Shannon-Weaver Diversity Index Research Articles

Kawí Tamiruyé: a permanent research forest plot in the Sierra Tarahumara

This study characterizes the dasometric and structural parameters of a permanent research plot in northern Mexico. From a total census, 2165 trees (n) were recorded in an area of 1.4 ha-1 and, through the application of various sampling schemes, dasometric variables, and diversity indices were estimated for comparison with the census of a reference plot. We calculated the following dasometric measurements, Quadratic Mean Diameter (QMD)= 12.16 cm, Crown Area (CA)= 61.6%, Reineke's Stand Density Index (SDI)= 668 individuals, Basal Area (BA)= 25.16 m2, Total Volume (Vol)= 158.83 m3 ha-1, aboveground biomass (AGB= 142.78 Mg ha-1) and Carbon (C= 71.39 Mg ha-1). Ecologically, the species with the highest importance value index (IVI) were P. engelmannii and J. deppeana (50.8% and 35%, respectively). The Simpson's dominance index (δ)= 0.39 and diversity (λ)= 0.61 were low, as was the Shannon-Weaver index of diversity (H'= 1.3), which is in agreement with the Margalef index (DMg= 1.04). The value of Pielou's evenness (J'= 0.53) confirmed low abundance. Equidistant systematic sampling at 40 m was closer to the reference census, presenting lower values in the mean and variance estimators compared to the other sampling methods. The results can be included in management portfolios to improve decision-making. Although further studies on site size, inclusion of additive indices, and operational costs are required.

Exploring Genetic Variation and Trait Correlations in ‘Shiqian Taicha’ Tea Based on Comprehensive Analyses of Morphological and Biochemical Diversity

This study explores the genetic variation and trait correlations within a collection of 52 ‘Shiqian Taicha’ tea germplasms originating from Shiqian County, Guizhou Province, China. The ‘Shiqian Taicha’ landraces exhibit substantial genetic diversity and are characterized by unique morphological and biochemical attributes. The Shannon-Weaver diversity index (H’) values for the morphological traits ranged from 0.37 to 2.06, with an average value of 1.02, which suggests a greater level of genetic diversity than those of other domestic tea germplasms. The biochemical analysis demonstrated considerable variation, with coefficients of variation (CVs) for biochemical components ranging from 3.73 to 54.05% (mean CV: 20.35%). In addition, 25 germplasms had epigallocatechin-3-gallate (EGCG) contents ≥ 10%. The correlation analysis revealed significant associations between morphological traits and biochemical components, with particularly positive correlations between the leaf texture and key biochemical components such as total catechins (TC) and EGCG (p < 0.01). The clustering analysis, which was based on morphological and biochemical profiles, further categorized the tea germplasms into distinct groups. Notably, SWD-G, SLD005, SWXD005, and SWD004 were identified as superior germplasms with comprehensive biochemical qualities and high EGCG contents. These unique resources have potential for the cultivation of specific tea varieties with regional characteristics.

Agro-morphological genetic diversity assessment of Amaranthus genotypes from Ethiopia based on qualitative traits

