Mean Genetic Diversity Research Articles

Genetic diversity of Sinapis arvensis L. (wild mustard) in Türkiye determined by microsatellite markers

Wild mustard (Sinapis arvensis L.) is a self-fertilizing weed species that exerts negative impacts on wheat production and herbicides are intensively used to manage it. Cross-fertilization may lead to genetic differentiation in this species. Therefore, this study investigated genetic diversity among wild mustard populations collected from wheat fields across various regions in Türkiye. Genetic variation was evaluated using 5 simple sequence repeat (SSR) markers in populations collected from 30 different locations. Populations were analyzed using UPGMA (unweighted pair group method with arithmetic mean) and principal component analysis (PCA). The mean genetic diversity (GD) and polymorphism information content (PIC) values were 0.752 and 0.844, respectively. High genetic variability was recorded among populations within geographic locations. The populations were categorized into two major groups by UPGMA. There was no apparent geographic isolation among tested populations, which displayed a high degree of variability. The primary source of this variability is thought to be the adaptability of wild mustard seeds dispersed through various methods across diverse locations. Despite being a predominantly self-pollinating species, wild mustard may also employ some cross-pollination mechanisms. In conclusion, SSR markers proved useful in determining genetic diversity in outcrossing species, especially where no prior genotypic information is available. The study suggests that genetic diversity is maintained in wild mustard populations even with rotational farming practices and intensive use of herbicides.

Patterns in the genetic structure of 49 lowland rain forest tree species co‐distributed on opposite sides of the northern Andes

AbstractThe Andes are a major dispersal barrier for lowland rain forest plants and animals, yet hundreds of lowland tree species are distributed on both sides of the northern Andes, raising questions about how the Andes influenced their biogeographic histories and population genetic structure. To explore these questions, we generated standardized datasets of thousands of SNPs from paired populations of 49 tree species co‐distributed in rain forest tree communities located in Panama and Amazonian Ecuador and calculated genetic diversity (π) and absolute genetic divergence (dXY) within and between populations, respectively. We predicted (1) higher genetic diversity in the ancestral source region (east or west of the Andes) for each taxon and (2) correlation of genetic statistics with species attributes, including elevational range and life‐history strategy. We found that genetic diversity was higher in putative ancestral source regions, possibly reflecting founder events during colonization. We found little support for a relationship between genetic divergence and species attributes except that species with higher elevational range limits exhibited higher dXY, implying older divergence times. One possible explanation for this pattern is that dispersal through mountain passes declined in importance relative to dispersal via alternative lowland routes as the Andes experienced uplift. We found no difference in mean genetic diversity between populations in Central America and the Amazon. Overall, our results suggest that dispersal across the Andes has left enduring signatures in the genetic structure of widespread rain forest trees. We outline additional hypotheses to be tested with species‐specific case studies.

Molecular Discrimination for Two Anadenanthera Species of Seasonally Dry Tropical Forest Remnants in Brazil

Anadenanthera colubrina (Acol) and Anadenanthera peregrina (Aper) (Fabaceae) are two species popularly known as “angicos” that occur in seasonally dry tropical forest (SDTR) remnants in Brazil. Since many of the morphological characteristics of Anadenanthera species are superimposed and species-specific characteristics are difficult to observe, their identification is complex. Therefore, in this research, a set of ISSR (Inter-Simple Sequence Repeat Polymorphic DNA) molecular markers was standardized, aiming to characterize A. colubrina and A. peregrina species and study the genetic diversity of three populations of each species located within a fragmented landscape in São Paulo State, southeastern Brazil. Seven ISSR markers (UBC 2, 820, 851, 858, 864, 866, and 886) that show polymorphism for both species were used. The Bayesian cluster, PCoA and dendrogram analysis show that the total sample divides into two groups corresponding to each species. Also, a genetic divergence (Gst = 0.143) and a high number of migrants per generation (Nm = 3.0) were detected between them. The Acol populations showed significantly higher values for mean genetic diversity (h = 0.30) than Aper (h = 0.25) (p < 0.05). The ISSR marker UBC2250bp showed species-specific electrophoretic fingerprints for both species. The molecular tools generated herein support the conservation of Anadenanthera sp. and the restoration of vegetation where the species naturally occurs.

