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- Rules of symbolization of genes and markers >>>
- List of symbols and descriptions of genes and markers >>>
- Chromosomal and/or regional localization of genes and markers >>>
- Physical map of chromosomes and chromosome arms >>>
- Orders genes and marker on chromosomes, chromosome arms, and segments >>>
- List of genetic linkage values between genes/markers >>>
- Karyogram and homoeologous genome synteny >>>
- Chloroplast genes >>>
- Mitochondrial genes >>>
- Transposons >>>
- Rye-specific DNA sequences >>>
- B chromsomes >>>
- Resistance genes >>>
- QTLs >>>
- Notes >>>
- References >>>
Rye is a cereal,
which played a major role in the feeding of European populations owing to its considerable winter hardiness. Recently the world production amounts about 30 million tons (Mt). Rye (Secale cereale L.), a secondary crop, is cultivated since more than 5,000 years. It is still grown on more 9 Mio hectares worldwide. About 94 % of the world production is harvested in Russia (37 % of the total acreage), Belarus (9 % of the total acreage), Poland (22 % of the total acreage), and Germany (9 % of the total acreage). Original rye was a meter-high grass. Meanwhile rye became a modern crop plant with all the technological and agronomic advantages. There is a subsequent increase in rye grain yield caused by improvement of agronomy and new (hybrid) varieties.
Quite early rye became a subject of cytological research. The large chromosomes and the diploid genome
made rye suitable for several microscopic studies. However, the allogamous flowering and the genetic heterozygosity aggravated genetic analysis. Despite of first approaches utilizing trisomics and
reciprocal translocations, the breakthrough of rye genetics was associated with latest molecular techniques. Recently there are more than 2,050 biochemical, molecular, and morphological markers
available, as compared to about 720 during the update in 1998 (Schlegel et al. 1998, 384). From this number about 80 % are molecular
markers gathered during the last decade, 12 % biochemical markers, and about 8 % mapped morphological features, respectively. Best investigated is chromosome 1R, followed by chromosome 6R, 5R, 2R,
4R, 7R, and 3R, respectively. Suitable markers exist for important resistance and fertility traits applied in hybrid breeding. Even first QTLs were mapped on several rye chromosomes.
Genetic studies were always promoted by the dual role of rye – as an independent crop plant and
as an important donor species for wheat improvement (Schlegel 2006, 398). The first man-made crop plant, triticale, carries the diploid genome of
rye. Some of the most successful wheat varieties of the world possess rye genes of chromosome 1R. Since 1973, in more than 250 cultivars of wheat showing this particular type of translocation
were described.
However, the diversity of interests in studies on rye causes a different use of genetic concepts. This
concerns not only the designation of genes and markers but also the system of investigations, the presentation of data, and the interpretation of the results. Although during the last decade
progress was achieved, there are still many problems with the uniform naming of morphological, cytological, or biochemical traits and markers as well as the interpretation of the findings. Hence,
some compromises are unavoidable if all available genetic results are included into a compilation of data. Therefore, some rules of symbolization of genes and markers are given below based on similar
approaches in other plants. Contradictory designations were either standardized, renamed or provided with suitable explanations.
Because the mapping data, linkage results, and the order of markers along the chromosomes sometimes
strongly deviate between the authors and their own experiments, the data have to be shown separately. A re-examination of such results is not practicable.
Further data on rye cytogenetics and breeding can be obtained via http://www.plant-breeding.privat.t-online.de
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