The areas of soybean (Glycine max (L.) Merrill) cultivation in Gangwon-do have increased due to the growing demand for well-being foods. The soybean barcode system is a useful tool for cultivar identification and diversity analysis, which could be used in the seed production system for soybean cultivars. We genotyped cultivars using 202 insertion and deletion (InDel) markers specific to dense variation blocks (dVBs), and examined their ability to identify cultivars and analyze diversity by comparison to the database in the soybean barcode system. The genetic homology of “Cheonga,” “Gichan,” “Daewang,” “Haesal,” and “Gangil” to the 147 accessions was lower than 81.2%, demonstrating that these barcodes have potentiality in cultivar identification. Diversity analysis of one hundred and fifty-three soybean cultivars revealed four subgroups and one admixture (major allele frequency <0.6). Among the accessions, “Heugcheong,” “Hoban,” and “Cheonga” were included in subgroup 1 and “Gichan,” “Daewang,” “Haesal,” and “Gangil” in the admixture. The genetic regions of subgroups 3 and 4 in the admixture were reshuffled for early maturity and environmental tolerance, respectively, suggesting that soybean accessions with new dVB types should be developed to improve the value of soybean products to the end user. These results indicated that the two-dimensional barcodes of soybean cultivars enable not only genetic identification, but also management of genetic resources through diversity analysis.

Knowledge of the chromosomal constitution of the ancestors of modern soybean will complement plant breeding efforts to improve agronomic and economic characteristics of soybean. Variation block (VB)-based comparison using genome-wide insertion/deletion (InDel) markers was used on a diverse panel of 147 soybean cultivars to assess the impact of chromosomal changes during modern breeding. There were identical variation patterns of the examined InDels consistently appearing in the genome parts arising from parental varieties, indicating that soybean chromosomes in descendants should be all determined by genetic reshuffling of VBs inherited from parental chromosomes. Structure analysis of the accessions through the 202 InDels separated the accessions into four subgroups. Gene introgression revealed by the structure analysis agreed with the fact that a limited number of landraces and elite varieties were introduced and used as donors for breeding soybean cultivars in pedigree analysis. Especially, VBs became more reshuffled over time as a result of the breeding process, which resulted in using breeding parents with new VB-types for improving the end-use value of soybean. Therefore, their clustering using the 202 VB-specific InDels is strongly influenced by the difference in breeding ancestors among the subgroups. This indicates that the 202 InDel markers are very useful for genetic study by analyzing the reshuffling patterns of the parental genomes in the descendant.

This study was carried out to establish the optimal conditions for callus induction and plant regeneration using immature inflorescence of M. sacchariflorus cv. ‘Wooram’, a bioenergy crop selected in Korea. Callus induction rate was the highest (93.3%) in MS medium containing 3 mg L^-1 2,4-D, and 86.7% in MS medium containing 3 mg L^-1 2,4-D combined with 0.1 mg L^-1 BA. Plant regeneration rate was high when the calli derived from the medium containing BA was used, as compared with those derived from the BA-minus medium. The results showed that the medium conditions containing 5 mg L^-1 BA combined with 0.1 mg L^-1 NAA was the most effective in plant regeneration of which the rate reached 86.7%. The regenerated shoots were separated from the calli and roots over 3 cm were developed from the shoots after 4 week culture on basal MS medium without supplementation. The plantlets were then transferred to soil and cultured in greenhouse. After 5 weeks, the plants with the height of at least 20 cm were successfully acclimatized.