A single recessive gene, rxp, controls the bacterial leaf pustule (BLP) resistance in soybean and in our previous article, it has been mapped on linkage group (LG) D2 of molecular genetic map of soybean. A total of 130 recombinant inbred lines (RILs) from a cross between BLP-resistant SS2-2 and BLP-susceptible Jangyeobkong were used to identify molecular markers linked to rxp. Fifteen simple sequence repeat (SSR) markers on LG D2 were screened to construct a genetic map of rxp locus. Only four SSR markers, Satt135, Satt372, Satt448, and Satt486, showed parental polymorphisms. Using these markers, genetic scaffold map was constructed covering 26.2cM. Based on the single analysis of variance, Satt372 among these four SSR markers was the most significantly associated with the resistance to BLP. To develop new amplified fragment length polymorphism (AFLP) marker linked to the resistance gene, bulked segregant analysis (BSA) was employed. Resistance and susceptible bulks were made by pooling equal amount of genomic DNAs from ten of each in the segregating population. A total of 192 primer combinations were used to identify specific bands to the resistance, selecting three putative AFLP markers. These AFLP markers produced the fragment present in SS2-2 and the resistant bulk, and not in Jangyeobkong and the susceptible bulk. Linkage analysis revealed that McctEact97 (P=0.0004,~;R2=14.67~%) was more significant than Satt372, previously reported as the most closely linked marker.

A new vegetable peanut variety “Bakjung(Arachis hypogaea L.)” was developed from the cross between Shindaekwang and Suwon94 at the Honam Agricultural Research Institute and Yongnam Agricultural Research Institute, National Institute of Crop Science in 200

A new sprout-soybean variety, “Dagi” was developed from the cross between Namhaekong and D70-6545 by the soybean breeding laboratory of the National Honam Agricultural Experiment Station (NHAES) in 2002. The preliminary, advanced, and regional yield trial

Two important loci, designated Rhg1 and Rhg4, are responsible for most resistance to soybean cyst nematode (SCN). The objective of this study was to survey single nucleotide polymorphism (SNP) and to map the SCN-resistant gene, Rhg4, on soybean genetic ma

Somaclonal variation, defined as phenotypic and genetic variations among regenerated plants from a parental plant, could be caused by changes in chromosome structure, single gene mutation, cytoplasm genetic mutation, insertion of transposable elements, and DNA methylation during plant regeneration. The objective of this study was to evaluate DNA variations among somaclonal variants from the cotyledonary node culture in soybean. A total of 61 soybean somaclones including seven ~textrmR1 lines and seven ~textrmR2 lines from Iksannamulkong as well as 27 ~textrmR1 lines and 20 ~textrmR2 lines from Jinju 1 were regenerated by organogenesis from the soybean cotyledonary node culture system. Field evaluation revealed no phenotypic difference in major agronomic traits between somaclonal variants and their wild types. AFLP and SSR analyses were performed to detect variations at the DNA level among somaclonal variants of two varieties. Based on AFLP analysis using 36 primer sets, 17 of 892 bands were polymorphic between Iksannamulkong and its somaclonal variants and 11 of 887 bands were polymorphic between Jinju 1 and its somaclonal variants, indicating the presence of DNA sequence change during plant regeneration. Using 36 SSR markers, two polymorphic SSR markers were detected between Iksannamulkong and its somaclonal variants. Sequence comparison amplified with the primers flanking Satt545 showed four additional stretches of ATT repeat in the variant. This suggests that variation at the DNA level between somaclonal variants and their wild types could provide basis for inducing mutation via plant regeneration and broadening crop genetic diversity.

Genetic diversity and soybean sprout-related traits were evaluated in a total of 72 soybean accessions (60 Glycine max, 7 Glycine soja, and 5 Glycine gracilis). 100-seed weight (SW) was greatly varied and ranged from 3.2g to 32.3g in 72 soybean accessions. Positive correlation was observed between GR and hypocotyl length (HL), whereas negative correlation was observed between SW and hypocotyl diameter (HD). Re-evaluation by discarding two soybean genotypes characterized with low GR indicated that much higher correlation of sprout yield (SY) with HD and SW. Based on the principal component analysis (PCA) for sprout-related traits, 57 accessions were classified. Soybean genotypes with better traits for sprout, such as small size of seeds and high SY, were characterized with high PCA 1 and PCA 2 values. The seed size in second is small but showed low GR and SY, whereas the third has large seed, high GR and more than 400% SY. In genetic similarity analysis using 60 SSR marker genotyping, 72 accessions were classified into three major and several minor groups. Nine of twelve accessions that were identified as the representatives of soybean for sprout based on PCA were in a group by the SSR marker analysis, indicating the SSR marker selection of parental genotypes for soybean sprout improvement program.

Danok3, a sweet corn hybrid that matures early was developed by the corn breeding team at the National Crop Experiment Station (NCES), RDA in 2001. Inbred KSS2 derived from Golden Bantam was used as the seed parent of Danok3, and inbred KSS22 derived from

Lipoxygenase might be associated with seed deterioration by catalyzing the incorporation of molecular oxygen into fatty acids and generating free radicals. This study was performed to determine whether seed lipoxygenase activity would alter soybean seed longevity. In this study, germination percentage of lipoxygenase-lacking cultivar Jinpumkong2 (lx1lx1lx2lx2lx3lx3) was lower than that of Taekwangkong (Lx1Lx1Lx2Lx2Lx3Lx3). Segregation ratio for the three lipoxygenase isozymes of the F2-derived from the cross between Taekwangkong and Jinpumkong2 was fitted to 9 (Lx1Lx2Lx3) : 3 (Lx1Lx2lx3) : 3 (lxllx2Lx3) : 1 (lx1lx2lx3), suggesting the tight linkage between the Lx1 and Lx2 loci. Germination percentages varied widely but not differed among lipoxygenase isozyme types of F3 seeds before and after accelerated aging. Seed coat of Jinpumkong2 was damaged severely following accelerated aging, whereas that of Taekwangkong was not. Thus, seed of lipoxygenase-lacking soybean cultivar, Jinpumkong2 showed greater deterioration compared with that of the normal Taekwangkong. However, the presence or absence of lipoxygenase activity had no effect on soybean germination

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.