Abstract:

Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is an important wheat disease world-wide. Negative effects of the disease include not only reduction of grain yield quality, but also contamination with deoxynivalenol (DON) resulting in potential toxicity to human and livestock. Developing the cultivars with FHB resistance is an effective measure to control the disease. Ten cultivars selected from the breeding program for FHB resistance in China were employed in the study for evaluating the resistance to FHB and DON accumulation by using different isolates and inoculation methods. In comparing with susceptible control Ningmai 6 and Annong 8455, the ten cultivars were classified to three groups with different resistance to FHB, including high resistant group (Wangshuibai, Sumai 3, Nobeokoubozu and Fan 60096), moderate resistant group (Fanshanxiaomai, Wenzhouhongheshang, Shinchunaga, Yangmai 158 and Zhen 7459) and susceptible cultivar (Frontana). The DON contents of all of them except Frontana were lower than 3 mg/kg. There were significant correlations between different isolates and inoculation methods for the scabbed spikelet rate and DON content. The scabbed spikelet rate was also significantly correlated to DON content in the same isolate and inoculation method. The selective cultivars were genotyped with SSR markers linked to FHB resistance QTL on chromosomes 2D, 3B, 4B, 5A and 6B identified previously. The SSR markers except GWM133 from 4B chromosome had PIC values of 0.14 to 0.85 and detected 2 to 8 alleles among 13 cultivars. The haplotype showed the same allele of related SSR on chromosome 3B was shared by Nobeokabouzu and Wangshuibai. Yangmai 158 and Shinchunaga had similar SSR alleles to Wuhan 1 on chromosomes 2D and 4B, respectively. Most alleles from Fanshanxiaomai were the same as those from Sumai 3 or Wangshuibai. Most alleles of SSR related to QTL on 2D from Fan 60096 were similar to those from Wuhan 1. However, only one or two alleles in Zhenmai 7459 and Wengzhouhongheshang were the same as those of reported SSR markers associated with FHB resistance. The resistances in such cultivars are most likely derived from independent origin instead of Sumai 3, Wangshuibai and Wuhan 1.

Key words: Triticum aestivum L., Fusarium head blight, Deoxynivalenol (DON), SSR