The Change Of Selenium Content In Processing Of Wheat And QTL Mapping

Selenium is an essential element for our life. It is significant for improving the body resistance, delaying process of decrepitude, inhibiting tumor and improving human health. In this experiment, Tainong 18, a key breed of wheat promoted in Shandong Province, was used to study the variation of selenium content during wheat processing. At meanwhile, a set of 184 RILs derived from “Tainong 18×Linmai 6” was selected to study QTLs at seedling stage and harvest stage, by adopting hydroponic culture and field trail experiment and combining with high density molecular-marked genetic map. The main results were as follows:1. During wheat processing, Selenium existed mainly in organic form, accounting for 88.4%, 83.1%, 87.4%, 79.2% in gain, flour, wheat bran and steamed bread respectively. Among protein selenium in gain, flour, wheat bran and steamed bread, content of selenium of glutenin is the highest, respective accounting for 16.32%?9.68%?6.55% and 8.39% of the organic selenium.2. Totally 15 QTLs of 4 traits(Rse Ce?SSe Ce?RSe C and SSe C) of Se were mapped at the seedling stage in wheat, spreading on 1A, 2A, 5A, 6A, 1B, 4B, 5B, 6B, 6D and 7D chromosomes. Contribution ratio of individual QTL ranges from 5.38% to 20.22%. Frequency of five QTLs is relatively higher, including QRsece-5B, QSsece-1B, QSsece-5A, QSsece-7D and QSsec-4B, and these QTLs can be detected in two environments or average value. QSsece-7D and QSsec-4B can be detected in two environments or average value, showing that these QTLs has been less influenced by the environment and displayed with finer frequency and better stability.3. Totally 12 QTLs of 4 Se content traits were detected at the seedling stage in wheat, spreading on 4A, 1B, 2B, 3B, 5B, 5D and 7D chromosomes. Contribution ratio of individual QTL ranges from 4.90 to 17.70%. The highest LOD value was 7.96(GSe C). Two relatively high-frequency QTLs(RHF- QTLs) were detected in two environments or average value, including QGsece-5B-2 and QGsec-5B. Among these, QGsec-5B can be detected in two environments and average value, showing that the QTL has been displayed with finer frequency and better stability, which is significant for studying content of selenium in wheat grain at harvest stage.