars were subjected to chemical assays for grain color, genotyping of grain weight-related genes, and grain image analysis. The tested cultivars were primarily classified by NaOH and ninhydrin tests as white (26%) and red (74%) cultivars, as well as high PPO activity (48%), and low PPO activity (52%) cultivars, respectively. The allelic variations of Tamyb10 gene revealed Tamyb-A1a/Tamyb-B1a/Tamyb-D1a as the major allelic combination in white wheat and five different Tamyb10 genotypes (i.e., aba, abb, baa, bba, and bbb) in red wheat. Those cultivars with high PPO activity possessed the Ppo-A1a/Ppo-B1b/Ppo-D1b genotype, while those with low PPO activity possessed the Ppo-A1b/Ppo-B1a/Ppo-D1a genotype. In the grain image analysis, long grain cultivars displayed increased grain width, circularity, and area. Based on cluster analysis of grain traits, the Korean wheat cultivars were classified into two groups - 1) large red grain cultivars released before 2000, and 2) small red grain cultivars and white wheat cultivars released after 2000. Further research is required to determine the effects of grain filling conditions on the grain characteristics of Korean wheat cultivars and to develop efficient and reliable molecular markers for an improved seed purity management system.

Low-temperature damage at the seedling stage is one of the most significant natural obstacles to wheat’s growth. In domestic wheat breeding programs, the selection of cold-tolerant varieties is crucial for the development of superior wheat varieties. Traditionally, the extent of damage caused by freezing wheat is estimated through visual observation. In this study, we compared the RGB image analysis method with conventional visual evaluation and chlorophyll content analysis methods to determine if this method could accurately quantify the cold tolerance discrimination of wheat in the field. First, single-leaf-level RGB image analysis revealed a pattern similar to dead leaf ratio and chlorophyll content in three grades of freezing injury. Next, we compared the significance of plant-level RGB image analysis. The greenness index by RGB image analysis showed a higher correlation with dead leaf ratio by visual evaluation. Finally, 40 wheat varieties were planted in the field and wheat canopy images were collected at the seedling stage after wintering. There was a high correlation between the greenness index and the visual evaluation. However, there was no correlation between dead leaf ratio and visual evaluation or greenness index as determined by RGB image analysis. These findings suggest that using RGB image analysis rather than visual evaluation can be useful in assessing freeze damage in wheat fields.

This study was conducted to reset the transplanting period to produce high-quality rice in the South regions due to the rise in air temperature caused by global warming. From May 15 to June 25, transplants were performed five times every ten days. Quantity and quality were comprehensively reviewed, including watering season, ripened grain rate, head rice rate, head rice yield, protein content, and palatability. In the southern plains, medium-late and medium maturing cultivars yielded the most when transplanted on June 15, while early maturing cultivars yielded the most when transplanted on June 25. Considering the quality and quantity of rice, the optimal transplanting window for medium-late maturing cultivars is June 10-15, for medium maturing cultivars it is June 15-20, and for early maturing cultivars it is June 25. In the middle of the southern region, the highest yield was on June 25 for medium-late maturing and June 15 for medium maturing and early maturing. However, considering the quality, the best time for transplanting is June 10 for medium-late maturing, June 5 for medium maturing, and June 15 for early maturing. As a result of the rise in average temperature, the transplantation period was delayed by at least 4 to 16 days in all varieties and regions relative to the traditional transplantation duration. In summary, it is determined that a suitable transplanting period must be established in response to the increase in average temperature to ensure the production of high-quality rice.

Watermelons are grafted to prevent soil-borne diseases such as Fusarium wilt (FW) and increase their resistance to abiotic stress. Root-knot nematodes (RKN) are a contributing factor to economic loss in several cucurbits, including watermelon. Growing resistance varieties is an effective way to reduce the damage caused by soil-borne diseases. Resistance evaluation was performed on 50 watermelon lines to select rootstocks resistant to FW and RKN. Fusarium oxysporum f. sp. niveum race 2 was inoculated into 10-day-old seedlings using a root dipping method, and resistance was evaluated for four weeks. The 37-day-old watermelon seedlings were inoculated with Meloidogyne incognita and evaluated 60 days later. Three lines (IT199860, PI296341-6, and PI532811) were resistant to FW race 2, while one line (PI494527) was moderately resistant. Three lines (PI296341-5, PI457916-2, and PI457916-5) were RKN resistant. The PI296341-6 line was selected for its resistance to FW and moderate resistance to RKN. These findings imply that the identified resistant lines can be used in rootstock breeding programs against FW and/or RKN.