Amaranths are a promising plant in the family of Amaranthaceae because of their nutritional and functional properties, such as their high antioxidant content and dietary fiber content. However, it's being disregarded for several reasons, such as ignorance, a lack of in-depth research, and the plant's long-term genetic growth in Ethiopia, among other factors. In the current work, we described the genetic diversity of 120 amaranth genotypes using qualitative criteria. The experiment, which was configured with an alpha lattice design and duplicated twice, was run for two seasons in 2020 and 2021. Twenty qualitative descriptors were looked for in the gathered data. Among the 20 qualitative variables that were assessed, the chi-square test result indicated the presence of prevailing phenotypic variation. The results of the agro-morphological characterization also revealed a significant amount of variance. The overall mean of the Shannon diversity indices (H') was 0.61. The indices for germination rate, leaf margin, prominence of leaf veins, and the existence of auxiliary inflorescence varied from 0.12 to 0.99. The estimated diversity indices showed more intra-regional diversity (0.66) than inter-regional diversity (0.34), demonstrating the existence of gene flow between growing regions. Shannon–Weaver Diversity Index, ranged from 0.00 for auxiliary inflorescence to 1.94 for leaf coloration, with an overall mean of 19 characters (95%) that were found to have high diversity (> 0.76) while auxiliary inflorescence was invariant. Except for auxiliary inflorescence, all qualitative features showed a lot of variation. Additionally, Amaranthus hybridus L. subsp. cruentus (L.) Theil recorded the greatest Shannon diversity index (0.47) while Amaranthus spinosus L. recorded the lowest (0.00). The hierarchical clustering grouped all the genotypes into three clusters. The first cluster included the most genotypes (58), followed by the second (47), and the third cluster contained the fewest (15). Principal component analysis showed that the first six principal components with eigenvalues greater than one contributed 72% of the variability among genotypes. The study unequivocally demonstrated that, even when the genotypes were grouped into a small number of clusters, there was still enough divergence within the clusters to demonstrate the genotypes of amaranth to have a high genetic diversity. These results indicate that there is substantial genetic diversity among Ethiopian amaranth genotypes, which should be safeguarded and may be utilized in breeding in the future.

Diversity index of argania spinosa l. Skeels plant formation in the algerian western sahara

The argan (Argania spinosa) is a xerothermophilous tree, endemic in North-West Africa. In Algeria, it is found as wild in the northwest of the Hamada du Drâa of Tindouf (Algerian Western Sahara), where it is characterized by a great floristic diversity. Several indices were calculated in this study to have a better knowledge on the state of biological diversity of the argan tree ecosystem. It is characterized by a floristic richness composed of 123 taxa belonging to 38 families including the dominance of three major floristic families: Asteraceae, Brassicaceae and Amaranthaceae. Biologically, the study area is dominated by therophytic species. This therophytization is marked by a general invasion of annual species. The diversity index of Shannon-Weaver (4.42) associated with that of Pilou's equitability (0.843) are relatively high, which showed that the flora of the argan forest of Tindouf is highly diverse. The disturbance index is high (76%) which reflects a significant degree of disturbance of the plant formation and also a strong anthropozoic influence. Bangladesh J. Bot. 53(3): 447-457, 2024 (September)

Construction and Evaluation of Pepper Core Collection Based on Phenotypic Traits and SSR Markers

To streamline germplasm preservation, enhance resource utilization, and improve breeding efficiency, a core germplasm bank was established using 24 phenotypic traits and DNP markers from 155 pepper resources across various regions. Selection of the optimal core germplasm was based on intra-group retention ratio, overall retention scale, and intra-group stepwise clustering retention. Evaluation of phenotypic trait data for the core germplasm utilized mean, variance, range, and coefficient of variation, with principal component analysis confirming the selection. For molecular evaluation, the core germplasm pre-selection plan was based on SSR clustering, allele retention ratio, and Shannon-Weaver diversity index. This approach resulted in a core germplasm of 41 resources, including 6 var. fasciculatum, 7 var. grossum, 3 var. cerasiorme, 6 var. conoides, and 19 var. longum, representing the maximum phenotypic retention and genetic diversity of the 155 pepper resources. Additionally, a core germplasm of 32 resources was generated based on SSR markers, retaining all 54 polymorphic loci. By integrating phenotypic and molecular core collections, a combined core collection of 57 varieties was developed. This collection achieved a 92.55% phenotype retention ratio and a 100% polymorphism site retention ratio. With a 90% compression ratio, it encapsulates the broad genetic diversity of the original germplasm, serving as a comprehensive resource for further research and breeding applications.