Genetic diversity analysis and fingerprinting of 175 Chimonanthus praecox germplasm based on SSR molecular marker

The elucidation of resources pertaining to the Chimonanthus praecox varieties and the establishment of a fingerprint serve as crucial underpinnings for advancing scientific inquiry and industrial progress in relation to C. praecox. Employing the SSR molecular marker technology, an exploration of the genetic diversity of 175 C. praecox varieties (lines) in the Yanling region was conducted, and an analysis of the genetic diversity among these varieties was carried out using the UPDM clustering method in NTSYSpc 2.1 software. We analyzed the genetic structure of 175 germplasm using Structure v2.3.3 software based on a Bayesian model. General linear model (GLM) association was utilized to analyze traits and markers. The genetic diversity analysis revealed a mean number of alleles (Na) of 6.857, a mean expected heterozygosity (He) of 0.496 3, a mean observed heterozygosity (Ho) of 0.503 7, a mean genetic diversity index of Nei՚s of 0.494 9, and a mean Shannon information index of 0.995 8. These results suggest that the C. praecox population in Yanling exhibits a rich genetic diversity. Additionally, the population structure and the UPDM clustering were examined. In the GLM model, a total of fifteen marker loci exhibited significant (P < 0.05) association with eight phenotypic traits, with the explained phenotypic variation ranging from 14.90% to 36.03%. The construction of fingerprints for C. praecox varieties (lines) was accomplished by utilizing eleven primer pairs with the highest polymorphic information content, resulting in the analysis of 175 SSR markers. The present study offers a thorough examination of the genetic diversity and SSR molecular markers of C. praecox in Yanling, and establishes a fundamental germplasm repository of C. praecox, thereby furnishing theoretical underpinnings for the selection and cultivation of novel and superior C. praecox varieties, varietal identification, and resource preservation and exploitation.

Deciphering the genetic diversity and population structure of wild barley germplasm against corn leaf aphid, Rhopalosiphum maidis (Fitch)

Corn-leaf aphid (CLA-Rhopalosiphum maidis) is a major insect pest of barley (Hordeum vulgare) causing yield loss upto 30% under severe infestation. Keeping in view of the availability of very few sources of CLA resistance in barley, the present investigation was framed to assess the genetic diversity and population structure of 43 wild barley (H. vulgare subsp. spontaneum) genotypes using eight microsatellite markers against R. maidis. Three statistical methods viz. multivariate-hierarchical clustering, Bayesian clustering and PCoA, unanimously grouped genotypes into three subpopulations (K = 3) with 25.58% (SubPop1-Red), 39.53% (SubPop2-Green) and 34.88% (SubPop3-Blue) genotypes including admixtures. Based on Q ≥ 66.66%, 37.20% genotypes formed a superficial “Mixed/Admixture” subpopulation. All polymorphic SSR markers generated 36 alleles, averaging to 4.5 alleles/locus (2–7 range). The PIC and H were highest in MS31 and lowest in MS28, with averages of 0.66 and 0.71. MAF and mean genetic diversity were 0.16 and 89.28%, respectively. All these parameters indicated the presence of predominant genetic diversity and population structure amongst the studied genotypes. Based on AII, only 6 genotypes were found to be R. maidis resistant. SubPop3 had 91.66% (11) of the resistant or moderately resistant genotypes. SubPop3 also had the most pure genotypes (11), the least aphid infestation (8.78), and the highest GS (0.88), indicating its suitability for future R. maidis resistance breeding initiatives.

