Mapping of resistance genes to brown rust in 1R chromosome of rye (Secale cereale L.)

Five resistance genes to single-pustule isolates Nos. 12, 81,108 and 7 of brown rust were mapped on 1R chromosome of rye using two different F₂ populations. Under segregation analysis it was found linkage between genes controlling resistance to single-pustule isolates No. 12, 81, 108 and 25 and isozyme locus Prx7, which to be localized on chromosome 1R. The recombination frequencies are 0.32, 0.28, 0.29 and 0.32 correspondingly. Also we were found linkage between Prx7 and gene, controlling resistance to single-pustule isolate No. 7. Recombination frequency in this case was equal 0.10 and 0.29 in dependence on analyzing hybrids.

Absence of an acid phosphatase isozyme locus as a marker candidate for true to typeness in woodland grape (Vitis vinifera L. ssp. sylvestris Gmelin)

<p style="text-align: justify;">The quest and conservation of existing populations of woodland grape (<em>Vitis vinifera</em> L. ssp. <em>sylvestris</em> Gmelin), the supposed progenitor of the European grapevine (<em>Vitis vinifera</em> L. ssp. <em>sativa</em>) and a significant actor in the evolution of grapevine, has great importance in preserving biodiversity. The proof of true-to-typeness is highly important in ex-situ conservation, because the contamination risk of the woodland grape populations is very high. Some characteristic “<em>sylvestris</em>” simple sequence repeats (SSR) alleles were identified, but they are only characteristic in a specific population.</p><p style="text-align: justify;">In our recent study, the SSR profiles of 32 woodland grapes were compared to those of 16 European grapevine varieties and 20 rootstocks. Morphology and SSR analyses suggested that the analysed <em>Vitis vinifera</em> ssp. <em>sylvestris</em> Gmelin accessions were true-to-type. In this report, the results of the acid phosphatase isoenzyme analyses of the same woodland grape accessions are presented and a new marker for true-to-typeness is suggested.</p>

Isozyme Locus Pgm-1 Is Tightly Linked to a Gene (Vf) for Scab Resistance in Apple

Pgm-1, the gene responsible for variation in the most anodal isozyme of phosphoglucomutase in apple (Malus spp.), is shown to lie ≈8 centiMorgans from the gene Vf, which confers apple-scab resistance. The proximity of the marker and the ease by which allozymic forms can be resolved suggest that Pgm-1 will be useful for following the inheritance of scab resistance conferred by Vf.