Phenotypic diversity in qualitative and quantitative traits for selection of high yield potential field pea genotypes

Field pea (Pisum sativum L.) needs improvement to increase productivity due to its high price and demand. However, the incidence of powdery mildew (PM) disease limits its production. This study aimed to analyze the diversity of qualitative and quantitative traits against powdery mildew resistance by utilizing cluster and principal component analysis to explore PM resistance high-yield potential field peas. Shannon–Weaver's diversity index (Hʹ) displayed high intra-genotype diversity for quantitative and qualitative aspects. Heterogeneity was identified for resistance against powdery mildew infections. Eighty-five genotypes were divided into five groups using Mohalanobis generalized distance (D2) statistics. The highest inter-cluster D2 value was observed between clusters 2 and 3 (11.89) while the lowest value was found between clusters 3 and 4 (2.06). Most of the genotypes had noticeable differences, so these could be employed in a crossing scheme. Twelve genotypes were extremely resistant, 29 genotypes were resistant, 25 genotypes were moderately resistant, 18 genotypes were fairly susceptible, and 1 genotype was susceptible to powdery mildew disease. Among 29 resistant genotypes, BFP77, BFP74, BFP63, BFP62, BFP43, and BFP80 were high yielders and, could be used directly and/or transferred through hybridization to high-yielding disease-susceptible genotypes. Among the 25 moderately resistant genotypes, BFP78, BFP45, BFP79, and BFP48 were found to be high yielders. In principal component analysis (PCA), the first four PCs with Eigen values > 1 accounted for 88.4% variability for quantitative traits. Clustering sorted genotypes into five groups, where groups 1 to 5 assembled 37, 28, 1, 8, and 11 genotypes, respectively. Genotypes of cluster 4 were identified as high yielders with its attributes. Pearson correlation significantly and positively correlated across all traits except for PM. This variation suggested that there is a mechanism to select promising genotypes for field pea breeding. Considering all features, BFP78, BFP77, BFP74, BFP63, BFP62, BFP45, BFP79, and BFP80 could be preferred as high yielders and PM resistance owing to longer pod lengths, seeds per pod and pods per plant.

ORCHID DIVERSITY (Orchidaceae) IN TWO URBAN SITES IN THE STATE OF VERACRUZ, MEXICO

Knowledge of urban orchids and their phorophytes is essential for conservation and education initiatives in these areas. The objective of this study was to assess the diversity of epiphytic orchids and identify their phorophytes at Postgraduate College Campus Córdoba (CPCC) and Paso Coyol Ecological Park (PEPC) in order to better understand the differences in their composition. The hypothesis was that the diversity of naturally established orchids would be higher in the less urbanized area, while the phorophytes would be mostly introduced trees. Orchids growing on phorophytes of the garden area (12 000 m²) of both sites were quantified from November 2019 to December 2021. The origin (endemic, native, or exotic) of the orchids and their phorophytes were determined. Simpson and Shannon-Weaver diversity indices were applied, and Whittaker curves were developed. A total of 13 419 orchid individuals were recorded, divided into 31 species, with 26 species reported in the CPCC and 17 in the PEPC. The Simpson and Shannon-Weaver indices showed that the diversity of epiphytic orchids was higher in the CPCC (1-D = 0.78) than in the PEPC (1-D = 0.41). In contrast, species dominance was lower in the CPCC (H = 2.6) than in the PEPC (H = 1.16). Whittaker curves showed that Catasetum integerrimum was the most abundant species in the CPPC and Platystele stenostachya in the PEPC. The CPCC had a greater level of diversity. Fifteen species of phorophytes were recorded in the CPCC and 10 in the PEPC, with a predominance of exotic species, while introduced species accounted for 70 % of the phorophytes found.