To determine whether Fourier-transform infrared (FT-IR) spectral analysis based on multivariate analysis for whole-cell extracts can be used to discriminate different countries of Perilla seeds at the metabolic level, leaves of Perilla seeds were subjected to FT-IR spectroscopy. FT-IR spectral data of leaves were analyzed by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and hierarchical clustering analysis (HCA). FT-IR spectra confirmed typical spectral differences between frequency regions of 1,700-1,500, 1,500-1,300, and 1,100-950 cm^-1. These spectral regions reflect the quantitative and qualitative variations of amide I, II in amino acids and proteins (1,700-1,500 cm^-1), phosphodiester groups in nucleic acids and phospholipids (1,500-1,300 cm^-1), and carbohydrates (1,100-950 cm^-1). PCA revealed separate clusters corresponding to their country relationship. Thus, PCA could be used to distinguish between countries of origin with different metabolite contents. And PLS-DA showed a similar country classification of Perilla seeds. Furthermore, these metabolic discrimination systems could be used for the rapid selection and classification of useful field crop cultivars.

Bacterial pustule is a major bacterial disease in most soybean-growing regions of Korea, resulting in soybean yield reductions of up to 60%. In this study, we aimed to understand the differences in disease severity caused by three strains of Xanthomonas citri pv. glycines, including two newly differentiated strains (K29 and K100) and the conventional representative strain, 8ra. Seventeen major soybean cultivars and 14 breeding lines were inoculated and compared for their reactions to the three strains of Xcg. The two new strains caused higher levels of disease severity, resulting in a greater number of susceptible cultivars. The landrace PI 547711, like Williams 82, was highly resistant to all Xcg strains; however, the other six cultivars that were resistant to 8ra, including Daepung2, were susceptible to the new strains (K29 and K100). In particular, the most widely grown cultivars, Daewon and Daepung2, were highly susceptible to K100. All of the breeding lines except two were also vulnerable to the new strains, K100 and K29. Of the breeding lines, SS05004-1-1-4-2-3-4 and SS05022-5-4-2-4-4-4 were resistant to the three Xcg strains, at similar levels to that of Williams 82. The breeding lines and cultivars evaluated in this study may be used to develop breeding materials resistant to new Xcg strains in the future. In addition, establishment of an improved disease evaluation system for bacterial pustule, by using multiple representative strains, is strongly recommended for breeding programs, to increase the efficiency and accuracy of selection for resistance as the pathogenic diversity of X. citri pv. glycines changes.

‘Sinhwangok2’ is a single cross maize F₁ hybrid (Zea mays L.) that was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA, in 2018. This yellow high-yielding intermediate maize hybrid was obtained by crossing between two inbred lines― KS214 and KS215. After advanced yield trials over two years in Suwon, a regional yield trial for ‘Sinhwangok2’ was conducted to evaluate its growth and yield at three different locations, from 2016 to 2018. ‘Sinhwangok2’ requires 72 days for silking and its plant height is 243 cm, similar to that of ‘Jangdaok’; its ear height ratio is 49%, like that of ‘Jangdaok’, and the hybrid shows resistance to lodging. The number of ears per 100 plants was found to be 100 and the ear length of ‘Sinhwangok2’ is 19.5 cm, which is shorter than that of ‘Jangdaok’. The weight of 100 seeds of ‘Sinhwangok2’ is 30.8 g, similar to that of ‘Jangdaok’. This hybrid shows moderate resistance to southern leaf blight (Bipolaris maydis). It has moderate resistance to European Corn Borer (Ostrinia nubilalis). The grain yield (i.e., 9.41 ton/ha) of ‘Sinhwangok2’ was found to be 13%, which is higher than that of ‘Jangdaok’. Seed production of ‘Sinhwangok2’ was 2.36 ton/ha and was considered acceptable due to a good synchronization of flowering period during crossing between the seed parent, KS214, and the pollen parent, i.e., KS215, in Yeongwol and F₁ seed yield. ‘Sinhwangok2’ can thus be a suitable cultivar for all plain areas in Korea and can possibly be cultivated via double cropping with winter forage crop because of their early maturity. (Registration No. 8963).

