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Sugarcane (Saccharum spp. hybrids) is a worldwide acclaimed important agricultural crop used primarily for sugar production and biofuel. Sugarcane’s genetic complexity, aneuploidy, and extreme heterozygosity make it a challenging crop in developing improved varieties. The molecular breeding programs promise to develop nutritionally improved varieties for both direct consumption and commercial application. Therefore, to address these challenges, the development of simple sequence repeats (SSRs) has been proven to be a powerful molecular tool in sugarcane. This study involved the collection of 285216 expressed sequence tags (ESTs) from sugarcane, resulting in 23666 unigenes, including 4547 contigs. Our analysis identified 4120 unigenes containing a total of 4960 SSRs, with the most abundant repeat types being monomeric (44.33%), dimeric (13.10%), and trimeric (39.68%). We further chose 173 primers to analyze the banding pattern in 10 sugarcane accessions by PAGE analysis. Additionally, functional annotation analysis showed that 71.07%, 53.6%, and 10.3% unigenes were annotated by Uniport, GO, and KEGG, respectively. GO annotations and KEGG pathways were distributed across three functional categories: molecular (46.46%), cellular (33.94%), and biological pathways (19.6%). The cluster analysis indicated the formation of four distinct clusters among selected sugarcane accessions, with maximum genetic distance observed among the varieties. We believe that these EST-SSR markers will serve as valuable references for future genetic characterization, species identification, and breeding efforts in sugarcane. [ABSTRACT FROM AUTHOR]

Grapes are one of the most common agricultural crops in the world. Currently, the analysis of genotypes directly at the DNA level is considered to be the most accurate method for studying the plant gene pool. The study of wild vines and ancient varieties in various regions of viticulture is an important direction of research in this field. The purpose of this work was to study the population of wild grapes growing on the territory of the Utrish Nature Reserve on the Black Sea coast of Krasnodar Region. The territory of the reserve is of interest as it is a site of ancient settlements, and the environmental conditions are suitable for the growth of wild grapes. During the survey of the territory, 24 samples of wild grapes were found, which were described according to the main morphological characteristics and analyzed by the molecular genetic method. The found vines were genotyped using 15 DNA markers, including nine commonly used for DNA fingerprinting (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32, VrZAG62, VrZAG79) and VVIb23, which allows determining hermaphrodite and dioecious vines. Statistical processing of microsatellite loci polymorphism data was carried out using the GenAlEx 6.5 program. The genetic relationships of the studied vines were evaluated using the PAST 2.17c program. The samples were found to be morphologically and genetically polymorphic. The number of alleles identified in the sample varied from 5 to 18 and averaged 8 alleles per locus. Statistical processing of DNA analysis data made it possible to identify two genetically different populations among the wild discovered vines. An assessment of genetic similarity of the found vines with some local varieties of geographically close viticulture regions, rootstocks and representatives of Vitis sylvestris from other territories was made. One of the populations found in the Utrish Nature Reserve is close to a number of V. sylvestris genotypes, the DNA profiles of which are presented in the Vitis International Variety Catalogue.

The chloroplast (cp) genome holds immense potential for a variety of applications including species identification, phylogenetic analysis, and evolutionary studies. In this study, we utilized Illumina NovaSeq 6000 to sequence the DNA of Camellia sinensis L. cultivar 'Zhuyeqi', followed by the assembly of its chloroplast genome using SPAdes v3.10.1, with subsequent analysis of its features and phylogenetic placement. The results showed that the cp genome of 'Zhuyeqi' was 157,072 bp, with a large single-copy region (LSC, 86,628 bp), a small single-copy region (SSC,18,282 bp), and two inverted repeat regions (IR, 26,081 bp). The total AT and GC contents of the cp genome of 'Zhuyeqi' were observed to be 62.21% and 37.29%, respectively. The cp genome encoded 135 unique genes, including 90 protein-coding genes (CDS), 37 tRNA genes, and 8 rRNA genes. Moreover, 31 codons and 247 simple sequence repeats (SSRs) were identified. The cp genomes of 'Zhuyeqi' were found to be relatively conserved, with conservation observed in the IR region, which showed no evidence of inversions or rearrangements. The five regions with the largest variations were identified, with four regions (rps12, rps19, rps16, and rpl33) located in the LSC region and one divergent region (trnI-GAU) in the IR region. Phylogenetic analysis revealed that Camellia sinensis (KJ996106.1) was closely related to 'Zhuyeqi', indicating a close phylogenetic relationship between these two species. These findings could provide important genetic information for further research into breeding of tea tree, phylogeny, and evolution of Camellia sinensis. [ABSTRACT FROM AUTHOR]

