Leaf size is closely related to photosynthesis and greatly affects rice productivity. Therefore, the search for quantitative trait Locus (QTL) that regulates leaf size is important for improving productivity through rice breeding. The F₉ recombinant inbred line (RIL) population from the cross between ‘Unbong 40’ (large leaves) and ‘Odae’ (ordinary size leaves) was grown in a test field, and the size traits of the flag leaves and 2nd leaves, along with stem and panicle length, were measured. Through QTL analysis of these traits, we detected 20 QTLs on chromosomes 1, 3, 6, 9, 11, and 12. In particular, the flag leaf length QTL qFLL3, the flag leaf area QTL qFLA3, the 2nd leaf length QTL q2LL3-2, and the 2nd leaf area QTL q2LA3 were clustered in the 149.0-161.6 cM region of chromosome 3, indicating that one QTL gene in this region may have pleiotropic effects that regulate the flag leaf length, flag leaf area, 2nd leaf length, and 2nd leaf area. In addition, the flag leaf width QTL qFLW9 and 2nd leaf width QTL q2LW9 were clustered in the 2.1-22.86 cM region on chromosome 9, which suggests that one QTL gene in this region may have pleiotropic effects that regulate both the flag leaf width and 2nd leaf width. These results serve as a valuable reference for breeding programs aiming to increase photosynthesis and yield by identifying QTLs for leaf size traits in Korean japonica rice.

Rice blast is one of the most serious agricultural diseases in the world. Rice blast can be managed using low nitrogen fertilizers, treatment with chemical fungicides, and the most effective resistant varieties. Many genetic resources have been investigated and used along with molecular markers to breed blast-resistant rice varieties. In this study, the genetic diversity of blast resistance genes using 27 functional/linked markers and rice blast incidence over three years was investigated in 296 Korean rice varieties. Blast incidence was determined using a 0-9 scoring system (0=no lesions to 9=dead leaves) in nursery tests. The blast incidence of 296 rice varieties showed a significant correlation between years (r>0.64, p<0.001). The 261 Japonica varieties showed blast resistance compared to 114 mid-late maturing varieties or 96 medium-maturing varieties. 35 Tongil-type varieties also exhibited greater resistance than Japonica varieties. DNA marker-trait association analysis was conducted using 27 DNA markers linked to 19 blast resistance genes. Twelve DNA markers showed significant associations with the average blast incidence over 3 years. The ‘9871.T7E’ marker linked with Pi40 was strongly associated with blast disease, with a phenotypic variance of 24% over 3 years (p<0.001). Among the varieties harboring the Pi40 allele, early maturing varieties accounted for 87%. These results imply that the blast resistance of early maturing Korean varieties is associated with the Pi40 gene. These results will be beneficial for breeding blast-resistant rice in Korea.

‘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).

AbstractIn 2014, a mung bean cultivar, Vigna radiata (L.) R. Wilczek ‘Dado’, was derived from a hybrid between ‘Jeonnam14’ and ‘IT208777’ developed in 2001 at the Jeollanamdo Agricultural Research and Extension Services, South Korea. ‘Dado’ has an erect growth habit, lobed leaflets, green hypocotyls, light yellow corolla, and dull green seed surface. The number of pods per plant was 23.3, 1.5 more than that of the control cultivar ‘Owool’, and the 1000-seed weight was 43 g, 6 g lighter than that of the control. ‘Dado’ and ‘Owool’ exhibited similar field resistance to mung bean mottle virus, cercospora leaf spot, powdery mildew, and lodging. ‘Dado’ had a sprout yield ratio of 824%, 132% higher than that of ‘Owool’, and its hard seed rate was 1.2%, 3.1% lower than that of the control. The average seed yield of ‘Dado’ was 1.9 ton/ha, which was 23% greater than that of ‘Owool’ (Registration No. 5874).

AbstractExtensive research has been conducted in wheat to improve genetic resistance to rust, a major disease that deteriorates wheat yield and quality worldwide. Leaf rust caused by Puccinia triticina is the most prevalent among the three major wheat rust diseases (leaf, stripe, and stem rust) globally and is adapted to a wide range of climates. Approximately 80 genes for leaf rust resistance have been reported, and six (Lr1, Lr10, Lr21, Lr22a, Lr34, and Lr67) have been cloned. Among these cloned genes, Lr34/Yr18/Sr57/Pm38 and Lr67/Yr46/Sr55/Pm46 are of special interest for breeding programs, as they provide pleiotropic resistance to stripe rust, stem rust, and powdery mildew as well as leaf rust. In Korea, knowledge on wheat breeding and genetics for rust resistance is insufficient, as agronomic measures have mainly been used to avoid rust. Therefore, an extensive research program to address the increasing threat of rust epidemics due to climate change is urgently required. Major Korean wheat cultivars, breeding lines, and landraces should be screened for leaf rust resistance. Diverse germplasms also need be introduced through international collaborations to broaden the genetic background for resistance. It is equally important to characterize the distribution of different leaf rust races in Korea and respond to changes in pathogen populations by using effective resistance genes in breeding programs. Research on molecular genetics and genomics needs to be furthered to identify new leaf rust resistance genes and develop efficient molecular markers.