Influence of the hydrological regime of lake buyo on fish community of three floodplains in the Tai national park (southwestern Côte d’Ivoire)

Floodplains play an important role in the ecological functioning of the areas on which they depend. These plains are also of socio-economic interest to the local population, particularly in terms of fishing activities. The fish fauna of three Lake Buyo floodplains (Néma, Libériakôbro and Gah) was studied in relation to the lake's hydrological regime. The aim of this study was to evaluate the influence of the hydrological seasons of Lake Buyo on the structure of the fauna considered. Sampling of fish community was carried out monthly during an annual cycle using experimental fishing. The structure of the fish community was analyzed by determining taxonomic composition, taxon abundances (Ar) and the Shannon-Weaver diversity (H') and Pielou equitability (E) index. Temporal dynamics of the studied parameters were analyzed according to three hydrological seasons: flood season, high water season and recession season. Results showed that total specific richness of ichthyofauna of the studied plains was 38 species, and the richness observed at the different hydrological seasons varied significantly (p < 0.05). The Cyprinidae family was dominant in the abundances recorded at all seasons (48.34% ≤ Ar ≤ 85.5%). It should be noted that the studied ichthyofauna exhibited relatively low diversity and equitability with reference to diversity index (1.42 ≤ H' ≤ 1.46 and 0.28≤ E ≤ 0.29).

Enhancing Maize Germplasm Selection for Genebanks: A Decision Support System Combining Shannon-Weaver Diversity Index and Machine Learning

Enhancing Maize Germplasm Selection for Genebanks: A Decision Support System Combining Shannon-Weaver Diversity Index and Machine Learning

Symbiont Diversity in Imidacloprid-Resistant and Imidacloprid-Susceptible Populations of Nilaparvata lugens (Hemiptera: Delphacidae)1

Abstract Imidacloprid, a neonicotinoid insecticide, is efficacious against hemipterans, including the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). However, frequent use of this insecticide has resulted in the development of high levels of resistance among brown planthopper populations. Endosymbionts of insects have contributed to host physiology and evolution and play a role in resistance to chemical toxins. In this study, polymerase chain reaction–denaturing gradient gel electrophoresis was used to analyze the bacterial and yeast-like symbiont communities of imidacloprid-resistant and -susceptible brown planthopper populations. The Shannon-Weaver diversity index and the evenness index indicated no differences in the richness and the expression of overall species distribution of the symbiotic communities of resistant and susceptible populations. The similarity coefficients of 0.53 and 0.56 for bacterial and yeast-like symbionts, respectively, indicated the main types of differences among microorganisms in resistant and susceptible populations. Sequence comparison analysis indicated the bacterial species in the susceptible population were members of the Enterobacteriaceae and Moraxellaceae, and those in the resistant population were members of the Enterobacteriaceae, Oxalobacteriaceae, Rhodobacteriaceae, and Sphingomonadaceae. Differences also were found in the composition of yeast-like symbionts of the two populations; Cryptococcus luteolus, Pseudozyma aphidis, and Pseudozyma antarctica were detected in the susceptible population, and Cladosporium perangustum was detected in the resistant population.

The biodiversity and conservation assessment of Bamui beel in Bangladesh: Current status and threats

A year-long research was conducted with a novel purpose for categorizing and documenting the existing fish diversity and abundance of Bamui beel in Jamalpur district located in Northeast part of Bangladesh, within a time frame from July 2022 to June 2023. A total of 46 fish species were identified that belonged to 18 taxonomical families and 8 orders. The most abundant family was Cyprinidae (25%). Among 46 species, 37% were commonly available (CA) and 11% were abundantly available (AA) in terms of biodiversity status. According to the global conservational status, around 74% were reported as least concerned (LC) whereas 4% were nearly threatened (NT). On the other hand, in consonance with the conservational status of Bangladesh 52% were least concerned (LC) and 11% were endangered (EN). Pielou’s evenness score in Bamui beel was the highest (0.247) in pre-monsoon and the lowest (0.213) in monsoon. Shannon-Weaver diversity index was ranged from 1.992 to 2.114, whereas Simpson’s dominance index value was a maximum of 0.883 in pre-monsoon and a minimum of 0.852 in monsoon. The yearly fish production of the beel was 7.023 metric tons during experimental year. Besides this, small indigenous species (SIS) of fish dominated with 63.34% of the beel's species makeup. Nevertheless, the abundance and diversity of fish species are diminishing daily in this beel. For preserving the fish diversity of Bamui beel calls for the implementation of effective fishery management practices, vigilant monitoring to prevent overfishing, and a strong emphasis on raising awareness among fishermen.

