Source: CropBiotech Update

Wheat plants can be destroyed by the soil nematode Heterodera avenae without protection by the Cre genes. Cre-3, in particular, has been incorporated into several wheat varieties lacking nematode resistance; these transgenic plants have already been distributed to breeders.

Identifying wheat carrying the Cre-3 gene is undertaken by marker-assisted selection (MAS), using Cre3spf/2. The process, however, cannot distinguish between plants homozygous for Cre-3 and those heterozygous for it. MAS, moreover, is costly.

E.M. Martin and colleagues of Primary Industries Research in Victoria Australia, however, recently reported the “Identification of microsatellite markers associated with the cereal cyst nematode resistance gene Cre-3 in wheat.” Their findings are published in the Australian Journal of Agricultural Research.

By mapping genes closest to Cre-3, Martin’s research team found a microsatellite marker, designated as Xgwn301. Tests have shown that the association between marker and gene is maintained through different stages of introgression, and is not influenced by the presence of other Cre genes. This is important when considering the incorporation of more than one resistance gene into adapted wheat varieties, and, since Xgwn301 is specific for Cre-3, the marker may help overcome the challenge of pyramiding Cre genes.

Download the article at http://www.publish.csiro.au/journals/ajar