On the basis of molecular-genetic approaches, the study of the biodiversity of the phytopathogenic fungus Pyricularia oryzae Cav. in the south of Russia and the classification of the morphological and culture characteristics of the pathogen is carried out. Between 2020 and 2022 monitoring was carried out and 24 strains of the pathogen were isolated from the affected herbarium material collected from the fields of five ecological rice growing zones of Krasnodar krai (Krasnoarmeisky, Kalininsky, Abinsky, Slavyansky districts, Krasnodar). Using the multiplex PCR system developed by us based on fragment analysis, five genotypes are identified among the studied Pyricularia oryzae Cav. strains over the entire period of the project, each of which is characterized by a unique genetic profile. Their DNA passports are compiled. The studied isolates of the causative agent of blast are characterized by morphological and culture characteristics. Six morphotypes of the pathogen are identified. [ABSTRACT FROM AUTHOR]

Background: Astragali Radix is regarded as an important traditional medicinal plant and has been widely used as a Qi-Invigoratin medicine for more than 2000 years. However, the mechanism of its medicinal and nutritional components in different accessions is unexplored. Moreover, the lack of SSR markers for Astragali Radix has stalled genetic breeding and variety identification. To develop EST-SSRs, transcriptome sequencing was performed based on the Illumina platform. Results: Approximately 99.6 million raw data points were collected, and 296,618 unigenes with an average length of 1,459 bp were obtained. A total of 71,207 SSR loci within 56,097 SSR-containing unigenes were identified. Of these SSR-containing unigenes, 26,188 (46.7%), 16,736 (29.8%), and 8,858 (15.8%) were related to items in the GO database, KEGG database, and COG database, respectively. The motifs A/T, AG/CT, AT/AT, and AAT/ATT were the most common types, accounting for 39.78%, 19.14%, 10.12%, and 4.60%, respectively, and the average length of the EST-SSRs was 17.16 bp. We acquired 8 functional markers linked to key genes correlated with the biosynthesis of flavonoids. The genetic similarity among the 60 AR varietal resources ranged from 0.2692 to 0.8077, with an average of 0.5742. The dendrogram results indicated that the 60 AR samples tested had high levels of genetic similarity. Conclusions: The 71,207 EST-SSR loci identified here offer valuable source of DNA markers for the genetic diversity identification of 60 Astragali Radix varieties. These results will facilitate genetic map construction, functional gene identification, variety identification, molecular marker-assisted breeding, and genetic diversity analysis in Astragali Radix. [ABSTRACT FROM AUTHOR]

Although morphological plasticity has been widely known in various cactus genera, few studies have investigated the origin and molecular relationship between morphological variants from cacti. Morphological variants are relevant specimens because atypical, exotic and generally unique forms are preferred by cactus traders and collectors. The current study investigates the molecular relationship between the tortuosus and monstruosus ornamental variants of Cereus peruvianus used in landscapes. Polymorphisms in loci of simple-sequence repeats in DNA were used as molecular markers. The variants tortuosus and monstruosus , and plants with typically columnar and erect shoots cultivated in southern Brazil were retrieved from public parks and home gardens. High polymorphism, an indicative of vegetative propagation, and a moderate genetic divergence were detected at the molecular level in monstruosus and tortuosus plants. Artificial selection and vegetative propagation of the ornamental variants of Cereus may be inducing a moderate genetic divergence and formation of two heterologous groups with conservative genetic diversity. Polymorphism in Cereus variants revealed groups with contrasting genes among the variants tortuosus and monstruosus which may be useful for breeding to generate new and different new variants. [ABSTRACT FROM AUTHOR]