Macrobenthic fauna and the ecological status of a shellfish farm in the Mediterranean Sea (Algeria)

A faunistic and ecological study on the benthic macrofauna was carried out in the shellfish farm in Ain Chorb (Ain Taya), central Algeria. This study aims to characterise the composition, structure, and functioning of the benthic community to establish the reference state and ecological quality of the shellfish farm and to monitor its evolution through an adapted sampling and observation methodology adapted and used by the scientific community at the international level. Benthic fauna samples were collected in two different periods (warm and cold season) between February 2020 and June 2021; six grab samples were carried out at three sampling stations. Different indices were evaluated based on the benthic community characteristics (species richness, abundance, density, ecological and trophic groups, and the biotic index) and indicator species. An inventory of the macrobenthic fauna of the farm allowed us to identify 6 phyla, 10 classes, 48 families, 106 genera, and 138 species, with a total of 45960 ind/m2. The benthic assemblage is characterised by the dominance of the species Abra alba, Salvatoria clavata, Caecum spp., and Bittium spp. The results of the four benthic indices (the Shannon-Weaver diversity index [H′], the AZTI Marine Biotic Index [AMBI], the multivariate AZTI Marine Biotic Index [M-AMBI], and the BENTIX) indicated that that the sampling stations have a moderate and good ecological status. These results were confirmed by the abundance/biomass comparison curves and geometric abundance class methods. This study provides the first inventory and represents the reference state of the soft-bottom communities of the aquaculture farm. The findings also indicate that the macrobenthic assemblage is excellent indicator of the ecological status.

Effect of Environmental Variables on Zooplankton in Various Habitats of the Nile River

The present study investigated the effect of environmental variables on the abundance and distribution of zooplankton in different habitats along the Nile River in Shattura Village. Zooplankton samples were collected from three distinct sites along the Nile River in Shattura Village, each exhibiting different environmental characteristics: Site 1 with vegetation, site 2 lacking vegetation, and site 3 being a drain canal. The study spanned from spring 2020 to winter 2021, during which the physico-chemical parameters of the water were analyzed. Rotifera constituted the majority of the zooplankton (54.73%), followed by Cladocera (20.59%), Copepoda (13.1%), and Ostracoda (8.9%). Among the 52 identified zooplankton species, Rotifera comprised 18 species, Cladocera 13 species, Copepoda 10 species, and Ostracoda 11 species. Site 1 exhibited the highest zooplankton density (44.08%), attributed to the presence of vegetation, followed by site 3 (37.18%), influenced by agricultural drains, and site 2 had the lowest density (18.73%). Zooplankton abundance peaked in summer and declined in winter. Notably, Rotifera abundance increased in populated sites (site 3), whereas other zooplankton groups thrived in less populated areas. Correlation analyses revealed positive associations between Rotifera and Cladocera with electric conductivity, total dissolved solids (TDS), chloride (Cl), calcium (Ca), and sulfate (SO4). Conversely, Copepoda showed positive correlations with water transparency, pH, dissolved oxygen, and biological oxygen demand (BOD). Overall, seasonal variations significantly impacted the zooplankton community, with Rotifera dominating and Ostracoda being the least abundant. High values of the Shannon–Weaver diversity index, richness, and evenness suggested ample food resources and favorable growth conditions. Transparency, conductivity, pH, dissolved oxygen, and BOD were identified as the key influencing parameters on zooplankton abundance. Additionally, vegetation and agricultural drains strongly influenced total zooplankton levels.

