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Phytoplankton diversity and their relationship with water quality parameters in the middle basin of Ogun River, Abeokuta, Southwest Nigeria
5-13Views:5Phytoplankton are crucial bioindicators for assessing freshwater ecosystem health. This study investigates the diversity and distribution of phytoplankton and key water quality parameters in the Ogun River. Monthly samples were collected from three sites along the river between February and August 2024. Phytoplankton samples were preserved with 4% formalin and analyzed microscopically, while water quality parameters, including temperature, pH, dissolved oxygen, conductivity, transparency, total dissolved solids, nitrate, phosphate, alkalinity, and hardness, were measured using standard methods. Results showed temperature ranged from 27.3–31.9 °C, pH from 6.7–9.4, dissolved oxygen from 4.3–7.2 mgL-1, conductivity from 10.8–20.9 µS/cm, transparency from 0.27–1 m, and other parameters within specified ranges. Sixteen phytoplankton species from 10 families were identified, with the Bacillariophyceae family being the most dominant, representing 7 species. Lyngbya spp. was the most abundant species, followed by Pediastrum simplex. Species richness was 12 species at Site A, 13 at Site B, and 14 at Site C. Dominance values were 0.13, 0.11, and 0.12, respectively. Simpson’s diversity index ranged from 0.87 to 0.89, and the Shannon-Weiner index was 2.24 at Site A, 2.38 at Site B, and 2.35 at Site C. One-way ANOVA tests showed no statistically significant differences in diversity indices among the three sampling sites (p > 0.05), indicating relatively consistent phytoplankton diversity across the study area. These findings highlight the importance of integrated biological and physicochemical monitoring for effective water management and ecosystem conservation in the Ogun River.
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The system of faunacomponents conception and its application to qualify the degree of naturalness of fish assemblages
93-101Views:150The increase of species richness in communities of natural biogeographic regions in an anthropogenic way can be expressed as biogeographic pollution. Where there is contaminated fauna, one must investigate how this occured. I studied how the members of Hungarian fishfauna could be present resident and have managed to workout a so-called system of fauna component conception which is suitable for this requirement.
The expression of ’faunacomponent’ includes other expressions. That kind of species belong to a certain faunacomponent that reached the studied area in the same way. Species reached the studied area without an anthropogenious contribution are qualified as native fauna components. These kind of species are endemic species, occasional species and settlers. In contrast to native faunacomponents, some kind of human influence is always detectable in connection with the way reached the studied area by non-native species. Accordingly, group of non-native species includes directly or indirectly facilitated settlers, species that are introduced accidentally and those introduced intentionally. It is obvious that classifying a given species could be construed solely in connection with a certain area.
Applying Shannon diversity index I have initiated the assemblage natural index (ANI) in order to show a way how to use the system of faunacomponent conception in practice. ANI refers to the degree of naturalness of faunistical samples. If ANI > 1 it means there are not any non-native species and ANI < 1 it means there are some non-native species in the sample respectively. In the latter case ANI decreases proportionally with the number of non-native species and specimens. In that special case when only one specimen of only one non-native species can be found in the faunistical sample ANI = 1. -
Investigation of genetic diversity in irradiated maize lines and its relation to hybrid performance
20-26Views:564Knowledge of genetic diversity among available parental lines is fundamental for successful hybrid maize breeding. The aims of this study were to estimate (1) genetic similarity (GS) and genetic distance (GD) (based on Jaccard index) in four maize inbreed lines; (2) to classify the lines according to their GD and GS; (3) to determine hybrid performance based on GD and heterosis for yield ability in 4x4 full diallel system. We used morphological description and AFLP (amplified fragment length polymorphisms) for estimation genetic polymorphism in four maize inbred lines. We estimated the applicability of genetic similarity in SC and reciproc hybrids for prediction of their performance.
Three primer combinations were used to obtain AFLP markers, producing 207 bands, 70 of whit were polimorphic. The dendogram based on genetic similarities (GS) and genetic distance (GD) and morphological description separated four inbred lines into well-defined groups. Morphological description just with AFLP analysis showed reliable results. In view of genetic distance, the UDL 1 line and their linear and reciprocal crosses showed significant heterosis effect, which was confirmed by heterosis calculation based on grain yield. -
Results of fast neutron induced mutations in M1 and M2 generations of sorghum (Sorghum bicolour)
49-54Views:210Due to climatic barriers, the genetic variability of Sorghum varieties decreases away from the gene centre, therefore hybrids cultivated in Hungary are restricted to a relatively limited genetic basis. This limited genetic basis results in a lower rate of genetic improvement, so the genetic basis of cytoplasm factors are to be extended. We enhanced the diversity of primary materials by fast neutron treatment. As a result of this treatment we detected sterile, deformed specimens with double panicles in the stock treated with a dose of 12.5 Gy in the M1 generation. Agronomically useful
specimens were found in the stock treated with 10 Gy and 7.5 Gy doses, where the leaf area index (LAI) and Harvest- index gave higher values than those of the control group. In the stock treated with 5 Gy dose, variations were less significant. In the reseeded M2 generation we detected albino specimens with extreme chlorophyll defects in the 10 Gy Zádor stock. -
Morpometric study of Hungarian honey bee (Apis mellifera L.) colonies
59-63Views:1625The honey bees are essential for the pollination of agricultural plants. The Pannonian honey bee, Apis mellifera pannonica, is native to Hungary, only these subspecies are being bread in our country. The parameters have been separated the pannon and italian honey bee subspecies, the colour of tergit, the cubital index and proboscis length. The morphometric analisys is of special importance because this, on the one hand, shows correlation with honey bee production and on the other hand, the pure morphometric charactersitics is the basis of any potential honey bee export. Mitochondrial DNA and microsatellites are the common methods to define genetic diversity and the separation of subspecies.