Wild Emmer Accession Research Articles

Chromosomal location of a Triticum dicoccoides-derived powdery mildew resistance gene in common wheat by using microsatellite markers.

The powdery mildew resistance has been transferred from an Israeli wild emmer (Triticum dicoccoides) accession "G-305-M" into common wheat by crossing and backcrossing (G-305-M/781//Jing 411*3). Genetic analysis showed that the resistance was controlled by a single dominant gene at the seedling stage. Among the 102 pairs of SSR primers tested, four polymorphic microsatellite markers (Xpsp3029, Xpsp3071, Xpsp3152 and Xgwm570) from the long arm of chromosome 6A were mapped in a BC(2)F(3) population segregating for powdery mildew resistance and consisting of 167 plants. The genetic distances between the resistance gene and these four markers were: 0.6 cM to Xpsp3029, 3.1 cM to Xpsp3071, 11.2 cM to Xpsp3152 and 20.4 cM to Xgwm570, respectively. The order of these microsatellite loci agreed well with the established microsatellite map of chromosome arm 6AL. We concluded that the resistance gene was located on the long arm of chromosome 6AL. Based on the origin and chromosomal location of the gene, it is suggested that the resistance gene derived from "G-305-M" is a novel powdery mildew resistance gene and is temporarily designated MlG.

Resistance to powdery mildew in wild emmer (Triticum dicoccoides Körn.)

Wild emmer from 73 collection sites, including 107 accessions from Israel, two from Lebanon and one from Turkey, were evaluated for resistance to powdery mildew in field nurseries in Israel and the Netherlands. The wild emmer entries displayed a diversity of responses to powdery mildew infection, ranging from high resistance to complete susceptibility. Most entries were resistant in at least one of the nurseries; several entries proved to be resistant in all the tests. Comparing the reactions of 47 wild emmer accessions tested in six nurseries, 11 markedly different patterns were discerned, indicating the probable presence of several different resistance genes. Genes for resistance to powdery mildew appear to be very common in wild emmer indigenous to Israel. Resistance was found in accessions from most collection sites, in all the geographic regions represented in the collection. The common occurrence of resistance and the apparent diversity of genotypes makes wild emmer a rich gene-pool for resistance to powdery mildew. Since genes for resistance to wheat pathogens can be quite readily transferred to cultivated wheat, wild emmer may be utilized as a valuable source of powdery mildew resistance in wheat breeding.

A valuable source of yellow rust resistance in Israeli populations of wild emmer,Triticum dicoccoides Koern.

An extensive collection of wild emmer was screened for yellow rust resistance in a joint project by research institutes in Israel and The Netherlands. In inoculation experiments performed both in seedling stage and at maturity, the wild emmer accessions displayed a diversity of responses to yellow rust infection, ranging from immunity to complete susceptibility.