Generation Mean Analysis, Heterosis, and Genetic Diversity in Five Egyptian Faba Beans and Their Hybrids

The faba bean (Vicia faba L.) is a major legume crop; thus, it is important to apply various biometrical techniques to develop the most efficient breeding procedures to face biotic and abiotic stressors. During the four consecutive winter seasons of 2017–2021, five populations of five faba bean hybrids were studied at Sakha agricultural research station in Egypt. Five basic generations, including two parents (P1 and P2) and the first, second, and third generations, were studied. This analysis found significant variations between generations in all attributes studied in all crosses (P1, P2, F1, F2, and F3). Sakha 4 was the earliest parent (138 days) based on the maturity date, whereas Giza 40 had the most significant number of pods and seeds per plant (25.68–78.94), and Giza 716 had the tallest plant height (124.00 cm). Giza 843 and Sakha 4 had the highest seed yield per plant values (62.84 g and 61.77 g). The data demonstrated highly substantial heterosis in the favorable direction over mid and better parents for all features, except for the number of branches in Cross 3 (Giza 40 × Giza 843) over mid and better parents and a maturity date in Cross 1 over mid parents. Contrarily, opposite-direction dominance and dominance × dominance effects increased narrow-sense heredity. Broad-sense heritability values for all examined characteristics were high in all crosses, ranging from 90.24% to 97.67%. In both Crosses 5 (Giza 716 × Qahera 4) and 3, genetic advance through selection ranged from 1.73% at the maturity date to 95.12% for seed yield per plant. Cross 3 (Giza 40 × Giza 843) had the greatest number of branches, pods, and seeds per plant. In conclusion, this study advances our understanding of employing faba beans in breeding programs.

High-density DArTSeq SNP markers revealed wide genetic diversity and structured population in common bean (Phaseolus vulgaris L.) germplasm in Ethiopia

IntroductionCommon bean is one of the widely consumed food security crop in Africa, Asia, and South America. Understanding genetic diversity and population structure is crucial for designing breeding strategies.MaterialsTwo hundred and eighty-nine germplasm were recently collected from different regions of Ethiopia and introduced from CIAT to estimate genetic diversity and population structure using 11,480 DArTSeq SNP markers.ResultsThe overall mean genetic diversity and polymorphic information content (PIC) were 0.38 and 0.30, respectively, suggested the presence of adequate genetic diversity among the genotypes. Among the geographical regions, landraces collected from Oromia showed the highest diversity (0.39) and PIC (0.30). The highest genetic distance was observed between genotypes collected from SNNPR and CIAT (0.49). In addition, genotypes from CIAT were genetically more related to improved varieties than the landraces which could be due to sharing of parents in the improvement process. The analysis of molecular variance revealed that the largest proportion of variation was due to within the population both in geographical region (63.67%) and breeding status (61.3%) based classification. Model-based structure analysis delineated the 289 common bean genotypes into six hypothetical ancestoral populations.ConclusionsThe genotypes were not clustered based on geographical regions and they were not the main drivers for the differentiation. This indicated that selection of the parental lines should be based on systematic assessment of the diversity rather than geographical distance. This article provides new insights into the genetic diversity and population structure of common bean for association studies, designing effective collection and conservation for efficient utilization for the improvement of the crop.

Genetic diversity varies with species traits and latitude in predatory soil arthropods (Myriapoda: Chilopoda).

To investigate the drivers of intra-specific genetic diversity in centipedes, a group of ancient predatory soil arthropods. Asia, Australasia and Europe. Present. Centipedes (Class: Chilopoda). We assembled a database of 1245 mitochondrial cytochrome c oxidase subunit I sequences representing 128 centipede species from all five orders of Chilopoda. This sequence dataset was used to estimate genetic diversity for centipede species and compare its distribution with estimates from other arthropod groups. We studied the variation in centipede genetic diversity with species traits and biogeography using a beta regression framework, controlling for the effect of shared evolutionary history within a family. A wide variation in genetic diversity across centipede species (0-0.1713) falls towards the higher end of values among arthropods. Overall, 27.57% of the variation in mitochondrial COI genetic diversity in centipedes was explained by a combination of predictors related to life history and biogeography. Genetic diversity decreased with body size and latitudinal position of sampled localities, was greater in species showing maternal care and increased with geographic distance among conspecifics. Centipedes fall towards the higher end of genetic diversity among arthropods, which may be related to their long evolutionary history and low dispersal ability. In centipedes, the negative association of body size with genetic diversity may be mediated by its influence on local abundance or the influence of ecological strategy on long-term population history. Species with maternal care had higher genetic diversity, which goes against expectations and needs further scrutiny. Hemispheric differences in genetic diversity can be due to historic climatic stability and lower seasonality in the southern hemisphere. Overall, we find that despite the differences in mean genetic diversity among animals, similar processes related to life-history strategy and biogeography are associated with the variation within them.