Prunus sibirica (Siberian apricot) has ecological, economic, and social benefits that makes it an important fruit-bearing tree in China. However, current fruit yields are low and unstable, thus restricting development of Prunus sibirica industry. To provide a scientific basis for successful breeding research aimed at developing superior cultivars, 98 screened SSR markers were first used in our study, developed by restriction-site associated DNA sequencing, to assess the genetic diversity of 66 Prunus sibirica accessions collected from four populations. The average number of alleles per locus (9.910) and the number of effective alleles (5.445) showed high polymorphism in the entire population, and the polymorphism information content (0.675) indicated that these markers were highly polymorphic. There was gene flow among the Prunus sibirica accessions, however the genetic differentiation coefficient showed 15.4% gene frequency differentiation among the provenances. Meanwhile, extensive linkage disequilibrium (D′ > 0.5, P < 0.01) was found, however the overall level was low (r2 < 0.5, p < 0.01). Additionally, the 66 accessions clustered into four groups, and these groups were extremely significantly correlated with the provenances classification. The clustering results showed that geographical distribution and genetic diversity changed from high to low as the geographic separation between provenances increased. Furthermore, population structure analysis supported these findings as genetic structure and provenances were extremely significantly correlated (p < 0.01). Additionally, the relationships between the geographical and genetic distances of the provenances and of the individuals were significantly correlated, indicating that geographical isolation importantly influenced Prunus sibirica evolution. The geographic and genetic effects underlying the superior accessions which we selected provide a reference for future molecular marker assisted breeding of Prunus sibirica. [ABSTRACT FROM AUTHOR]

Copyright of NaUKMA Research Papers. Biology & Ecology is the property of National University of Kyiv-Mohyla Academy, Faculty of Humanities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Three polymorphic microsatellite loci were isolated and employed to examine paternity patterns in two natural populations of live-bearing mosquito fish, Gambusia holbrooki. Each locus displayed four to five alleles per population in samples of presumably unrelated adults. Nearly 900 embryos from a total of 50 pregnant females were assayed individually, and paternal alleles in each embryo were identified. Counts of paternal alleles, Mendelian segregation patterns, multilocus allelic associations and genetic relatedness coefficients were employed to estimate the minimum and effective numbers of fathers per brood. At least 90% of the assayed broods were shown to have been fathered by multiple males, a figure substantially higher than previous estimates based on less polymorphic genetic loci. However, the genetic data yield a face-value estimate of only about 2.2 fathers per brood, a number that seems perhaps surprisingly low based on frequencies of attempted copulations by males. Both biological and sampling factors that might bias mean sire counts downward are considered. Although higher sire counts per brood might be obtained from loci with even greater numbers of alleles, little statistical room remains for higher frequency estimates of multiple paternity in Gambusia.

Ten microsatellite markers were developed using next-generation sequencing data for Alibertia edulis (Rubiaceae), a widely distributed species typical of Cerrado (Brazilian savanna) vegetation. The markers were polymorphic in the two populations analyzed. The numbers of alleles, and observed (HO) and expected (HE) heterozygosities per polymorphic locus ranged from 2 to 11, 0.091 to 1.0, and 0.100 to 0.937 respectively. The SSR loci demonstrated moderate to high polymorphism values in both populations analyzed, with PIC values ranging from 0.26 to 0.91, and total allele numbers ranging from three to 16. The inbreeding coefficient values were generally higher in the Piauí population (ranging from − 0.593 to 0.762) than in the Mato Grosso population (ranging from − 1 to 0.575). The differences observed between those disjunct populations suggest they harbor different alleles, which has implications for Cerrado conservation strategies. Those loci will be useful for population studies of A. edulis. [ABSTRACT FROM AUTHOR]