Dynamics of fish community structure in the Yeosu Coast, Korea: A comprehensive analysis of daily set-net catch data during 2008–2022

This study focuses on the Yeosu Coast, a critical ecological and economic zone on the Korean Peninsula. We conducted a comprehensive analysis of fish data obtained from daily set nets for the period of 2008–2022 (excluding 2017) to investigate variations in fish composition and community structure over a 15-year period. The catches were characterized by a prevalence of warm-water fish species, reflecting the temperate and subtropical character of the Yeosu Coast. The total catch during the study period was 3210.8 tonnes, with 2010 and 2016 registering the highest and lowest catches, respectively. Our analysis identified sea surface temperature as a primary factor correlated with these changes in species composition. The two dominant species, Scomberomorus niphonius (Cuvier, 1832) and Engraulis japonicus Temminck et Schlegel, 1846 together accounted for a remarkable 78.9% of the total catch. Notably, the Shannon–Weaver diversity index values were lower in 2015 than in 2008, indicating potential shifts in the community structure. Our analysis identified sea surface temperature as the most dominant factor that influenced these changes in species composition. Furthermore, we highlight the significant threats posed by climate change and the increasing number of jellyfish challenging fisheries on the Yeosu Coast. These threats have the potential to result in diminished set-net catches and declining biodiversity within this valuable ecosystem. Our findings underscore the importance of monitoring and addressing these ecological shifts to ensure the long-term sustainability of Yeosu Coast fisheries.

Root Architectural Adaptations to Phosphorus Deficiency: Unraveling Genotypic Variability in Wheat Seedlings

Understanding the changes in the root system architecture of bread wheat under phosphorus (P)-limited conditions is critical for identifying specific traits contributing to improved P uptake. Phenotypic variability in root, biomass, and P index-related traits among 204 diverse wheat genotypes at the seedling stage was examined under low and optimum P treatments. Strong genotypic and phenotypic associations between P utilization efficiency (PUtE) and total root volume, dry weight of root and shoot, total P uptake, and total plant biomass were observed under optimum P. Under low P, strong positive correlations between PUtE and total root length, total root volume, total surface area, and total biomass were observed, while it was negatively correlated with average diameter. These traits exhibited medium to high heritability. Under low P, average root diameter, primary root length, root mass ratio, total root tips, and surface area showed high Shannon–Weaver diversity index (H’) values (>0.79). The agglomerative hierarchical clustering analysis grouped the genotypes into four distinct clusters. The best performing genotypes in Clusters I and II indicated their strong relationship with P use efficiency due to higher percent increases in total root length, total surface area, total root volume, total root tips, total biomass, P efficiency ratio, specific root length, and PUtE under low P as compared to optimum P conditions. The present study identified specific root system architectural traits and P use-efficient genotypes (SHANGHAI, Pavon F76, BWL 5233, SONALIKA, KHARCHIA LOCAL, WH 102, BWL 4425, HD 2888.2, CBW 12, MN75136/PGO, KRL 19, and WH 1022) associated with efficient P uptake and utilization. These identified genotypes and traits may be useful in wheat breeding programs to develop P-efficient varieties with better adaptations for sustainable agriculture.

The impact of Eucalyptus plantations on herpetofaunal diversity, Maputo National Park, Mozambique

ABSTRACT Exotic afforestation has proven detrimental to biodiversity in general, however only a few studies documenting the impact of timber plantations on herpetofaunal diversity have been published within a southern African context. To determine if variations in herpetofaunal species assemblages could be detected between derelict Eucalyptus plantations, cleared plantation woodlots, and untransformed sand thicket vegetation, a pitfall and funnel trap survey was conducted in coastal southern Mozambique. Herpetofaunal species richness for derelict Eucalyptus plantations was 13 ± 2.24 species, untransformed sand thicket vegetation 17 ± 2.34 species and cleared plantation woodlots 18 ± 3.14 species. Both Shannon-Weaver and Simpson Diversity Indices estimated the highest herpetofaunal species diversity in untransformed sand thicket vegetation and the lowest diversity in derelict Eucalyptus plantations. The herpetofaunal species assemblages of derelict Eucalyptus plantations and natural sand thicket vegetation were least similar (0.507 ± 0.041), while cleared plantation woodlots and derelict Eucalyptus plantations were most similar (0.753 ± 0.032) in terms of herpetofaunal community composition. In contrast to our expectations, significantly higher capture rates were reported for a fossorial anuran in derelict Eucalyptus plantations compared to both cleared plantation woodlots and untransformed sand thicket vegetation, which requires further investigation and discussion. As with most other studies investigating the effects of exotic timber plantations on biodiversity, our results indicate that the detectable herpetofaunal diversity decreased in Eucalyptus plantations when compared to natural or cleared plantation woodlots. Subsequently it would seem as though the active clearing of dilapidated timber plantations as part of rehabilitation efforts may positively affect herpetofaunal diversity.