Molecular assessment of the taxonomic status of pine vole species Microtus subterraneus and Microtus majori in southeastern Europe and Turkey

Intra– and inter–specific phylogenetic relationships and the taxonomic status of pine vole populations have been controversial for years, and cryptic species are thought to exist, especially concering the species' distribution area. To clarify the taxonomic status of Turkish populations we analysed mitochondrial (cytochrome–b and cytochrome oxidase–I) and nuclear (interphotoreceptor retinoid binding protein) gene markers, adding GenBank data from Europe and Caucasia. Considering the data obtained based on mean genetic distance, genetic diversity and fixation index values, Bayesian trees and Median–joining networks, we found that M. subterraneus and M. majori are valid species which have diverged since 1.28 Mya. Findings also suggested that although Anatolian, Thracian (Turkish Thrace and Greece) and European populations of M. subterraneus and Anatolian and Caucasian populations of M. majori have been in the process of divergency since 0.528–0.337 Mya correspond to the Pleistocene glacial periods, these intrapopulations do not appear to be different species.Besides, considering the high intraspecific variation in M. subterraneus, it remains likely that new species could be identified in future studies.

Diversidade genética, produtividade e qualidade de frutos de caqui nos trópicos

Abstract The objective of this work was to determine the genetic diversity, yield, and fruit quality of persimmon genotypes grown in the tropics, in order to select promising genetic materials. DNA extraction was performed on young leaves of 19 persimmon genotypes. For pomological characterization, 15 genotypes were selected. From each genotype, 50 fruit at the physiological maturity stage were harvested in the morning, in order to determine the following parameters: physicochemical characteristics; and the productive variables number of fruit per plant, average fruit fresh mass, average yield, and estimated average yield in two seasons. Twenty SSR markers were tested, out of which 12 were selected to evaluate genetic similarity, which allowed of the identification of distinct groups. The mean genetic diversity value found was 0.41, which is an indicative of low diversity among the analyzed persimmon genotypes. The 'Guiombo', 'Iapar 125', 'Kakimel', 'Mikado RJ', 'Rama Forte Tardio', and 'Taubaté' genotypes show a high yield. The genotypes classified as pollination-constant astringent ('Pomelo', 'Regina', 'Rubi', and 'Taubaté') and those classified as pollination-variant astringent ('Rama Forte', 'Guiombo', and 'Cereja') are potential materials for selection and genetic breeding programs due to their excellent fruit physicochemical characteristics. The investigation through molecular markers is an efficient approach to study the genetic diversity of persimmon genotypes grown in the tropics.

Genetic divergence at species boundaries of the dolphinfish (Coryphaena hippurus) in the Tropical Eastern Pacific.

