Integration of meta-QTL discovery with omics: Towards a molecular breeding platform for improving wheat resistance to Fusarium head blight

Fusarium head blight(FHB) is a global wheat disease that devastates wheat production. Resistance to FHB spread within a wheat spike(type Ⅱ resistance) and to mycotoxin accumulation in infected kernel(type Ⅲ resistance) are the two main types of resistance. Of hundreds of QTL that have been reported, only a few can be used in wheat breeding because most show minor and/or inconsistent effects in different genetic backgrounds. We describe a new strategy for identifying robust and reliable meta-QTL(mQTL)that can be used for improvement of wheat FHB resistance. It involves integration of mQTL analysis with mQTL physical mapping and identification of single-copy markers and candidate genes. Using metaanalysis, we consolidated 625 original QTL from 113 publications into 118 genetic map-based mQTL(gmQTL). These gmQTL were further located on the Chinese Spring reference sequence map. Finally, 77 high-confidence mQTL(hcmQTL) were selected from the reference sequence-based mQTL(smQTL).Locus-specific single nucleotide polymorphism(SNP) and simple sequence repeat(SSR) markers and17 genes responsive to FHB were then identified in the hcmQTL intervals by combined analysis of transcriptomic and proteomic data. This work may lead to a comprehensive molecular breeding platform for improving wheat resistance to FHB.

Methylselenized glucose:An efficient organoselenium fertilizer enhancing the selenium content in wheat grains

Selenium(Se)is an essential mineral element for human and other animals,and has been proved to improve plant growth and development and tolerance to different abiotic stresses.Selenium biofortification is considered to be a key strategy to increase the selenium content of edible parts of crops,which is helpful for improving human health.In this work,foliar fertilization with different concentrations and selenium forms was carried out on two wheat varieties at the flowering stage to compare the selenium enrichment effect of Na_(2)SeO_(3),methylselenized selenocysteine(MSC),methylselenized glucose(MSG)and methylselenized lactide(MSL)in wheat grains.Surprisingly,MSG was found to be the preferable fertilizer.After the application of MSG,the highest selenium content in wheat gains reached 6 mg/kg in this experiment,and the average selenium content was 2-4 times versus that of Na_(2)SeO_(3)application.Since MSG has high utilization rate and is easily available at relatively low cost,it can be employed as a potential selenium source for selenium biofortification to enhance the added value of agricultural industry.