Composição e diversidade florística do banco de sementes de um inselbergue no semiárido paraibano

ABSTRACT The objective of this study was to evaluate the seed bank composition and floristic diversity, as well as the degree of vegetation similarity at different altitudes (base, middle, and top layers) of the Espinho Branco Inselberg, Patos, PB, Brazil. Forty-seven litterfall-soil samples (0-5 cm soil layer) were collected and placed on 95 perforated plastic trays to allow drainage of excess irrigation water. The trays were identified and distributed on benches in a shaded environment in the forest nursery at the Federal University of Campina Grande (UAEF/CSTR/UFCG), with a sunlight reduction factor of 50%. The emerged plants were classified by popular names, grouped according to family, genus, species, and plant type (herbaceous, sub-shrub, shrub, tree, and climber). Diversity and richness were evaluated using the Shannon-Weaver diversity and the Pielou equitability indices, and the similarity was determined using the Jaccard Index. The floristic composition of the collected samples showed 4,616 individuals from 40 families, 96 genera, and 111 species. The family Fabaceae had the highest number of species, followed by Euphorbiaceae, Malvaceae, and Poaceae. The predominant plant type was herbaceous. Cyperaceae, Onagraceae, and Poaceae were the most representative families in number of individuals. The Shannon-Weaver diversity and Pielou equitability indices were 2.92 and 0.62, respectively, and the Jaccard index was 0.93; the base layer had the greatest floristic richness. This work contributes with information to further researches on floristic diversity and richness and improves scientific studies in this field.

Seasonal Distribution of Copepods as Influenced by Physicochemical Parameters in Khanki Headworks, Pakistan

Copepods are tiny aquatic animals. Their role in aquatic food chains is very crucial as they are involved in organic matter circulation and energy transfer between different trophic levels. They are important source of food for fish larvae and zooplanktivorous fish. Objective: To assess the influence of environmental variables on the abundance, diversity and seasonal variations of planktonic copepods in Khanki Headworks, Pakistan. Methods: For the analysis of environmental variables monthly water samples from four selected sites were collected for a period of one year (February 2021 to January 2022). Environmental variables were analyzed in laboratory by following standard procedures. Month wise samples of copepods were collected with planktonic net (mesh size: 37µm) from four locations (each with 3 sub-sites). Results: In total, 7 species of Copepods belonging to 4 genera were identified from February 2021 to January 2022. Mesocyclops was observed as the most diverse genus (4 species), while Mesocyclops edax was the most prevalent copepod species. Population density and biodiversity were highest in June and minimum in January. Shannon-Weaver diversity index described greater diversity among copepod species in June. Pearson correlation and canonical correspondence analysis (CCA) revealed that electrical conductivity (EC), temperature, turbidity, pH and dissolved oxygen (DO) were important environmental variables affecting the biodiversity and density of copepods. Conclusions: This investigation elucidated that physicochemical parameters generally regulate the population dynamics of Copepods.

