不同发芽时间下发芽稻谷和糙米不同部位γ-氨基丁酸含量差异

选用云南和浙江近期育成的γ - 氨基丁酸(GABA)含量差异较大的水稻品种(系)26 个，在云南新平相同栽培条件下种植，比较研究其稻谷和糙米不同发芽时间对不同部位GABA 含量累积的差异。结果表明：供试26 个品种(系)以滇农S-1/ 滇靖8 号、HIPj1、文稻1 号/IR36、和文稻2 号/IR36 四个品种(系)GABA 含量最高；萌发前GABA 含量各部位依次为皮胚＞颖壳＞糙米＞精米。萌发活化24～28h 能显著促进萌发稻谷和糙米中GABA 含量的累积，呈现先升高后降低的变化趋势，尤其是糙米在萌发后24h 达到最高峰值。稻谷和糙米萌发后不同的部位GABA 的累积速率和累积量不同，各部位GABA 含量依次为：胚芽＞糙米＞精米，颖壳最低；萌发活化后GABA含量累积呈现糙米大于稻谷；胚芽中GABA 含量粳稻高于籼稻。

Changes in Gamma-Aminobutyric Acid Content in Different Parts of Rice and Brown Rice during Germination

The content of γ-aminobutyric acid (γ-GABA), one of the main functional components in rice, changes with the parts and the germination periods of rice. This study aimed to analyze the changes in γ-GABA content in differert parts of rice and brown rice of 26 varieties (containing 12 japonica varieties and 14 indica varieties) that have been recently bred in Yunnan province or Zhejiang province and were grown in Xinping county in Yunnan province during germination. The results showed that Diannong S-1/Dianjing 8, HIPj 1, Wendao1/ IR 36 and Wendao 2/IR 36 had the highest γ-GABA content among the 26 rice varieties; the γ-GABA contents in different parts of rice before germination decreased in the following order: rice germ ＞ rice husk ＞ brown rice ＞ polished rice; the germination activation for 24－28 h could significantly promote the accumulation of γ-GABA in rice and brown rice, showing a trend of first increase and then decrease, and the γ-GABA content in brown rice reached maximum at 24 h of germination; the accumulation rate and quantity in different parts of germinated rice and germinated brown rice were different, and the γ-GABA contents in different parts decreased in the following order: rice germ ＞ brown rice ＞ polished rice ＞ rice husk; after germination activation, the γ-GABA accumulation quantity in brown rice was more than that in rice, and the average content of γ-GABA in rice germ of 12 japonica varieties was higher than that of 14 indica varieties.