Studies On Pyramid Breeding And Backcross Breeding Of Thefusarium Head Blight-resistant Transgenic Wheat

Fusarium head blight(FHB) mainly caused by Fusarium graminearum is a devastating disease of wheat(Triticum aestivum L.) worldwide. it not only cause wheat seedling rot and ear rot resulting in yield loss, but also produce toxins which bring a serious threat to food safety and health of human and animal. The absence of a monogenic source of resistance against FHB and lack of host resistance to FHB in wheat makes it more difficult breeding new varieties with both high FHB resistance and good agronomic traits. Through polymerization breeding and backcross breeding technology, researchers can use transgenic plants with different resistance genes to acquire multiple resistant genes and transgenic excellent agronomic traits strains. That is an effective way to breed new FHB resistance wheat varieties.In this study, we used different FHB resistance transgenic wheat lines which have been obtained in our laboratory, expect to acquire FHB resistance wheat lines through polymerization breeding and backcross breeding technology. The main results are as follows:1. Through polymerization breeding technology, we obtained 9 transgenic polymeric materials.Combination 1: C331 Zhengmai 9023(Ech42) × E112 Zhengmai 9023(VP1, Basi, AFP2);Combination 2: C331 Zhengmai 9023(Ech42) × H16 Yangmai 158(Chi);Combination 3: C343 Zhengmai 9023(Ech42) × E112 Zhengmai 9023( VP1, Basi,AFP2);Combination 4: C343 Zhengmai 9023(Ech42) × B50 Zhengmai 9023(NPR1);Combination 5: C367 Yangmai 158(Zm GC, Ech42, ACE) × H16 Yangmai 158(Chi);Combination 6: C367 Yangmai 158(Zm GC, Ech42, ACE) × C331 Zhengmai 9023(Ech42);Combination 7: C367 Yangmai 158(Zm GC, Ech42, ACE) × B50 Zhengmai 9023(NPR1);Combination 8: C462 Zhengmai 9023(UEch42, Hv Chi D2) × B50 Zhengmai 9023(NPR1);Combination 9: D79 Yangmai 11(Rs D2-Msr A1) × G80 Yangmai 158(NPR1).These different combinations of F4 generations were identified by single flower inoculation. Results showed that the FHB resistance level of the majority of these combinations was increased, and the following genotypes increased significantly. Combination 2(C331 × H16), Combination 5(C367 × H16), Combination 6(C367 × C331) disease rate fell by 49.27%, 46.32%, 39.90% compared with the recipient parent Yangmai 158, respectively. Combination 8(C462 × B50) disease rate fell by 38.66% compared with the recipient parent Yangmai 158.2. Different FHB resistance transgenic wheat materials were used as backcross parents, and offspring of BC2F1 were obtained now. A total of 40 backcross breeding lines of Xiangmai 11, Xiangmai 13, Xiangmai 16, Xiangmai 26, Xiangmai 27, Xiangmai 32, Xiangmai 76, G237 and G125. Lines 76, G237 and G125 were acquired.These different combinations of BC3F1 generations were identified by single flower inoculation. Results showed that the FHB resistance level of the majority of these combinations was increased, and the following 5 genotypes increased significantly.① The combination of Xiangmai 11×Line A9(Yangmai11: RSD2-NPR1-Msr A1)disease rate fell by 43.82% compared with the recurrent parent Xiangmai 11.② The combination of Xiangmai 26×Line A6(Yangmai 11: Msr A1) disease rate fell by 52.58% compared with the recurrent parent Xiangmai 26.③ The combination of Xiangmai 32×Line A6(Yangmai 11: Msr A1) disease rate fell by 53.81% compared with the recurrent parent Xiangmai 32.④ The combination of Xiangmai 76×Line A8(Yangmai 11: RSD2-NPR1) disease rate fell by 71.27% compared with the recurrent parent Xiangmai 76.⑤ The combination of Xiangmai 76×Line A5(Yangmai 11: NPR1) disease rate fell by 57.69% compared with the recurrent parent Xiangmai 76.