GENES FOR POWDERY MILDEW REACTION During the past six years an annually updated list of genes (alleles) for powdery mildew reaction in barley has been published. The following changes and additions should be made to the list published in BGN 18:120-134, 1987. Two new alleles in the M1-a locus, M1-a20 and M1-a21 derived from Hordeum spontaneum, are described by Jahoor and Fischbeck (1987). They also published further details on genes M1-a16 through M1-a19 and M1-i, also originating from H. spontaneum. An apparently new gene tentatively designated M1-(Ga) in the Australian commercial variety 'Galleon' is described by Hossain and Sparrow (1986). Gene M1-(Ga) is loosely linked to locus Hor1 on chromosome 5 (rec. pet. 35.7), is not in locus M1-a, and is apparently different from resistance genes in other powdery mildew response loci on chromosome 5.

LOCI FOR DISEASE AND PEST REACTION

The following list of gene loci affecting disease and pest reaction in barley is compiled based on the comprehensive list of gene loci in barley published by Søgaard and Wettstein-Knowles (1987).

A new gene for barley stripe mosaic virus response, proposed designated rsm and located on barley chromosome 1, was de- scribed by Timian and Franckowiak (1987).

REFERENCES

Hossain, A. and D.H.B. Sparrow (1986) Powdery mildew (Erysiphe graminis f.sp. hordei) on barley. Pathogen variability and host resistance. In: Biennial Rep. 1984-1985, Waite Agric. Res. Inst., Univ. Adelaide, South Australia, pp. 64-65.

Jahoor, A. and G. Fischbeck (1987) Genetical studies of resistance of powdery mildew in barley lines derived from Hordeum spontaneum collected from Israel. Plant Breeding 99, 265-273.

Søgaard, B. and P. von Wettstein-Knowles (1987) Barley: Genes and chromosomes. Carlsberg Res. Comm. 52, 123-196.

Timian, R.G. and J.D. Franckowiak (1987) Location of a factor for barley stripe mosaic virus reaction on chromosome 1 Barley Genet. Newsl. 17, 79-82.