A new lettuce (Lactuca sativa L.) with elliptic and dark green leaves, ‘Sambokhacheong’, which is tolerant to tipburn with good yield, was developed from a cross between ‘Meokchima’ (dark red leaves) and ‘Yeoreumcheongchima’ (high yield, green leaves). The crossing and selection for advanced lines was conducted by the pedigree method in 2006-2012. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Chungcheongnam-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) over three years starting from 2015. The evaluations revealed that this lettuce was early- and medium-maturing leaf lettuce, with a shelf-life of four weeks at 4 ℃, longer than that of ‘Yeoreumcheongchima’. ‘Sambokhacheong’ showed no symptoms of tipburn during hot seasons in the southern parts of South Korea compared ‘Yeoreumcheongchima’. The content of bitter sesquiterpene lactones (latucin, latucin+8-deoxylactucin+lactucopicrin) of ‘Sambokhacheong’ at 57.16 (μg/g, dry weight) was higher than that of ‘Yeoreumcheongchima’. Compared with ‘Yeoreumcheongchima’, the marketable yield of ‘Sambokhacheong’ was 2% higher (at 551 g per plant) and showed late bolting at 111 days after sowing in the summer cultivation season. Its leaves are better, crispier, and sweeter than those of ‘Yeoreumcheongchima’. Therefore, we recommend the new cultivar ‘Sambokhacheong’ for cultivation in hot seasons (Registration No. 6915).

A new mung bean cultivar, Vigna radiata (L.) R. Wilczek ‘Samhwang’, was derived from a cross between ‘Samgang’ and ‘KM9901-3B-15-2-4’ obtained in 2006 and developed at the Jeollanamdo Agricultural Research and Extension Services (JARES) in 2014. ‘Samhwang’ has an erect growth habit, lobed leaflets, green hypocotyls, light yellow corolla, and a dull yellow seed surface. Its stem length was 64 cm, 5 cm shorter than that of the control cultivar ‘Owool’. The 1000-seed weight was 53 g, i.e., 4 g heavier than that of ‘Owool’. ‘Samhwang’ exhibited similar field resistance to mung bean mottle virus, cercospora leaf spot, powdery mildew, and lodging when compared with that of the control cultivar. The sprout yield ratio and hard seed rate were the same as those of ‘Owool’. The average seed yield of ‘Samhwang’ was 1.76 ton/ha, which was 14% greater than that of ‘Owool’ (Registration No. 5877).

Limitation of genetic diversity in japonica rice breeding populations is often identified as a potential obstacle for the development of high yielding cultivars. The use of diverse germplasm in rice breeding has been suggested as one way of combating this problem. This study was conducted to improve the genetic diversity for rice, by developing an advanced backcross population derived from a backcross ‘Junam’ as recurrent parent and ‘IR72’ as a donor parent. Among them, we selected a promising line ‘YR24438-B-B-B-B-132’ containing bacterial blight resistance gene Xa4. Testing in the replicated yield trial in 2009, the ‘YR24438-B-B-B-B-132’ line was selected, and it was designated as ‘Milyang298’. The local adaptability test of ‘Milyang298’ was carried out at three locations from 2014 to 2016 and it was named ‘MY298BB’. The average culm length in the replicated yield trials was 87 cm, which is 15 cm taller than recurrent parent ‘Junam’. Number of spikelets per panicle was significantly lower than in ‘Junam’ but the number of tillers per hill was higher. This variety is resistant to bacterial blight race K1, K2, K3, and K3a.However ‘MY298BB’ showed early leaf senescence at the mature stage and the chlorophyll content of ‘MY298BB’ was significantly lower than that of the recurrent parent ‘Junam’. Moreover the grain filling ratio and yield were significantly lower in ‘MY298BB’ than those of recurrent parent ‘Junam’. Therefore, understanding the leaf senescence mechanism would be useful for improving yield potential in rice.