Marine species constitute commercially important resources, and knowledge about mechanisms that shape phylogeographic patterns and genetic structure provides valuable information for conservation. The dolphinfish, Coryphaena hippurus, is one of the most important species caught in the Tropical Eastern Pacific (TEP). However, the lack of consensus about the existence of genetically differentiated populations in the area has hindered the adoption of management strategies to ensure its viability. We assessed genetic variation and phylogeographic structure using two mitochondrial genes and 14 nuclear DNA microsatellite loci. Population genetic tools were used to characterize the spatial distribution of genetic variation of C. hippurus in the TEP, evaluate the extent of connectivity between dolphinfish populations, infer potential barriers to gene flow, and test for signals of contemporary and historical demographic expansions. Mitochondrial DNA sequences showed genetic homogeneity across locations in the TEP, as well as a strong signal of population expansion dated to the late Pleistocene. In contrast, nuclear microsatellite markers resolved four genetically distinct groups with a remarked genetic differentiation between the most distant locations, at the northern and southern boundaries of the species' range. High mean genetic diversity was found at all localities (Hs = 0.66-0.81). Notwithstanding, positive F IS and low effective population size (Ne = 77.9-496.4) were also recorded. The distribution of genetic variation could be related to expansion-contraction cycles following seasonal temperature changes at transitional areas, promoting population subdivisions. However, we cannot rule out the effect of oceanographic dynamics to the observed patterns. Although this marine species remains highly abundant despite commercial exploitation, the low Ne values are of conservation concern and must be considered in fishery management plans.

Genetic diversity and population structure analyses of South African Bambara groundnut (Vigna subterranea [L]. Verdc.) collections using SNP markers

• Bambara groundnut productivity in South Africa is low (0.62 t/ha) compared to the attainable yield of the crop reaching up to 3 t/ha. • The low productivity is attributable to a lack of improved and high yielding cultivars that are locally bred and adapted in the country. • This paper presents baseline information on Bambara groundnut genetic profile of South African collections for effective breeding and conservation. • The magnitude of the genetic diversity and population structure of Bambara groundnut collections of South Africa using high throughput single nucleotide polymorphisms (SNP) markers are highlighted to guide current and future Bambara groundnut research and development by selection genetically unique genotypes for breeding. Bambara groundnut ( Vigna subterranea [L.] Verdc) is a highly nutritious grain legume with a significant potential to develop various commercial food and feed products. It is a resilient crop able to grow under harsh climates and poor soil conditions. Bambara groundnut productivity in South Africa is low (0.62 t/ha) compared to the attainable yield of the crop reaching up to 3 t/ha. The low productivity is attributable to a lack of improved and high yielding cultivars that are locally bred and adapted in the country. Genetically diverse and locally adapted Bambara groundnut landrace varieties and exotic collections are present in South Africa for strategic breeding to improve yield and yield-related traits and nutritional quality. The objective of this study was to determine the magnitude of the genetic diversity and population structure of Bambara groundnut collections of South Africa using high throughput single nucleotide polymorphisms (SNP) markers. Ninety-three genotypes were assessed using genotyping with 2286 SNP markers and some unique complementary morpho-agronomic traits of the crop. The mean genetic diversity value was 0.32, revealing moderate genetic differences among the assessed genotypes. Cluster and structure analyses grouped the test genotypes into two distinct categories. Further, the analysis of molecular variance partitioned the total genetic variation into among genotypes (90%), within genotypes (8%) and among populations (2%). The results revealed two heterotic groups for hybridization and selection programs. The following unique genotypes were selected: ARC Bamb 37 (with spreading growth type), ARC Bamb 49 (bunch type), ARC Bamb 61 (semi-bunch) and ARC Bamb 83 (spreading) using the SNP markers and desirable agronomic traits. The study provided new insight on Bambara groundnut genetic profiles of South African collections which will assist in conservation strategy and management of the crop for effective breeding.

Genome-Wide Genetic Diversity and Population Structure of Local Sudanese Sheep Populations Revealed by Whole-Genome Sequencing

