Recombinats Analysis Of FHB1:Amajor Gene Controlling Fusarium Head Blight Resistance

Fusarium head blight (FHB) is an important disease to wheat production globally. It affects the yield and quality of wheat seriously. Discovery and application of the FHB resistance gene is the main method of controlling FHB. Fhb1 is a major QTL for FHB resistance on chromosome 3BS, which exists in many FHB resistant germplasms such as Sumai3 and Wangshuibai.In the previous study, with the help of molecular markers assisted selection, Fhbl near isogenic lines (NILs) of Wangshuibai and Sumai3 were developed, using PH691 and Mianyang99-323 as recurrent parents. Using the Nanda2419 x Wangshuiba RILs population and a secondary population derived from the cross of Fhb1 NIL and the recurrent parent Mianyang 99-323, Fhbl was fine mapped to a 0.3cM interval flanked by Xmag8620 and Xmag8937. Since no more recombination types were found in these populations, it was difficult to map Fhb1 to a smaller interval. To fine map Fhbl,38 molecular markers was newly developed based on the Wangshuibai BAC clone sequence and homology sequence of Fhbl from Chinese Spring in this study. Furthermore a high-resolution map of Fhb1 interval was finally constructed using a secondary F2 population derived from Fhbl NIL and its recurrent parent PH691. This map comprises 12 polymorphic markers and span 3.1 cM with a marker density of 0.26 cM/marker.The Fhbl RIL recombinants derived from Wangshuibai xNanda 2419 was genotyped with the newly developed markers. Combined the genotype and phenoty ofthese recombinants, Fhbl was fine mapped to the Xmag8937-Xmag8620 interval. Plants with recombination occurring within Fhb1 interval were identified in F2,3 populations derived from the cross of the recurrent parent PH691 and Fhbl NILs from wangshuibai or Sumai3, using the flanking markers BARC147 and CFB6072.211 recombinants including 9 recombination types were found from Wangshuibai and 47 recombinants including 8 recombination types was found from Sumai3. Combined with the phenotype dater Fhbl was fine mapped to a 0.2 cM interval flanked by Xmag8937 and Xwgrb0011. The Fhb1 interval mapped using the above-mentioned three populations overlapped each other.