In this study, genetic analysis was conducted on the inheritance of qualitative traits, such as leaf color, flower color, seed size, and seed hardness, in the F₂ population derived from the cross between var. frutescens and var. crispa. As determined by the separation pattern of each trait in the F₂ population, F₂ plants with a green color were more common than those with a purple color on the leaf surface, whereas F₂ plants with a purple color were more common than those with a green color on the reverse side of the leaf. For flower color, more F₂ plants were observed to have a white color. For seed size, more F₂ plants were observed to have a seed size of above 2 mm, and for seed hardness, more F₂ plants were observed to have characteristics of seed hardness. Our examination of the genetic separation ratios with respect to Mendel’s law of genetics revealed that three traits, leaf color (surface and reverse side) and flower color, did not follow the separation ratio of 1:2:1, and the seed size did not follow the segregation ratio of 3:1, but seed hardness was found to follow the separation ratio of 3:1. The results of this study are expected to provide basic information to help understand the genetic segregation of leaf and seed characteristics in the F₂ population derived from the cross between var. frutescens and var. crispa, and also to provide useful information for breeding studies to assist the development of varieties of Perilla crop.

A cultivar of lettuce (Lactuca sativa L.) with sharply large oval and purple leaf, ‘Jahokmaschima’, which has late bolting and a high yield, was developed from a cross between ‘Bulkkoch’ (dark red leaf color and early bolting) and ‘Cheongpung’ (high yield). The cross and selection for advanced lines was conducted by the pedigree method between 2005 and 2011. The advanced lines were evaluated for yield and adaptability at six locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) for 3 years until 2014. The ‘Jahokmaschima’ lettuce has a gray seed color, and the leaf type of the matured stage is a large oval leaf, leaf no. 67 per plant, and late bolting. In particular, the ‘Jahokmaschima’ has good resistant to tip burn in the growth period. The anthocyanin and vitamin C content of ‘Jahokmaschima’ were lower than those of ‘Tomallin’, at 4.05 mg/100g and 27.7 mg/100g, respectively. The BSL (bitter sesquiterpene lactones; latucin, 8-deoxylactucin, and lactucopicrin) content of ‘Jahokmaschima’ was lower than that of ‘Tomallin’, at 2.120 µg/g DW. Compared with ‘Tomallin’, the marketable yield of ‘Jahokmaschima’ was 1% higher (at 374 g per plant) and particularly improved late in bolting in high temperature cultivation in the field. The shelf-life of ‘Jahokmaschima’ was similar to ‘Tomallin’ at 4ºC. Furthermore, it tasted better, and was crispier and sweeter than ‘Tomallin’. Thus, we recommend that the new cultivar ‘Jahokmaschima’ is suitable for cultivation in spring and fall.

A mungbean cultivar ‘Areum’ (Vigna radiata (L.) Wilczek) was derived from a cross between ‘Samgang’ and ‘KM9901-3B-15-2-4’ at the Jeollanamdo Agricultural Research and Extension Services (JARES) in 2013. ‘Areum’ has an erect growth habit, lobed leaflet, green hypocotyls, light yellow corolla, and a dull green seed surface. Its stem length is 61 cm, which is 5 cm shorter than that of the control cultivar ‘Owool’. The 1000-seed weight is 51 g, which is 2 g heavier than that of ‘Owool’. Its field resistance to mungbean mottle virus, cercospora leaf spot, and powdery mildew is similar to that of the control cultivar, whereas its field resistance to lodging is marginally weaker. The hard seed rate of ‘Areum’ is 6.81%, which is 2.49% higher than that of ‘Owool’. The sprout yield ratio is 7.09, which is similar to that of the control cultivar. The average yield of ‘Areum’ is 1.79 ton/ha, which is 12% more than that of ‘Owool’. (Cultivar registration number: 5876).

A new red butterhead lettuce (Lactuca sativa L.) with transverse broad elliptic, red leaves, ‘Sun Red Butter’, with late bolting and high yield, was developed from a cross between ‘Jajusangchu’ (red leaf color and half crisp) and ‘Dukseomjeokchukmyeon’ (high yield). The crossing and selection for advanced lines was previously carried out using the pedigree method during the period 2001–2009. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongsangnam-do, and Jeju-do) in 2011. The type of matured stage is early and medium butterhead lettuce. The shelf life of ‘Sun Red Butter’ was four weeks longer than that of ‘Germania’ at 4°C. The anthocyanin content of ‘Sun Red Butter’ was lower than that of ‘Germania’ at 11.2 mg/100 g. The BSL (latucin+8-deoxylactucin+lactucopicrin) content of ‘Sun Red Butter’ was higher than that of ‘Germania’ at 32.8 µg/g, DW. The marketable yield of ‘Sun Red Butter’ was higher than that of ‘Germania’ by 67% (at 621.4 g per plant), and ‘Sun Red Butter’ showed a particularly improved yield under high-temperature cultivation in the field. Furthermore, ‘Sun Red Butter’ had better taste characteristics and was crisper and sweeter than ‘Germania’. Therefore, we recommend that the new cultivar ‘Sun Red Butter’ would be suitable for cultivation in spring and fall. Furthermore, this new cultivar could be harvested in a single harvest, as in a head lettuce, and could therefore be managed more efficiently and economically by farmers.

