芥菜型油菜黄黑种皮多酚差异的紫外-可见光谱研究

以芥菜型自交系黄黑油菜种皮为材料，研究了其多酚提取液的紫外-可见吸收光谱， 测定了芥菜型油菜黄黑种皮样以没食子酸和茶儿茶素标准计的多酚含量，发现黄种皮的多酚含量约为黑种皮的90%，显著区别于甘蓝型油菜的10%，因此多酚含量高可能是芥菜型黄籽油菜性状稳定的根本内因。基于香草醛试验，推测黑种皮中含有3-OH的黄烷醇类多酚，而黄种皮中没有。基于加入位移试剂后特征吸收谱带Ⅰ与Ⅱ的位移方向与大小，推测黄酮醇类多酚A环在黄种皮中可能主要为单酚羟基，而在黑种皮中可能主要为邻二酚羟基结构。这种多酚分子的结构差异可能是形成芥菜型油菜黄黑种皮色泽差异的主要原因。

UV-Vis Spectrum Differences of Polyphenols between Yellow and Black Seed Coats of Brassica juncea

The seed coat color has been thought to be closely concerned in the polyphenols. The content differences of polyphenols between yellow and black seed coats have been determined in Brassica napus, but not in Brassica juncea. In addition， the molecular structure differences of polyphenols between yellow and black seed coats seem not to be reported in Brassica. Plant polyphenols are a large number of complex compounds containing hydroxyls, they play an important role in physiological actions in plant organism. To find out the content differences and the molecular structure differences of polyphenols between yellow and black seed coats, and the relationship between the polyphenols’ differences and the seed coat color differences in B. juncea the yellow and black seed coats of inbred lines of B. juncea were used as the research materials， the solutions of the polyphenols extracted from the yellow and black seed coat samples with 5% HCl-CH3OH were scanned by the UV-Vis spectrophotometer(UV-1600) at wavelength of 200–300/800 nm, and the contents of polyphenols were determined through absorption spectrometry with either gallic acid or tea catechin standard， respectively. The results showed that the content of polyphenols of the yellow seed coat was about 90% of that of the black seed coat. While the content of polyphenols of the yellow seed coat was about 10% of that of the black seed coat in B. napus. Therefore the high content of polyphenols might be the main factor resulting in the character heredity stability of yellow rapeseed in B. juncea. In vanillin test the black seed coat turned red in color， the yellow coat remained the original color. It could be deduced that there are the flavanol-phenolic molecules that their ring C should contain 3-OH among the polyphenols of the black seed-coat, while there are not these molecules among the polyphenols of the yellow seed-coat. After the shift reagents were added in the solutions of the polyphenols extracted from the yellow and the black seed-coats， the spectral absorption band Ⅰ&;Ⅱ shifted. On basis of the shift direction and the shift quantity of the spectral band Ⅰ&;Ⅱ it could be deduced that phenolic ring A of the flavanol-phenolic molecules might contain monohydroxyl (7-OH) and o-dihydroxyl among the polyphenols of the yellow and the black seed-coats, respectively. It is proposed that the structural differences of the polyphenols might be the major factor resulting in the color differences between the yellow and the black seed coats in B. juncea. These results above may be significant not only in the yellow rapeseed breeding in B. juncea but also in trying to solve the unstable character heredity of the yellow rapeseed in B. napus.