Orchids have minute, air-filled seeds and are considered to be efficient dispersers and colonizers. However, empirical studies show that most seeds fall within a metre of the mother plant in orchids, and that individuals standing close to each other are often closely related. A poor contribution to gene dispersal by seeds may be compensated for by more efficient dispersal by pollen, but in autogamous or agamospermous orchids this component is not available. Here, we used two highly variable simple sequence repeat loci to analyse fine-scale genetic structure in the agamospermous orchid Nigritella miniata, which is widespread in alpine grasslands in the Dolomites. We studied a densely populated area of 30 × 50 m and an enlarged area of 100 × 500 m with more scattered occurences. Sp statistics, describing the decrease in relatedness with geographical distance, were 0.1073 and 0.0609, respectively, and were among the highest values recorded for the orchid family, revealing a strong genetic structuring. However, some genotypes in the studied area were distributed at distances up to 26.5 km in the Dolomites, which suggests that long-distance seed dispersal occurs occasionally and that populations separated by long distances can still be parts of the same meta-population system. [ABSTRACT FROM AUTHOR]

Sugarcane ( Saccharum spp. hybrids) is a worldwide acclaimed important agricultural crop used primarily for sugar production and biofuel. Sugarcane's genetic complexity, aneuploidy, and extreme heterozygosity make it a challenging crop in developing improved varieties. The molecular breeding programs promise to develop nutritionally improved varieties for both direct consumption and commercial application. Therefore, to address these challenges, the development of simple sequence repeats (SSRs) has been proven to be a powerful molecular tool in sugarcane. This study involved the collection of 285216 expressed sequence tags (ESTs) from sugarcane, resulting in 23666 unigenes, including 4547 contigs. Our analysis identified 4120 unigenes containing a total of 4960 SSRs, with the most abundant repeat types being monomeric (44.33%), dimeric (13.10%), and trimeric (39.68%). We further chose 173 primers to analyze the banding pattern in 10 sugarcane accessions by PAGE analysis. Additionally, functional annotation analysis showed that 71.07%, 53.6%, and 10.3% unigenes were annotated by Uniport, GO, and KEGG, respectively. GO annotations and KEGG pathways were distributed across three functional categories: molecular (46.46%), cellular (33.94%), and biological pathways (19.6%). The cluster analysis indicated the formation of four distinct clusters among selected sugarcane accessions, with maximum genetic distance observed among the varieties. We believe that these EST-SSR markers will serve as valuable references for future genetic characterization, species identification, and breeding efforts in sugarcane., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jiang, Waseem, Wang, Basharat, Zhang, Li and Liu.)

In this study, 28,691 genome sequences and 16,566 expressed sequence tags (ESTs) of Eucalyptus were derived from the GenBank database. A total of 2292 SSR loci were sought out from 1785 effective sequences. Through analyses of SSR loci information, the SSR motif length was negatively correlated with the abundance of the SSRs. In the EST sequences of Eucalyptus, triplet repeat motifs were the most abundant, and dinucleotide repeats motifs had the highest frequencies. Subsequently, 395 pairs of primers were designed based on the SSR loci. Using optimized SSR-PCR conditions, 340 pairs of primers were successfully screened, with a success rate of 86.1%. By construction of a maximum likelihood phylogenetic tree of six eucalypt species, represented by five species of the genus Eucalyptus and one of the genus Corymbia, the genetic relationships of Eucalyptus urophylla and E. camaldulensis suggested by this tree was found to differ from that suggested by traditional morphological taxonomy. The results provide insights for evaluating genetic diversity of Eucalyptus and analysis of Eucalyptus phylogenetics using SSR markers. [ABSTRACT FROM AUTHOR]

The distinction among Conyza canadensis, C. bonariensis, and C. sumatrensis is a challenge for weed science. In the current study, primers for microsatellite (SSR) loci were used to investigate the molecular divergence among the three species, the genetic structure of the populations at the molecular level and the level of genetic admixture among Conyza plants from southern Brazil. Twelve primers amplified well-defined DNA segments for all 88 samples of the three Conyza species. The estimated proportion of SSR polymorphic loci, number of alleles, and mean expected heterozygosity were higher in samples of C. bonariensis than in samples of C. sumatrensis or C. canadensis. Conyza canadensis was the species with the lowest molecular diversity. High genetic divergence was observed among the three species. The well-defined ancestral groups for each species led to the identification of samples of Conyza with ancestral genomes from the three species. Hybridization events between pairs of these species may have occurred in crop fields from southern Brazil. The high molecular diversity in resistant biotypes of C. sumatrensis indicated that these biotypes have a high potential to colonize new areas, which increases its potential as a weed. [ABSTRACT FROM AUTHOR]