A new lettuce (Lactuca sativa L.) variety ‘Sunny Red Butter’ that belongs to butter-head type has transverse broad elliptical leaf with red color. Crossbreeding of ‘Oriana’ and ‘Cardinale’ was made to obtain seeds of the F1 generation. Subsequent generations were selected using in pedigree methods until 2011, resulting in ‘Sunny Red Butter’. The new variety ‘Sunny Red Butter’ is brown in seeds and the upper part of the leaf is light red and glossy. The leaf stalk is white. It can be harvested from 30 days after planting. The average harvested leaf number is 51 leaves per plant. The average weight is 556.5g per plant, which is 44% higher than a control lettuce variety ‘Germania’. It showed that 30.9 tons/ha production was made in spring, summer, and autumn cultivations for 3 years in 6 areas (Daegwanryeong, Gyeonggi, Chungbuk, Jeonbuk, Gyeongnam, and Jeju) than the control variety ‘Germania’. The shelf-life of ‘Sunny Red Butter’ was 4 weeks for storage at 4℃. Anthocyanin amount (10.3 mg/100g) of ‘Sunny Red Butter’ was lower than that of ‘Germania’. BSL (latucin+8-deoxylactucin+lactucopicrin) amount of ‘Sunny Red Butter’, the bitter ingredients was 26.1 μg/g and higher than BSL amount of ‘Germania’. Leaf hardness of ‘Sunny Red Butter’ was 1,554 kg/cm 2 , which was thicker than ‘Germania’. ‘Sunny Red Butter’ showed better taste (more crispy and sweeter) than ‘Germania’. The new variety ‘Sunny Red Butter’ can be used as lettuce productions during spring and autumn in most area and in summer in highland of Korea.

‘Hyesun’, a new cultivar of leaf lettuce (Lactuca sativa L.) with sharply wrinkled oval and red leaf, produced by a cross between 'Nongjeockchima’ (red leaf color) and ‘Jeockchima’ (high yield) has late bolting and high yield in the field. The cross and selection for advanced lines had been done by the pedigree method from 2002 to 2008. The ‘Hyesun’ has gray seed color and medium elliptic leaves. The yield and adaptability of the advanced lines were evaluated at several locations of Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) for 3 years (from 2009 to 2012). The type of maturity of ‘Hyesun’ is early-medium. The leaf hardness of ‘Hyesun’ is a 1,237kg/cm², which is not thicker than ‘Yeolpungeokchima’. The anthocyanin content of 'Hyesun' is a 88.32mg/100g, which is lower than that of ‘Yeolpungeockchima’. The BSL (Bitter Sesquiterpene Lactones, latucin + 8-deoxylactucin + lactucopicrin) content of ‘Hyesun’ is a 5.0ug/g of DW, which is lower than that of ‘Yeolpungeockchima’. Compared to ‘Yeolpungeockchima’, marketable yield of ‘Hyesun’ was higher by 7% (at 381g per plant) and the bolting time of ‘Hyesun’ was remarkably delayed under high temperature cultivation in the field. The shelf-life of ‘Hyesun’ was four weeks longer than ‘Yeolpungeockchima’ at 4°C. Furthermore, because ‘Hyesun’ is more crispy and sweeter than ‘Yeolpungeockchima’, ‘Hyesun’ has the better taste. So, we recommend that the new cultivar ‘Hyesun’ can be suitable for cultivation in both spring and fall season.

A new lettuce cultivar ‘Misun’ (Lactuca sativa L.) with wrinkled traverse narrow elliptic and deep red leaf, which has late bolting and high yield. It was developed from a cross between ‘Yeoreum Jeocgchima’ (deep red leaf color) and ‘Yeoreum dukseomjeokchukmyeon’ (high yield). The cross and selection for advanced lines had been done by the pedigree method from 2001 to 2008. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) from 2009 to 2011 year. The ‘Misun’ has gray seed color and traverse narrow elliptic leaves. The shelf-life of ‘Misun’ was four weeks longer than ‘Dukseomjeokchukmyeon’ at 4°C. The anthocyanin content of ‘Misun’ (88.32 mg/100 g) was higher than that of ‘Dukseomjeokchukmyeon’(74.78 mg/100g). The BSL (latucin+8-deoxylactucin+lactucopicrin) content of ‘Misun’ (5.0 ug/g, DW) is lower than that of ‘Dukseomjeokchukmyeon’ (12.0 ug/g, DW). Compared to ‘Dukseomjeokchukmyeon’, marketable yield of ‘Misun’(289 g per plant) was 11% higher than that of it, showed good yield in fall season cultivation and has particularly improved expression of red leaf color at high temperature cultivation in the field. Furthermore, its taste is better, more crispy, and sweeter than those of ‘Dukseomjeokchukmyeon’. Thus, this new cultivar ‘Misun’ can be suitable for cultivation in low temperature during spring and fall season season.