Local Sudanese sheep populations inhabiting diverse environmental conditions and holding opposing morphologies provide opportunities for molecular-genetic research. Characterizing their genome is crucial for sustainable breeding improvement and targeting favorable genes in breeding programs. However, the genome of these sheep populations, which comprises several subtypes, remains uncharacterized using whole-genome sequence data. This study aimed to elucidate genome-wide genetic diversity and population structure of 11 local Sudanese sheep populations, namely, Hammari, Kabbashi, Meidobe, Ashgar, Dubasi, Watish, Bega, Naili, Fulani, Zagawi, and Garag. Ninety whole blood samples were collected, and we extracted DNA using a Qiagen DNeasy® extraction kit. We used the Illumina HiSeq 2000 platform to sequence all the DNA samples. We included whole-genome sequence data of three Ethiopian sheep (Doyogena, Kefis, and Gafera) and one Libyan sheep (Libyan Barbary) in the study to infer the genetic relationships of local Sudanese sheep populations from a continental perspective. A total of 44.8 million bi-allelic autosomal SNPs were detected; 28.5% and 63.3% occur in introns and intergenic regions, respectively. The mean genetic diversity ranged from 0.276 for Garag to 0.324 for Kabbashi sheep populations. The lowest FST estimates were observed between Kabbashi and Ashgar and the highest between Bega and Fulani local Sudanese sheep populations. The principal component and population structure analyses of the 11 local Sudanese sheep populations indicated three separate genetic groups categorized following their tail morphotype, geographical distribution, and population subtype. The thin-tailed local Sudanese sheep populations exhibited independent clustering from the fat-tailed Ethiopian and Libyan sheep. We also observed distinct clustering between the fat-tailed Ethiopian and Libyan sheep. The present study’s findings demonstrated the population structure and principal components related to tail morphotype, geographical distribution, and population subtype of local Sudanese sheep populations. A clear signature of admixture was observed among the studied local Sudanese sheep populations.

Genetic structure of the pine needle pathogen Lecanosticta acicola in Lithuania and northern Poland

AbstractBrown spot needle blight, a disease of pine trees caused by the pathogenic fungus Lecanosticta acicola, has been known in Lithuania since 2009 and in Poland since 2014, but data on the distribution and population genetics of this needle pathogen were lacking. In order to investigate the genetic diversity, population structure and reproductive mode of L. acicola, 93 isolates were isolated from Pinus mugo needles in 2017–2019 and analysed using 11 microsatellite and two mating‐type markers. This study revealed 47 unique multilocus haplotypes among all investigated isolates; two genetically distinct populations of L. acicola (LIT‐E and LIT‐W) were identified in Lithuania and one population (POL‐N) in the coastal region of northern Poland. The most genetically diverse population was the LIT‐E population occurring in the eastern continental part of Lithuania, followed by the LIT‐W population spreading along the western Baltic Sea coast. All populations in both countries are characterized by low genetic diversity and contain clones, with the northern Polish population having the lowest mean genetic diversity and the greatest clonal fraction. Both mating types are present in the Lithuanian populations, demonstrating that sexual reproduction is possible, whereas only one mating type is present in the Polish population. However, the sexual stage (teleomorph) has not yet been found on infected needles, and asexual reproduction predominates. High gene flow from the eastern Lithuanian population to the northern Poland population was found, suggesting that the Polish coastal population may have been introduced from the central part of Lithuania and did not spread naturally along the Baltic Sea coast from the western Lithuanian population.

Genotyping-by-Sequencing Based Molecular Genetic Diversity of Pakistani Bread Wheat (Triticum aestivum L.) Accessions.

Spring wheat (Triticum aestivum L.) is one of the most imperative staple food crops, with an annual production of 765 million tons globally to feed ∼40% world population. Genetic diversity in available germplasm is crucial for sustainable wheat improvement to ensure global food security. A diversity panel of 184 Pakistani wheat accessions was genotyped using 123,596 high-quality single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing with 42% of the SNPs mapped on B, 36% on A, and 22% on D sub-genomes of wheat. Chromosome 2B contains the most SNPs (9,126), whereas 4D has the least (2,660) markers. The mean polymorphic information content, genetic diversity, and major allele frequency of the population were 0.157, 0.1844, and 0.87, respectively. Analysis of molecular variance revealed a higher genetic diversity (80%) within the sub-population than among the sub-populations (20%). The genome-wide linkage disequilibrium was 0.34 Mbp for the whole wheat genome. Among the three subgenomes, A has the highest LD decay value (0.29 Mbp), followed by B (0.2 Mbp) and D (0.07 Mbp) genomes, respectively. The results of population structure, principal coordinate analysis, phylogenetic tree, and kinship analysis also divided the whole population into three clusters comprising 31, 33, and 120 accessions in group 1, group 2, and group 3, respectively. All groups were dominated by the local wheat accessions. Estimation of genetic diversity will be a baseline for the selection of breeding parents for mutations and the genome-wide association and marker-assisted selection studies.

