ARS | Publication request: Identification of chromosomes responsible for crown rot resistance in durum wheat

Submitted to: International Wheat Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 15, 2008
Publication Date: August 24, 2008
Citation: Zheng, Z., H.B. Li, J. Ma, S. Chakraborty, J.D. Faris, S.S. Xu, and C.J. Liu. 2008. Identification of chromosomes responsible for crown rot resistance in durum wheat. In: R. Appels, R. Eastwood, E. Lagudah, P. Langridge, M. Mackay, L. McIntye, and P. Sharp (Eds.) Proc. 11th Wheat Genet. Symp., vol. 3. Sydney University Press, Sydney, Australia. Pp 770-772.

Technical Abstract: Crown rot (CR), caused by Fusarium species, is the most serious biotic threat to the Australian wheat industry. Compared with common wheat (2n=6x=42), durum wheat (2n=4x=28) is more susceptible to CR. In an effort to understand the genetics of CR resistance in durum wheat, we have analysed three sets of Langdon-Triticum dicoccoides (LDN-DIC) disomic chromosome substitution lines. We found significantly different levels of CR resistance among these substitution lines. CR resistance ascribable to particular LDN chromosome differed for the 3 substitution sets, indicating that genes conferring CR resistance in the three donor parents have different chromosomal locations. With better CR resistance than either parent, LDN (PI481521-2A) was the least susceptible genotype among the substitution series it came from. These data suggest that the 2A chromosome of LDN might harbour genes that increase CR severity/susceptibility, thus replacing it with a homologue from another genotype may be beneficial in improving CR resistance. On the contrary, the two available 3B substitutions [LDN(IsraelA-3B) and LDN(PI478742-3B)] had the lowest CR resistance among their respective sets of substitutions series, suggesting that the LDN 3B chromosome may be more important in reducing CR infection than other chromosomes. Thus retaining LDN 3B could be beneficial in generating CR-resistant durum wheat. Further studies are required to determine if these chromosomes have similar effects in different durum genetic backgrounds.