Uterine microbial profiles in healthy postpartum dairy cows do not vary with sampling techniques or phases of estrous cycle

In this study, we aimed to compare uterine microbial profiles in postpartum dairy cows, determined by bacteriological culture and next-generation sequencing, using three uterine sampling techniques (swab, cytobrush, and lavage) and induced phases of the estrous cycle (estrus and diestrus). Fifteen healthy postpartum dairy cows at 53 ± 5 days postpartum were enrolled in the study. Uterine samples were collected during a fixed-time artificial insemination protocol. Viable bacteria were aerobically cultured from part of each sample, and bacterial isolates were identified through Sanger sequencing of the 16S rRNA gene. Total genomic DNA was extracted from the remainder of undiluted samples to quantify bacterial load using 16S rRNA qPCR and characterize the microbiome by metagenomic sequencing of the V1–V3 region of the 16S rRNA gene. Microbial profiles and composition were analyzed using the Shannon-Weaver diversity index and principal component analysis, respectively. Out of 87 samples, 88 % (77/87) were culture positive. The proportion of culture-positive uterine samples did not differ between sampling techniques (P = 0.39) or estrous cycle phases (P = 0.99). However, swab, cytobrush, and lavage techniques yielded 1.5, 9 and 9 times greater bacterial loads (P < 0.01), respectively, during diestrus than estrus phase. Moreover, during diestrus phase, the cytobrush method yielded 3 and 6 times more bacteria (P < 0.01) than both the lavage and swab methods. The most abundant bacterial genera identified from both bacteriological culture and metagenomic sequencing were Bacillus and Enterococcus, regardless of sampling technique or phases of the estrous cycle. Bacterial genera in moderate to low abundance through metagenomic sequencing included Streptococcus, Oscillospiraceae, and Lachnospiraceae. Notably, the uterine microbial profiles and composition, determined by metagenomic sequencing, did not differ by sampling techniques (P = 0.55 and P = 0.60, respectively) or estrous cycle phases (P = 0.34 and P = 0.17, respectively). In conclusion, our results suggest that any of the sampling techniques can be reliably used to study the uterine microbiome of healthy cows at random phases of the estrous cycle. However, it is important to consider potential differences in bacterial yield as a confounding factor.

Multi-environment phenotyping of linseed (Linum usitatissimum L.) germplasm for morphological and seed quality traits to assemble a core collection

Linseed or flax (Linum usitatissimum L.) is one of the most ancient industrial crops domesticated for oilseed and natural fiber. India is one of the two proposed centers of origin of linseed and harbours high genetic diversity. The Indian Council of Agricultural Research-National Bureau of Plant Genetic Resources (ICAR-NBPGR) conserves one of the largest base collections of Linum with around 2800 germplasm accessions at National Genebank, of which 2576 are the unique accessions of cultivated linseed and were characterized for 10 qualitative and 26 quantitative traits and the resultant multi-environment data along with passport information was used to develop a multipurpose core collection. Initially, five different core sets were derived using the core collection assembler tool ‘Core Hunter 3’ by optimization of average genetic distances between each accession and nearest entry in the core (A-NE) and the average distance between each entry and nearest neighbouring entry (E-NE). These five core sets were subjected to different quality evaluation indices to select one set that best represents the maximum genetic diversity and representativeness present in the entire tested collection. The Core collection-4, developed with weightage of E-NE and A-NE in the ratio of 0.7–0.3 was chosen as the best core collection as it exhibited desirable genetic distance, variance difference percentage (VD; 85%), coincidence rate of range (CR; 91.66%) and variable rate of coefficient of variance (VR; 117.76%), which were more than threshold value of VD (80%), CR (80%), and VR (100%) required for an optimally good core collection. Several summary statistics, Kullback-Leibler distance and Shannon Weaver diversity index indicated similar trait distribution patterns among the chosen core set and the entire collection. Correlogram and principal component analysis revealed that trait associations and their magnitude were conserved for most of the traits in the chosen best core collection. The development of this multipurpose core collection is expected to cater to the needs of linseed breeders and germplasm curators to pave the way for expedited access to genetically diverse and agronomically important material for trait introgression.