• Journal of Life Science
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• v.33 no.8
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• pp.632-638
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• 2023

A soybean cultivar with a green seed coat and cotyledon contains high levels of lutein, which is beneficial for eye health. Plus, antinutritional components such as lipoxygenase, Kunitz trypsin inhibitor (KTI), lectin and stachyose exist in the mature seed. The genetic elimination of these antinutritional factors is a necessary step in green soybean breeding. This research was conducted to improve a new green soybean line with the green cotyledon and tetra null genotype (lox1lox2lox3tilers2) in terms of lipoxygenase, KTI, lectin and stachyose. We used five germplasms to develop a breeding population. A total of 69 F₂ seeds were obtained from the cross of parent 1 and parent 2, and from those, 21 F₂ seeds were selected that had the green seed coat color, and which were free of lectin protein. Next, four F₂ plants with the green seed coat and tetra null genotype were selected from the breeding population derived from four genotypes. The absence of lipoxygenase, KTI and lectin proteins was confirmed in the F₅ strain. The breeding line has a green seed coat, green cotyledon and white hilum color. The 100-seed weight and stachyose content for the breeding line were 30.7 g and 2.40 g/kg, respectively. The line selected in this study could be used as a cultivar or parent to improve colored soybean cultivars through the removal of antinutritional components such as lip- oxygenase, KTI, lectin and stachyose.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.114-120
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• 2023

Soybean is the one of the most important crops for providing quality vegetable protein to umans and livestock. Soybean cultivars with a brown seed coat have a wide range of antioxidant benefits because of the flavonoid components. However, they also contain lectin, 7S α′ subunit, lipoxygenase, and Kunitz trypsin inhibitor (KTI) proteins that can be allergenic and digestive inhibitors and reduce processing aptitude. Genetic removal of these four proteins is necessary in soybean breeding. Therefore, this study was conducted to select a new line with brown seed coat, green cotyledon, and tetra-null genotype (lecgy1lox1lox2lox3ti) for lectin, 7S α′ subunit, lipoxygenase, and KTI proteins in the mature seed. Five germplasms were used to create breeding population. From a total of 58 F₂ plants, F₂ plants with lele genotype were selected using a DNA marker, and F₃ seeds with a brown seed coat, green cotyledon, and the absence of 7S α′ subunit protein were selected. Three lines (S1, S2, and S3) were developed. Genetic absence of lectin, 7S α′ subunit, lipoxygenase, and KTI proteins was confirmed in F₆ seeds of the three lines, which had a brown seed coat, green cotyledons, and a white hilum. The 100 seed weights of the three lines were 26.4-30.9 g, which were lower than 36 g of the check cultivar - 'Chungja#3'. The new S2 line with 30.9 g hundred seed weight can be used as a parent to improve colored soybean cultivars without antinutritional factors such as lectin, 7S α′ subunit, lipoxygenase, and KTI proteins.