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Fluorescence and genomic in situ hybridization (FISH and GISH) were used to establish the cytogenetic constitution of two wheat × Thinopyrum intermedium partial amphiploids H95 and 55(1-57). Both partial amphiploids are high-protein lines having resistance to leaf rust, yellow rust and powdery mildew and have in total 56 chromosomes per cell. Repetitive DNA probes (pTa71, Afa family and pSc119.2) were used to identify the individual wheat chromosomes and to reveal the distribution of these probes within the alien chromosomes. FISH detected 6B tetrasomy in H95 and a null (1D)-tetrasomy (1B) in 55(1-57). GISH was carried out using biotin labeled Th. intermedium DNA and digoxigenin labeled Pseudoroegneria spicata DNA as probes, subsequently. GISH results revealed 44 wheat chromosomes and four Thinopyrum chromosome pairs, including three S and one J chromosome pairs in line H95. Line 55(1-57), contained 42 wheat chromosomes and six Th. intermedium pairs, including two S and one JS pairs. Additionally, two identical translocated chromosome pairs with diminished affinity to the alien chromatin were detected in both amphiploids. Another two translocations were found in 55(1-57), with satellite sections from the Thinopyrum J genome.
Background. The pumpkinseed, Lepomis gibbosus (L.), is one of 23 introduced fish species in Bulgarian freshwaters. With this study we attempt to contribute to clarifying the factors that effect pumpkinseed abundance and demographic structure in water bodies differing in macro- and microhabitat parameters. Materials and Methods. Fish were collected during the breeding period of pumpkinseed (May–June 2010) by minnow traps arranged in 31 sites in the littoral zone of 13 fresh water bodies (former- and active sand-pit lakes, reservoirs, adaptive ponds of refineries). Demographic structure (length and age) and abundance (Catch Per Unit Effort; CPUEN; fish per trap per hour) of pumpkinseeds from different sites were compared to provide information about ecological requirements of this species. Results. L. gibbosus dominated at 24 sites and comprised 86.7% of all fish caught. The mean pumpkinseed abundance was 6.35 ± 7.2 fish per trap per hour (mean ± SD). Pumpkinseeds were most numerous in the littoral zones of the former sand-pit lakes, where pumpkinseed’s CPUEN achieved values of 20 fish per trap per hour. Water body use had a significant effect on pumpkinseed abundance and the statistical analyses revealed that the littoral zones in the active sand-pit lakes were characterized by the lowest number of pumpkinseeds than the other types. Microhabitat parameters such as silt and sand bottom substrate also significantly affected pumpkinseeds abundance, size, and age, while gravel significantly affected body length but not abundance and age. Aquatic vegetation also had a significant impact on the abundance and at sites with dense vegetation pumpkinseeds were more abundant than at the sites with sparse vegetation. At the sites where piscivore fish occurred, the mean length and mean age of pumpkinseed were lower. Conclusion. Human activities facilitate establishment of the pumpkinseed population, mainly by extending suitable breeding places for pumpkinseed and eliminating its natural competitors and predators. Some parameters as sand or silt bottoms in littoral area and dense submerged vegetation may use as indicator of suitable conditions for pumpkinseed.
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