Implementation of markers in Australian wheat breeding

Abstract

Genetic associations of morphological, biochemical, and DNA markers with economically important traits can be used for indirect selection of the traits. Chromosomal linkage between pseudo-black chaff and the stemrust resistance gene Sr2, and between the red glume gene (Rg1) and the stripe rust resistance gene Yr10, have been used in this way for many years. Similarly, linkages between disease resistance genes, such as Sr38,Lr37, and Yr17, have been used to achieve resistance to multiple diseases while selection is performed for resistance to one disease. Alleles at the Glu loci, assessed as protein differences, have been used as predictors of dough strength. More recently, DNA markers have been developed and used, especially to select for resistance to cereal cyst nematode, a trait which is difficult and expensive to assess with conventional bioassays. We found that the major use of DNA markers was for selection for traits of substantial economic importance, which were primarily determined by a single gene, and where the non-marker assay was expensive and unreliable. The other uses of markers were for pyramiding several genes influencing one trait, or for rapid backcrossing.

Characterisation and marker development for low molecular weight glutenin genes from Glu-A3 alleles of bread wheat (Triticum aestivum. L)

“…Gleanlea (GluA3g), Cloutier et al (2001) have reported positive effects for the Glu-A3 locus on dough strength. In Australia, specific LMW-GS alleles have been actively selected against is certain breeding programs, for example Glu-B3e (Lawrence 1986) and GluA3e (Eagles et al 2001).…”

Marker-assisted selection: an approach for precision plant breeding in the twenty-first century

“…Classical examples of traits that are difficult and laborious to measure are cereal cyst nematode and root lesion nematode resistance in wheat (Eastwood et al 1991;Eagles et al 2001;Zwart et al 2004 These advantages can be exploited by breeders to accelerate the breeding process (Ribaut & Hoisington 1998;Morris et al 2003). Target genotypes can be more effectively selected, which may enable certain traits to be 'fast-tracked', resulting in quicker line development and variety release.…”

Development of a diagnostic co-dominant marker for stem rust resistance gene Sr47 introgressed from Aegilops speltoides into durum wheat

“…), and root lesion nematode (Pratylenchus spp.) resistance in wheat are examples of traits that are difficult to evaluate (Buerstmayr et al 2009;Miedaner and Korzun 2012;Eastwood et al 1991;Eagles et al 2001;Zwart et al 2004). Secondly, MAS allows for pyramiding of multiple genes by screening multiple markers on individual plants of a population, thereby greatly expediting the production of breeding lines.…”