Abstract
As one of the major storage carbohydrates, starch correlates with the tissue firmness and cell wall contents as well as contributes to the textural quality of radish (Raphanus sativus L.) root. In this study we developed a simple method to evaluate starch content and tissue firmness by measuring the color (Hunter 'b') of iodized radish slice as a starch index. The gelatinization of radish slice was optimized by swelling at 60${^{\circ}C}$ for 20 min, and the Hunter 'b' value and the concentration of iodized potato starch were highly correlated (r$^{2}$=0.948). This relationship was also effective to the analyses of inheritable texture traits of three F1 hybrids and their breeding lines. The heritability of tissue firmness of radish root, based on starch index and compressibility, turned out to be fairly high, ranging from 0.47 to 0.93. However, heterosis was relatively low. This method is simple and rapid, and, therein, could be employed as a quick evaluation for qualifying radish texture since the correlation between Hunter 'b' value and starch content was consistent among different cultivars. The present study also revealed that either parental line which exhibits a relatively less firm in texture of the root was dominant.
본 연구에서는 전분-요오드반응을 적용하여 무 조직의 Hunter 'b' 값을 측정하여 전분 지수(starch index)를 구하고, 이를 통해 전분 함량과 경도를 간편하게 평가하는 방법을 개발하였다. 무 조직의 호화조건은 60${^{\circ}C}$에서 20분 이상 침지하는 것이 요오드 반응에 가장 효과적이었으며, 색차계를 이용한 Hunter 'b' 값은 전분 농도와 고도의 역의 상관관계를 보였다(r$^{2}$=0.948). 이를 토대로 비교했을 때 일대 잡종 무조직의 색도와 경도는 품종간에도 고도의 상관을 나타내어(r$^{2}$=0.703) 무의 조직감을 비교하는 지표로 활용할 수 있었다. 또한 일대 잡종 무와 양친, 여교잡 세대 및 후대를 대상으로 조직의 전분 지표를 측정한 결과, 양친 중 무의 조직감이 낮은 쪽이 우성으로 작용하며, 잡종 강세가 약하게 나타나는 형질인 것으로 나타났다.