embryological and anatomical analyzes were conducted to meet the objective. The morphological characteristics and DNA dendrogram revealed that G. gracilis and G. elwesii were situated in the same cluster and had significant morphological similarity, whereas plants from populations identified as G. nivalis were dissimilar in morphology and situated in a separate cluster. The revealed features of the generative sphere showed similarities across the species. Scanning electron microscopy (SEM) analyses of the surface revealed that the anticillinal walls of G. elwesii and G. gracilis were straight, while those of G. nivalis were wavy. This research demonstrated that the plants of G. elwesii and those from populations identified as G. gracilis are morphologically, embryologically and genetically similar, thus refuting the hypothesis. This study did not provide sufficient evidence to support the claim of the existence of G. gracilis in the Bulgarian flora; the populations identified as G. gracilis in Bulgaria may be forms of G. elwesii.

The effect of the soil herbicide isoxaflutole on the growth and development of new corn hybrids in controlled conditions was studied. Conducted assays confirmed that tested hybrids exhibit different sensitivity to herbicide treatment, expressed as a decrease of chlorophyll or increase of anthocyanin content. The lowest content of chlorophylls was determined for hybrid P0216 and the highest anthocyanin levels were observed for hybrid P9241. Present investigation was performed for evaluation the toxic effect of the herbicide and demonstrated that plant pigment content can be used as a marker for abiotic stress. This study could be very useful for practical applications as a preliminary test for phytotoxicity and/or sensitivity of different crops or model plants to herbicides.

The fruits of the Capsicum genus plants are valued for their spicy taste, unique only to them, due to the capsaicin alkaloid and its analogs, named capsaicinoids. Capsaicinoids are absent in sweet peppers, which are sometimes preferred due to the lack of pungency. Their presence or absence is a genetically controlled process, and many of the genes that affect capsaicin synthesis are known. The Pun1 gene plays a lead, and mutations in this locus are the most common cause of loss of pungency in the three related species Capsicum annuum, Capsicum chinense, and Capsicum frutescens. In the present study, we analyzed the effect of the Pun1 gene on the synthesis of capsaicin in hybrid lines of the genus Capsicum. This analysis was performed by comparing the fruit spiciness profile (determined organoleptically) and the allelic state of the Pun1 gene (determined by PCR reaction, using allele-specific primers). The comparative analysis confirms our hypothesis that the pungent and lack of pungent in the selected hybrid lines is entirely controlled by the action of this Pun1 gene only.

Expression of Bacillus thuringiensis delta-endotoxins has proven to be a successful strategy for obtaining insect resistance in transgenic plants. Drawbacks of expression of a single resistance gene are the limited target spectrum and the potential for rapid adaptation of the pest. Hybrid toxins with a wider target spectrum in combination with existing toxins may be used as tool to mitigate these problems. In this study Red Star potato plants were genetically modified to resist insect attack by Colorado potato beetle, through insertion of synthetic version of such a hybrid gene, SN19. This makes it a useful tool for resistance management strategies.

The information about the authenticity of newly or already established animal cell cultures is essential. By using DNA analysis six cell lines has been investigated: ЗТЗ, HeLa, McCoy, the last four was made cytogenetic analysis confirmed that serum-free cell strains McCoy-Plovdiv and HЕp-2-Plovdiv E are originally derived from McCoy and HЕp-2 cell lines. PCR -analysis demonstrated that 3T3 cells are mouse originally, HeLa, HЕp-2 and HЕp-2-Plovdiv E are with the human origin and McCoy and McCoy-Plovdiv are hybrid cells carrying mouse and human genes in their genome.