콩에 함유된 성분 중 가장 많은 양으로 존재하며, 인축의 주요 단백질 공급원으로 이용되고 있는 콩 단백질의 함량을 1립 비파괴 근적외 분광분석법을 이용하여 동일품종의 개체 내에서 콩이 달린 착협 위치에 따라, 또 콩에서 단백질 함량을 분석하기 위해 개체 내에서 분석시료를 취할 때 개체를 대표할 수 있는 최소 양을 실험적으로 검토한 결과를 요약하면 다음과 같다. 1. 선녹콩 개체 내 단백질 함량은 정규분포를 보였으며, 개체 간에 단백질 함량의 차이가 인정되었다. 2. 콩의 착협 위치에 따른 단백질 함량은 지표면에 가까울수록 단백질 함량이 높았고, 콩 식물체의 윗부분으로 갈수록 단백질 함량이 낮아지는 경향을 나타내었다. 3. 콩에 함유된 단백질의 함량을 정량적으로 분석하기 위해 필요한 최소 시료량을 추정한 결과 최소 10립 이상 혹은 개체 내 총 종자량의 20% 이상을 취하면 개체를 대표하는 단백질 함량을 얻을 수 있는 것으로 조사되었다.
Soybean [Glycine max (L.)] is a major source of protein for human and animal feed. Inter- and intra-genotype variation of soybean protein has been investigated by soybean researchers. However, limited sample amount of soybean single seed there is no report that investigated intra-plant variation of soybean protein within soybean plant. Recently a non-destructive NIR (near-infrared reflectance) spectroscopy using single seed grain to analyze seed protein was developed. The objectives of this study were to understand variation of seed protein content within plant and to determine the amount of minimum sample size which can represent protein content for a soybean plant. Frequency distribution of protein content within plant showed normal distribution. There was an intra-cultivar variation for protein content in soybean cultivar Seonnogkong. Difference of protein content among single plants of Seonnokong was recognized at 5% level. Seeds in lower position on plant stem tended to accumulate more protein than in higher position. There was significant difference for protein content between sample size 5 seeds and sample size of more than 5 seeds (10, 20, 30, 40, and 50 seeds) at a soybean plant with 57 seeds however no difference was recognized among sample size (5, 10, 20, and 30 seeds) at a soybean plant with 33 seeds. Around 20% seeds of soybean from single plant needed to determine the protein content to represent protein content of single soybean plant. This study is the first one to report evidence of intra-plant variation for proteincontent which detected by non-destructive NIR spectroscopy using single seed grain in soybean.