Grapes are one of the most common agricultural crops in the world. Currently, the analysis of genotypes directly at the DNA level is considered to be the most accurate method for studying the plant gene pool. The study of wild vines and ancient varieties in various regions of viticulture is an important direction of research in this field. The purpose of this work was to study the population of wild grapes growing on the territory of the Utrish Nature Reserve on the Black Sea coast of Krasnodar Region. The territory of the reserve is of interest as it is a site of ancient settlements, and the environmental conditions are suitable for the growth of wild grapes. During the survey of the territory, 24 samples of wild grapes were found, which were described according to the main morphological characteristics and analyzed by the molecular genetic method. The found vines were genotyped using 15 DNA markers, including nine commonly used for DNA fingerprinting (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32, VrZAG62, VrZAG79) and VVIb23, which allows determining hermaphrodite and dioecious vines. Statistical processing of microsatellite loci polymorphism data was carried out using the GenAlEx 6.5 program. The genetic relationships of the studied vines were evaluated using the PAST 2.17c program. The samples were found to be morphologically and genetically polymorphic. The number of alleles identified in the sample varied from 5 to 18 and averaged 8 alleles per locus. Statistical processing of DNA analysis data made it possible to identify two genetically different populations among the wild discovered vines. An assessment of genetic similarity of the found vines with some local varieties of geographically close viticulture regions, rootstocks and representatives of Vitis sylvestris from other territories was made. One of the populations found in the Utrish Nature Reserve is close to a number of V. sylvestris genotypes, the DNA profiles of which are presented in the Vitis International Variety Catalogue., Competing Interests: The authors declare no conflict of interest., (Copyright © AUTHORS.)

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microsatellite transferability was used as a method to differentiate samples of mandacaru cultivated in the South (S), Southeast (SE), Northeast (NE) and Midwest (MW) regions of Brazil. Ten microsatellite primers designed from Polaskia chichipe (Pchi5, Pchi21, Pchi44 and Pchi47), Ariocarpus bravoanus (mAbR05, mAbR28 and mAbR86), Astrophytum asterias (AaB6 and AaD9), and Echinocactus grusonii (mEgR78) were polymorphic. A total of 31 alleles, which makes an average of 2.58 alleles per locus, were detected in mandacaru plants. The analyzed mandacaru cacti from the NE region presented lower polymorphism than their relatives from S, SE, and MW regions. The AMOVA showed a higher genetic variation among than within the analyzed samples. Clustering of the samples determined via Bayesian analysis indicated that the 112 analyzed mandacaru plants were grouped into 3 subpopulations. The highest proportion of plants from the S/SE (80.3%/77.5%), NE (91.5%), and MW (95%) were observed within blue, red, and green groups respectively: the mandacaru cacti form genetically structured populations. Molecular divergence at the SSR loci indicated three species: one species located in the South (S) and Southeast (SE) regions, another species in the Northeast (NE) region, and a third one in the Midwest (MW) region of Brazil. [ABSTRACT FROM AUTHOR]

The olive tree is one of the most common fruit species cultivated for oil and table olives in Italy and, particularly, in the Mediterranean area. DNA fingerprinting methods include different markers; however, our work is based on the identification of olive oil cultivars by using simple sequence repeats analysis. As previously reported in the literature, this proposed method shows good capability to amplify, for example, DNA from wine and table grape varieties. In our paper, we suggest an easy methodology, which allows direct amplification of DNA and bypassing of the extraction of DNA using an engineered DNA polymerase, KAPA3G Plant DNA polymerase, improved to tolerate plant PCR inhibitors. This new procedure is more efficient, faster and cheaper than traditional methods of DNA extraction and amplification and leads to more accurate results. This innovative protocol, without the addition of chemical solutions, has provided good results and has permitted traceability of virgin olive oils. [ABSTRACT FROM AUTHOR]

