Leonova I.N.,RAS Institute of Cytology and Genetics |
Budashkina E.B.,RAS Institute of Cytology and Genetics |
Flath K.,Federal Research Center for Cultivated Plants Julius Kuehn Institute |
Weidner A.,Leibniz Institute of Plant Genetics and Crop Plant Research |
And 2 more authors.
Cereal Research Communications
A leaf rust resistance gene transferred from the tetraploid wheat Triticum timopheevii (Zhuk.) Zhuk. (genomic composition: A t A t GG) into common wheat Triticum aestivum L. conditioned resistance at the seedling and adult plant stages in the introgression line 'line 842-2'. To determine chromosome location and to map the resistance gene an F 2 population from a cross between 'line 842-2' and susceptible wheat cultivar 'Skala' was developed and screened against leaf rust pathotype 77 ( Puccinia triticina Erikss.). Microsatellite markers detected introgressions of the T. timopheevii genome on chromosomes 1A, 2A, 2B, 5B and 6B of 'line 842-2'. Linkage analysis revealed an association between leaf rust resistance and microsatellite markers located on chromosome 5B. The markers Xgwm880 and Xgwm1257 were closely linked to the resistance gene with genetic distances of 7.7 cM and 10.4 cM, respectively. Infection type tests with three leaf rust isolates resulted in different patterns of infection types of 'line 842-2' and 'Thatcher' near-isogenic line with the Lr18 gene on chromosome 5B. The data corroborated the hypothesis of the diversity of the resistance coming from T. timopheevii . The resistance gene of the introgression 'line 842-2' seems to be different than Lr18 and therefore it was designated LrTt2 . © 2010 Akadémiai Kiadó. Source
Milcevicova R.,ARC Seibersdorf Research |
Gosch C.,Vienna University of Technology |
Halbwirth H.,Vienna University of Technology |
Stich K.,Vienna University of Technology |
And 12 more authors.
The bacteria Erwinia amylovora, the causal agent of fire blight, infects most members of the Maloideae including pear and apple. In this work the defense responses against this pathogen were monitored in two apple species grown in vitro, in the susceptible Malus domestica Borkh. cv. 'Idared' (later on 'Idared') and the resistant Malus x robusta (Carrière) Rehder var. persicifolia Rehder (Mrp). Our results indicate that the resistant plants might represent a less favorable environment for bacterial growth. At the same time, in these plants higher basic levels for some defense-related compounds such as salicylic acid or their activities such as the PAL enzyme activity can be found. In fire blight infected plants both the known pathways for SA synthesis as well as most of the phenylpropanoid genes examined were repressed due to disease, but apparently could be compensated by complex regulatory mechanisms. Not only the nature but also the quantity of defense-related compounds is likely to influence the outcome of plant-pathogen interactions. © 2010 Elsevier Ireland Ltd. Source