‘Hogammi’ was developed as a sweetpotato variety with β-carotene content and excellent palatability in 2015. It was derived by crossing ‘AB95007-2’, which has good shape and storage root yield, and ‘Annoimo’, which has light orange flesh and good palatability. ‘Hogammi’ had storage roots with long elliptical shape, red skin, and light orange flesh. The texture of the steamed storage root of ‘Hogammi’ was intermediate or slightly moist, and it was more tender than that of ‘Yulmi’. The soluble solid content of the steamed storage roots of ‘Hogammi’ was 29.7 °Brix, which was 10.8% higher than that of ‘Yulmi’. The palatability of the steamed storage roots of ‘Hogammi’ was better than that of ‘Yulmi’. The β-carotene content of the storage roots of ‘Hogammi’ was 9.8 mg/100 g dry weight. ‘Hogammi’ was moderately resistant to Fusarium wilt and root-knot nematode. In ‘Hogammi’, the number of marketable storage roots per plant and the average weight of marketable storage root were 3.4 and 133 g under culture in the normal season, respectively. The marketable storage root yield of ‘Hogammi’ was 24.1 MT/ha under culture in the normal season, which was 4% higher than that of ‘Yulmi’. The yield of marketable storage root over 50 g of ‘Hogammi’ was 14.5 MT/ha under culture in the early season, which was 39.8% lower than that under culture in the normal season. ‘Hogammi’ was more suitable for culture in the normal season (Registration No. 6466).

The β-carotene biofortified transgenic soybean was developed recently through Agrobacterium-mediated transformation using the recombinant PAC (Phytoene synthase-2A-Carotene desaturase) gene in Korean soybean (Glycine max L. cv. Kwangan). GM crops prior to use as food or release into the environment required risk assessments to environment and human health in Korea. Generally, transgenic plants containing a copy of T-DNA were used for stable expression of desirable trait gene in risk assessments. Also, information about integration site of T-DNA can be used to test the hypothesis that the inserted DNA does not trigger production of unintended transgenic proteins, or disrupt plant genes, which may cause the transgenic crop to be harmful. As these reasons, we selected four transgenic soybean lines expressing carotenoid biosynthesis genes with a copy of T-DNA by using Southern blot analysis, and analyzed the integration sites of their T-DNA by using flanking sequence analysis. The results showed that, T-DNA of three transgenic soybean lines (7-1-1-1, 9-1-2, 10-10-1) was inserted within intergenic region of the soybean chromosome, while T-DNA of a transgenic soybean line (10-19-1) located exon region of chromosome 13. This data of integration site and flanking sequences is useful for the biosafety assessment and for the identification of the β-carotene biofortified transgenic soybean.

The β-carotene biofortified transgenic rice was developed by transforming rice cv. Nakdongbyeo with phytoene synthase (Psy) and carotene desaturase (Crt I) genes isolated from Capsicum and Pantoea. The aim of this study was to perform molecular characterization of rice transformants of T5-T7 generation harboring Psy and Ctr I genes driven by endosperm specific globulin promoter for biosafety evaluation of β-carotene biofortified transgenic rice. The structure and sequence of T-DNA in the transformation vector and the insertion sites, flanking sequences and generational stability of inserted T-DNA in transgenic rice lines were analyzed. The transformation vector consisted of right border, MAR gene, carotenogenic genes unit, herbicide resistance selectable marker unit, MAR gene and left border in sequential order. T-DNA was introduced at the position of 30,363,938-30,363,973 bp of chromosome No. 2 by adaptor-ligation PCR. Stable integration of T-DNA and stable expression of bar gene was confirmed in T5 to T7 generations. It was also confirmed that the backbone DNA of transformation vector containing antibacterial gene was not present in the genome of β-carotene biofortified transgenic rice. HPLC analysis confirmed that carotenoids were consistently detected through T5-T7 generations.