Abstract
There are many naturally occurring variants at the Ml-a locus in barley that confer resistance to the powdery mildew fungus Erysiphe graminis f. sp. hordei. Since the Ml-a locus is bracketed by Hor-1 and Hor-2, genes that encode storage proteins in the endosperm, the Ml-a locus is amenable to fine structure analysis. Rare susceptible recombinants, as judged by exchange of flanking markers, were recovered in F3 families from the Ml-a10 x Ml-a1, Ml-a1 x Ml-a15 and Ml-a6 x Ml-a13 crosses. Some susceptible recombinants were recovered from the Ml-a6 x Ml-a13 cross that did not fit the expected F 3 family segregation ratios. The Ml-a6/Ml-a13 recombinants often reverted to resistance in subsequent generations. No recombinants were recovered in the reciprocal cross, Ml-a13 x Ml-a6. The possibility of a transposable element and a possible linear order of six "alleles" at the Ml-a locus is discussed.
Full Text
The Full Text of this article is available as a PDF (1.5 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Engels W. R., Preston C. R. Formation of chromosome rearrangements by P factors in Drosophila. Genetics. 1984 Aug;107(4):657–678. doi: 10.1093/genetics/107.4.657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Masri S. S., Ellingboe A. H. Primary infection of wheat and barley by Erysiphe graminis. Phytopathology. 1966 Apr;56(4):389–395. [PubMed] [Google Scholar]
- Nelson O. E., Klein A. S. Characterization of an spm-controlled bronze-mutable allele in maize. Genetics. 1984 Apr;106(4):769–779. doi: 10.1093/genetics/106.4.769. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nelson O. E. The WAXY Locus in Maize. II. the Location of the Controlling Element Alleles. Genetics. 1968 Nov;60(3):507–524. doi: 10.1093/genetics/60.3.507. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rubin G. M., Kidwell M. G., Bingham P. M. The molecular basis of P-M hybrid dysgenesis: the nature of induced mutations. Cell. 1982 Jul;29(3):987–994. doi: 10.1016/0092-8674(82)90462-7. [DOI] [PubMed] [Google Scholar]
- Saxena K. M., Hooker A. L. On the structure of a gene for disease resistance in maize. Proc Natl Acad Sci U S A. 1968 Dec;61(4):1300–1305. doi: 10.1073/pnas.61.4.1300. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shepherd K. W., Mayo G. M. Genes conferring specific plant disease resistance. Science. 1972 Jan 28;175(4020):375–380. doi: 10.1126/science.175.4020.375. [DOI] [PubMed] [Google Scholar]