Brown planthopper (BPH, Nilaparvata lugens Stal) is a major agricultural pest that plays a key role in reducing rice yield. Rapid climate change has emphasized the necessity of cultivating multi-resistant cultivar rather than cultivar with single-resistance to specific pests. Accordingly, the Plant Molecular Breeding Laboratory of the Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu 41566, Korea developed the ‘Drimi 1ho’ rice cultivar with enhanced resistance to blast and bacterial blight as well as BPH breeding in 2008. In order to breed ‘Drimi 1ho’, ‘Samgang’ and ‘Nagdong’ were crossed and backcrossed with ‘Junam’, after which the pedigree breeding method was applied. Finally, ‘Drimi 1ho’ was selected through analysis of resistance to insect and viral disease, yield, and grain quality. ‘Drimi1ho’ is strongly resistant to BPH and has a wide range of resistance to pests. ‘Drimi 1ho’ is also resistant to blast and bacterial blight (K₁, K₂, K₃), which occurs most frequently and causes serious damage to crops in the Republic of Korea. The agricultural characteristics of 'Drimi 1ho' were similar or improved from 'Junam'. In particular, ‘Junam’ is susceptible to BPH and bacterial blight. ‘Drimi 1ho’ made up for the shortcomings of ‘Junam’ with acquired strong and broad-spectrum resistance. Finally, ‘Drimi 1ho’ had a yield of 563 kg/10 a under normal cultivation and can thus be an adaptable cultivar in south mid-mountainous areas in the Republic of Korea (Registration No. 3685).

Rice is an important crop used as a staple food in most of the world; however the occurrence of pests is increasing due to climate change. In particular, the brown planthopper (BPH, Nilaparvata lugens stal) is a key cause of rice yield loss. In response to the era of unpredictable climate change in the future, the Plant Molecular Breeding laboratory of the Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu 41566, Korea bred the ‘Drimi2ho’ strain, which is resistance to BPH or various pests and of excellent eating quality. In order to cultivate ‘Drimi2ho’, ‘Samgang’ and ‘Nagdong’ were crossed and the derived seeds were backcrossed with ‘Junam’, and the pedigree breeding method was applied. During the application of the pedigree method, agricultural characteristics which are investigated in the field were found to be excellent, and the best line for various disease resistance, grain quality, and yield was finally selected as ‘Drimi2ho’. ‘Drimi2ho’ has strong resistance to BPH and its range of resistance to major pests and viral diseases such as blast and bacterial blight on rice is quite wide. In the field, the main agricultural characteristics of ‘Drimi2ho’ were similar to or improved from those of ‘Junam’. ‘Drimi2ho’ is a cultivar with enhanced disease and pest resistance and a wide spectrum while maintaining the good eating quality. ‘Drimi2ho’ yielded 584 kg/10a in ordinary cultivation under normal level of fertilization in south mid-mountainous areas of Korea. Drimi2ho’ can thus be a standard cultivar in Korea due to its varied resistance to multiple diseases and excellent grain quality. (Registration No. 4686).

‘Heukharang’ is a pure line variety selected from native seeds; this lettuce variety has stronger leaves and longer foliar than traditional red skirt varieties. From 2011 to 2015, productivity was tested by collection and pure line selection. The new breed, ‘Heukharang’, was found to be narrow and black oval with anthocyanin pigments evenly spread over the leaves. ‘Heukharang’ had a stronger bitter taste than the Red Skirt variety, since its lactucin content was >100 times higher. This cultivar also showed a much higher content of chlorogenic acid and tocopherol. This new variety ‘Heukharang’ can thus be recommended as a variety that can fully utilize functional ingredients in lettuce, since it is close to the existing variety of red skirt lettuce and has more functional ingredients (Registration No. 7569).

‘Bbareumi’ is an extremely early maturing rice cultivar with the fastest harvesting time in Korea. To develop ‘Bbareumi’, ‘Joami’ with good quality in Chungnam plain area and ‘Hokuto’ originating from Japan with the fastest heading date among genetic resources were used as breeding materials. After crossing them in 2010, the ‘Bbareumi’ cultivar was developed using the pedigree method. A yield trial was conducted from 2015 to 2016, and a local adaptability test was conducted from 2016 to 2018. The heading date of ‘Bbareumi’ was seven days earlier than ‘Jinbuolbyeo’, showing an average of June 23^rd, and it could be harvested from the end of July to the beginning of August when transplanted early in Chungnam plain area. ‘Bbareumi’ had a short culm length of 63.3 cm and panicle length of 19.3 cm. Milled rice yield was approximately 4.87 MT/ha and the percentage of head rice was 89.2% under normal fertilizer condition. ‘Bbareumi’ will be used as a premium rice brand with newly harvested rice before ‘Chooseok’, Korean Thanksgiving Day and is expected to contribute to the revitalization of double-cropping in the Chungnam plain area (Registration No. 8130).