Genetic Mapping Of QTLs Resistance To Fusarium Head Blight On Chromosome 3B In Wheat L693

Wheat,as major food of one third people in the world,is one of the most important cereals,which can be used to make bread,noodles and cookies for its nutrition value.The production and quality are easily affected by fungal disease,including stripe rust,powdery mildew and Fusarium head blight(FHB).The reduction percent of wheat yield caused by Fusarium head blight is about from 10%to 15%every year;lose can increase to 50%in serious year.Fusarium head blight is also a heavy threat to human beings and animals for the poisonous materials including Deoxynivalenol(DON)and nivalenol(NIV)in infected kernels.The reason of FHB occurrence and prevalence includes two major factors.One major factor is the location,FHB often happened in the middle and low valleys of rivers,such as Yangzi River.The other factor is the weather in wheat heading stage.If wheat occurs to the weather such as high temperature and more rains in flowering stage,FHB will be discovered and prevalent.At present,there is not a good method to control FHB effectively,so developing and breeding a resistance cultivar is the best way to solve the problem,decrease the use of pesticide,and enhance productivity.Nowadays,most of resistance cultivars is derived from Sumai 3,which is universally accepted as the most resistant cultivar to FHB.The resistant resources in wheat is very few,so identifying and screening new materials resistant to Fusarium head blight is our critical work.Besides,the mapping of major QTL is major task in wheat molecular breeding.In this study,we developed a high resistant material L693 and a susceptible material,and used them to create a population F7:8 of 328 recombination inbreed lines derived from single grain.To better value the resistance to FHB,4 graminearum(F4,F15,73,7136)were chose and made of spore suspension to inoculate the middle spikelets(two opposite spikelets)of wheat by single-flower infusion inoculation in 2.years and 2 areas,with the number of diseased spike(NDS)after 14,21,28d inoculation recorded,and the percent of diseased spikelet,disease index and other data on Fusarium head blight calculated.Then,analyzed the molecular marker data,draw a genetic map based on the molecular marker data,and mapped the QTLs on chromosome 3B using Join Map 4.0 and Win QTL Cart.2.5 software.Several conclusions are got below:Firstly,a genetic map on chromosome 3B was constructed,with 27 markers,total length 50.2 cM,which is accurate and reliable after mark partial separation analysis.Secondly,one major QTLs are discovered and agree to the consequence of QTL mapping using population F2.They are located between Xwmc777-3B-2 and Xwmc777-3B-1;the genetic distance is 0.7,which can explain about 18.6%phenotypes variation.Thirdly,two QTLs are detected in different environments.One QTL near Xbarc147-3B marker,may be detected in warm and wet environment during 21 days after flowering state;the other QTL near warkey33-4 marker,can work in cold weather during 21 days after flowering day.Fourthly,the QTL mapped between Xwmc777-3B-2 and Xwmc777-3B-1,is a novel QTL resistant to Fusarium head blight.All results above can put a basic way of fine mapping QTL of resistance to FHB and well promote the process of molecular-assisted breeding.