Improving plant-based genotoxicity bioassay through AFLP technique for trace metal-contaminated water: insights from Myriophyllum aquaticum (Vell.) Verdc. and Cd

In this work, we evaluated whether the species Myriophyllum aquaticum (Vell.) Verdc. can be a promising material for devising reliable eco-toxicological tests for Cd-contaminated waters. Plants of M. aquaticum were exposed to Cd, using different concentrations (1 mg L−1, 2.5 mg L−1, 5 mg L−1, and 10 mg L−1; experiment 1) and exposure times (2.5 mg L−1 for 3 days, 7 days, 14 days, and 21 days; experiment 2). Plant growth and Cd accumulation were monitored during the treatment period, and Cd genotoxicity was assessed by analyzing Cd-induced changes in the AFLP fingerprinting profiles using famEcoRI(TAC)/MseI(ATG) and hexEcoRI(ACG)/MseI(ATG) pairs of primers. Root and shoot growth was reduced already at the lowest Cd concentration used (about 20% reduction for roots and 60% for shoots at 1 mg L−1; experiment 1) and after 7 days (about 50% reduction for roots and 70% for shoots; experiment 2). The primer combinations produced 154 and 191 polymorphic loci for experiments 1 and 2, respectively. Mean genetic diversity (He) reduction among the treatment groups was observed starting from 2.5 mg L−1 (He 0.211 treated vs 0.236 control; experiment 1) and after 3 days (He 0.169 treated vs 0.261 control; experiment 2), indicating that results obtained from AFLP profiles did not match with plant growth measurements. Therefore, our results showed that M. aquaticum proved to be a suitable model system for the investigation of Cd genotoxicity through AFLP fingerprinting profile, whereas the more classic eco-toxicological tests based only on biometric parameters could not correctly estimate the risk associated with undetected Cd genotoxicity.

Genomic analysis and finding of candidate genes for Nilaparvata lugens (stål) resistance in Indian pigmented and other indigenous rice genotypes

Rice production is facing serious threats due to frequent outbreak of brown plant hopper, Nilaparvata lugens (Stål.) population. Globally, four biotypes of N. lugens has been recorded, of which biotype-4 is the utmost damaging one prevailing in Asian subcontinents particularly in India. Therefore, effective management of N. lugens requires durable resistant rice variety with multiple resistant traits and genes. Hence, in the present study 268 rice genotypes were screened against N. lugens. From initial screening results, 96 genotypes were selected for further genotyping using 93 molecular markers linked to 26 different N. lugens resistant (R) genes. Genetic analysis revealed the mean genetic diversity of 0.275 and polymorphic information content of 0.240 for all 93 markers. Genetic association through cluster and population structure analysis clearly differentiated the 96 genotypes into three major genetic groups with resistant genotypes grouped in a separate cluster. Likewise, Principal co-ordinate analysis supported the above claim with susceptible, moderately resistant and resistant genotypes accommodated in separate components. Further, genetic variation among population showed a 92% variation among individuals of the population and only 8% between populations. Marker trait association via generalized linear model (GLM) and multi linear model (MLM) picked out five markers for their significant association with different phenotypic parameters such as percent damage, nymphal survival, feeding mark and honeydew excretion. Three markers viz. RM19291 (Bph30), RM28472 (Bph18) and RM28449 (Bph17) were common for both GLM and MLM analysis. These identified resistant genes in rice landrace will serves as the source for development of durable resistant variety against N. lugens.

