This study was conducted to determine the physicochemical properties of a giant embryo rice 'P47JB-4-B-5-B' derived from the cross between 'P47', a mutant of 'Hwayoung' induced by T-DNA insertion, and 'Junam'. The grain appearance and chemical components of the embryo were analyzed and compared with a donor cultivar, 'Hwayoung'. The proportion of embryo weight to grain weight of 'P47 JB-4-B-5-B' was 2.2 times heavier (6.7%) than that (3.1%) of 'Hwayoung'. Total free amino acid content (75.81 mg/100 g) of 'P47JB-4-B-5-B' was 2.1 times higher than that of 'Hwayoung'. The GABA content in brown rice was 14.06 mg/100 g in 'P47JB-4-B-5-B' and 6.8 mg/100 g in 'Hwayoung'. Especially, the GABA content in brown rice of 'P47JB-4-B-5-B' remarkably increased (about 33 times from 1.48 mg to 44.81 mg/100 g) 2 days after germination. Continuous frequency distributions and transgressive segregation in embryo length and width were observed in the F2 population of the cross between 'P47' and 'Cheongcheong', indicating that the giant embryo was controlled by quantitative trait loci. However, embryo length and width demonstrated high broad sense heritability, implying that giant embryonic traits could be selected in earlier generations in comparison with other quantitative traits.

Rice is a staple food for more than 50% of the world's population. Embryo comprises only 2 to 3% of the weight distribution of the entire pericarp but has higher concentration of vitamins, proteins, and essential fatty acids than the other parts of grains. Moreover, α-tocoperol, γ-oryzanol, phytic acid and γ-aminobutric acid that have nutraceutical value are abundant. Increasing the volume of embryo assures the fortification of nutritional value of rice grain. We developed new black waxy giant embryo rice, Milyang 263 by crossing Josaengheugchal, a black waxy rice variety, and get, a giant embryo mutant generated by tissue culture. The nutrient contents and physical properties of Milyang 263 were compared with several giant embryo mutants and normal embryo rice varieties. Changes in the nutrient properties after germination were also observed. Results indicated that this new black waxy giant embryo rice, Milyang 263, offers a promising source for improving nutritional quality of rice especially anthocyanin, essential minerals, and GABA.

화청벼 에서 유기된 초거대배 돌연변리계통을 육성하고 그의 미립 외형특성, 단백질함량 및 아미노산 조성, 지질함량 및 지방산 조성, 비타민 함량등의 영양특성 및 작물학적 특성을 원품종과 대비하여 조사하였다 그 결과는 다음과 같다. 1. 초거대배 변리계통의 현미 외형크기는 원품종과 차이가 없었으나, 1000립중은 원품종의 74.5%이었고, 1립당 배의 크기는 건물중으로 322%이었다. 2. 현미의 단백질함량은 8.99%로 화청벼의 7.39%에 비해 높았고, 저장단백질의 조성은 차이가 없었다. 아미노산조성에서는 현미 전체로 볼 때 lysine 함량이 월등히 증대되었고, methionine, serine, ,tyrosine 함량이 다소 감소되었다. 3. 현미의 지질함량은 5.7%로 원품종의 3.8%에 비해 1.5배 증가하였다. 지방산 중 팔미틴 산 함량은 증가하였고, 리놀산 함량은 감소하였다. 4. 배의 비타민 B1,B2 , niacin함량에서 초거대배미와 원품종과는 차이가 없었으며, α-tocopherol 함량은 감소하였으나, 현미 전체로 보면B1,B2 , α-tocopherol 함량이 월등히 증가하였다. 5. 초거대배미는 고영양미로서의 이용가치가 클것으로 판단되었다. 6. 초거대배 변이계통(M4)들의 정조수량은 원품종인 화청벼(556kg/10a)에 비해 69.2～78.8% 정도이었다. 생육형질의 변이계수로 보아 대부분 계통들이 고정된 것으로 나타났다.