The application of high-density genetic maps of rye for the detection of QTLs controlling morphological traits

The development of genetic maps is, nowadays, one of the most intensive research activities of plant geneticists. One of the major goals of genome mapping is the localisation of quantitative trait loci (QTLs). This study was aimed at the identification of QTLs controlling morphological traits of rye and comparison of their localisation on genetic maps constructed with the use of genetically different germplasms. For QTL analyses, two high-density consensus maps of two populations (RIL-S and RIL-M) of recombinant inbred lines (RIL) were applied. Plant height (Ph), length of spikes (Sl) and the number of spikelets per spike (Sps) were studied in both populations. Additionally, the number of kernels per spike under isolation (Kps), the weight of kernels per spike (Kw) and thousand kernel weight (Tkw) were assessed in the RIL-M population. Except for Tkw, the majority of the traits were correlated to each other. The non-parametric Kruskal–Wallis (K-W) test and composite interval mapping (CIM) revealed 18/48 and 24/18 regions of rye chromosomes engaged in the determination of Ph, Sl and Sps in the RIL-S and RIL-M populations, respectively. An additional 18/15 QTLs controlling Kps, Kw and Tkw were detected on a map of the RIL-M population. A numerous group of QTLs detected via CIM remained in agreement with the genomic regions found when the K-W test was applied. Frequently, the intervals indicated by CIM were narrower.     

Genetically directed differential subtraction chain products related to in vitro response of immature embryos of rye (<Emphasis Type="Italic">Secale cereale</Emphasis> L.): isolation,characterization, and expression analysis

Winter rye (Secale cereale L.) is known to be recalcitrant to tissue culture response (TCR). Moreover, the mechanisms controlling TCR are poorly recognized. In the present study, a Genetically Directed Differential Subtraction Chain (GDDSC) strategy was used to isolate genomic regions associated with TCR. Two pairs of bulks, R-NR and E > 90–E < 25, were prepared, and for each pair, the bulk was used both as a tester and as a driver. After eight rounds of subtraction, 45 unique GDDSC products were obtained. To verify the connection between GDDSCs and TCR two approaches were applied: Real-Time RT-PCR analysis and genetic mapping. The expression profiles of four out of six investigated products agrees with the phenotype and subtraction direction. Two from the developed GDDSC-SCAR markers showed polymorphism in lines L9 and L318, the parental components of a mapping population. The polymorphic SCAR GDDSC markers were mapped on the rye chromosome 4R (SCAR-GDDSC NR 440BamHI) and 6R (SCAR-GDDSC E < 25 340BamHI). The marker E < 25_340B9 was localized in the border region of QTL for embryogenic callus production.     

In vitro evaluation of photodynamic activity of methylene blue against Trichophyton verrucosum azole-susceptible and -resistant strains

The intense search for the “Holy Grail” of antifungal therapy can be observed today. The searches are not limited only to discovery of potential antifungal drugs, but also new therapeutic strategies involving the use of chemosensitizers to achieve synergistic effect or physicochemical factors inducing stress conditions in fungal cells. In this study was examined in vitro effectiveness of photodynamic antifungal strategy with methylene blue using a light beam with a wavelength equal to 635 nm toward the Trichophyton verrucosum susceptible and itraconazole- and/or fluconazole-resistant strains. Methylene blue used at concentration equal to 5 μg/mL and in the presence of 40 J/cm² of light energy showed fungicidal effect toward the susceptible strains. However, for azole-resistant isolates, only the energy dose equal to 60 J/cm² at 5 μg/mL of methylene blue allowed to kill the pathogen. This study confirms that methylene blue induced by red light has a definite inhibitory effect on zoophilic dermatophytes.