RELATIONSHIP BETWEEN GENETIC AND ENVIRONMENTAL CHARACTERISTICS OF LITHUANIAN POPULATIONS OF PURPLE LOOSESTRIFE (LYTHRUM SALICARIA)

The present study evaluated genetic diversity of Lithuanian populations of Lythrum salicaria in relation to parameters of riparian environment. Growing along Nemunas, Seaside and Lielupė river basins, 15 populations were examined using amplified fragment length polymorphism markers. Molecular data were related to the river basins, type of land use and cover, natural vice versa regulated fragments of the rivers. Population mean genetic diversity parameters were as follows: percentage of polymorphic loci (57.2), expected heterozygosity (0.183), polymorphismc information content (0.218). Mantel test revealed correlation (R2 = 0.0986, p = 0.01) between genetic and geographic distance of populations. Greater genetic diversity within, rather than among populations (ΦPT = 0.213) was observed. According to the Bayesian clustering, studied populations are admixtures of two gene pools. Analysis of molecular variance revealed significant differentiation between populations belonging to distinct river basins, between populations from natural vs. regulated fragments of the rivers.

Phenotypic and Genetic Diversity Evaluation of Sengon (Falcataria moluccana (Miq.) Barneby &amp; JW Grimes) from Solomon Provenance on Progeny Trial in Cirangsad Experimental Forest, West Java

Initial evaluation of phenotypic variability and genetic diversity was conducted on the progeny test of 2 years-old sengon from Solomon provenance, which derived from nine families of mother tree and were then planted in 4 blocks in the Cirangsad Experimental Forest. Phenotypic assessment on eight traits was conducted on 36 trees using a scoring system, while genetic diversity of 15 selected individuals which represented high and low-score phenotypic traits was analyzed using 5 selected RAPD primers. The result on phenotypic assessment showed that family 3 (57.25 points) has the highest average score of phenotypic quality and family 4 has the lowest average score (7.50 points). Furthermore, genetic analysis showed that the low-scoring sengon population had a greater mean genetic diversity (He = 0.2535) than the high-score population (He = 0.2345). The analysis of molecular variance (AMOVA) revealed a significant genetic differences (p-value &lt; 0.001) among high and low-score populations and the dendrogram of genetic distance revealed clustering of individuals having similar superior phenotypic against those having non-superior, indicating the selection based on phenotypes in this study had succeeded in pooling the good quantitative alleles in the selected population. This evaluation results can be used as a reference in determining the best families to produce superior sengon (from Solomon provenance) offspring in the future that have desired adaptability, productivity, and diversity.

Assessment of morpho-genetic diversity of guava (Psidium guajava) hybrids and genotypes

A total of 20 diverse guava genotypes, including the newly bred hybrids were characterized using the morphological, physio-biochemical parameters and microsatellite markers at ICAR-IARI, New Delhi during 2018-19. Most of the qualitative morphological and physio-biochemical parameters had a coefficient of variation value &gt;20%, which indicated substantial diversity. The longest leaves (14.87 cm) were recorded in Lalit, which was statistically at par with Pant Prabhat (14.67 cm), while amongst the hybrids, it is in GH 2018-10 (13.93 cm). The maximum leaf area was recorded in Pant Prabhat (60.33 cm2) while amongst hybrids it was in GH 2018-2 (53.40 cm2). The highest stomatal conductance and net photosynthetic rate was recorded in guava genotype Shweta (9.63 μmol/m2/s) (0.25 mol/m2/sec) while amongst the hybrids it was in GH 2018-8 (8.73μmol/m2/s) (0.26 mol/m2/sec), respectively. The mean genetic diversity indices, viz. major allelic frequency, number of alleles, gene diversity, heterozygosity and polymorphic information content of eight SSRs were 0.497, 3.75, 0.599, 0.071 and 0.542, respectively among the guava genotypes. Furthermore, the eight SSRs based Neighbour-joining (N-J) tree separated the newly bred guava hybrids into different clusters, clades and out-groups.