Submitted to: International Wheat Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 15, 2008
Publication Date: August 24, 2008
Citation: Klindworth, D.L., and Xu S.S. 2008. Development of a set of stem rust susceptible D-genome disomic substitutions based on rusty durum. In: R. Appels, R. Eastwood, E. Lagudah, P. Langridge, M. Mackay, L. McIntye, and P. Sharp (Eds.) Proc. 11th Int. Wheat Genet. Symp., vol. 2. Sydney University Press, Sydney, Australia. Pp 367-369.
Stem rust (Puccinia graminis Pers.:Pers. f.sp. tritici Eriks. and Henn.) is one of the most devastating diseases of wheat (Triticum aestivum L.) and durum (T. turgidum L. ssp. durum). Prior to the development of molecular techniques, studies of genes for stem rust resistance genes in wheat were completed using the Chinese Spring (CS) aneuploids. However, few genes were studied in durum because the major set of durum aneuploids, Langdon D-genome disomic substitutions (LDN-DS), had limited use due to the presence of at least three genes for stem rust resistance. Thus, development of a set of stem rust susceptible durum D-genome disomic substitutions would be useful for studies of stem rust resistance in tetraploid wheat. To do this, a breeding process was initiated where the LDN-DS were backcrossed to stem rust susceptible durum line 47-1. In the BC1 generation, double monosomic plants that were susceptible to three stem rust pathotypes were selected for backcrossing. The stem rust susceptible genotype ‘Rusty’ became available during this breeding process and backcrossing to 47-1 was discontinued in favour of Rusty. In each cycle, double monosomic plants were selected for backcrossing. After six backcrosses to Rusty were completed for all 14 chromosomes, double monosomic plants were selfed and disomic substitutions were selected and confirmed using molecular markers, endosperm protein markers, and conventional cytogenetic techniques. Twelve Rusty-DS lines have thus far been selected, the exceptions being 5D(5B) and 6D(6B) DS, which are presently under selection.