Key message: SSR marker characterization of Indian mango cultivars revealed two distinct groups of populations with geographical affiliation. Six SSR loci with low PI have been identified as universal markers for mango characterization. Abstract: In this study, genetic diversity and population structure of mango cultivars were assessed by employing fourteen simple sequence repeat markers, with high polymorphic information content. A set of 387 mango accessions from different regions of India was used. Model-based structure analysis revealed the presence of two subpopulations comprising the cultivars from 'South-West' region and 'North-East' region. A similar clustering pattern was observed in the dendrogram analysis, with two major groups identified that were further sub-grouped based on their genetic relatedness. Analysis of molecular variance showed a significant variance component among and within mango sub-populations derived from the structure analysis. The proportion of genetic differentiation among individuals within the two populations was found to be significant with a F value of 0.248. The extent of genetic diversity was found to be higher in case of 'South and West' population than 'North and East' population. Six SSR loci with low probability of identity values have been chosen as universal markers for mango characterization. Our results highlight genetic diversity encompassed by mango cultivars and genetic distinctness of 'South-West' and 'North-East' region cultivars. [ABSTRACT FROM AUTHOR]

Microsatellite transferability was used as a method to examine the genetic diversity and structure of populations in Pilosocereus gounellei seedling samples that have potential to implement effective restoration strategies for degraded and disturbed areas of the Caatinga biome. Genomic DNA was extracted from 85 seedlings obtained from fruit collected from plants growing in native areas in the Brazilian states of Piaui (PI), Rio Grande do Norte (RN), and Bahia (BA). Six microsatellite primers were polymorphic. AMOVA showed higher genetic variation within (72%) than among (28%) the samples from the three states. The high level of similarity between the seedlings from PI, BA, and RN indicated that samples collected at any of the three sites can be used to represent the genetic diversity of the species. Seeds of plants from the three States are recommended as samples for germplasm banks and/or the production of plantlets to i ) plant in areas of strategic reserves for forage, ii ) deploy new cultivation areas, iii ) restore degraded areas in the semi-arid Northeast, and iv ) maintain ecological reserve banks and fodder with genetically divergent plants. [ABSTRACT FROM AUTHOR]

Using next-generation sequencing, we developed the first whole-genome resources for two hybridizing Nothofagus species of the Patagonian forests that crucially lack genomic data, despite their ecological and industrial value. A de novo assembly strategy combining base quality control and optimization of the putative chloroplast gene map yielded ~32 000 contigs from 43% of the reads produced. With 12.5% of assembled reads, we covered ~96% of the chloroplast genome and ~70% of the mitochondrial gene content, providing functional and structural annotations for 112 and 52 genes, respectively. Functional annotation was possible on 15% of the contigs, with ~1750 potentially novel nuclear genes identified for Nothofagus species. We estimated that the new resources (13.41 Mb in total) included ~4000 gene regions representing ~6.5% of the expected genic partition of the genome, the remaining contigs potentially being nongenic DNA. A high-quality single nucleotide polymorphisms resource was developed by comparing various filtering methods, and preliminary results indicate a strong conservation of cp DNA genomes in contrast to numerous exclusive nuclear polymorphisms in both species. Finally, we characterized 2274 potential simple sequence repeat ( SSR) loci, designed primers for 769 of them and validated nine of 29 loci in 42 individuals per species. Nothofagus obliqua had more alleles (4.89) on average than N. nervosa (2.89), 8 SSRs were efficient to discriminate species, and three were successfully transferred in three other Nothofagus species. These resources will greatly help for future inferences of demographic, adaptive and hybridizing events in Nothofagus species, and for conserving and managing natural populations. [ABSTRACT FROM AUTHOR]

In present study we have made an attempt to trace possible lines in the evolution of A. bonaccordensis separating from A. hohenackeri , where translocations at the chromosomal level could have resulted in a shift of the habitat during evolution of A. bonaccordensis. This species is occurring as an endemic taxon at a higher altitude than it may have been the case with its ancestor that occupied lower altitudes and possibly a broader ecological niche. Morphological and physiological differences between the recent two closely related taxa, in spadix and appendix characters, corm flesh colour, pollen morphology and oxalate content, may be attributed also to the translocation at the cytological level. Detailed karyotype studies have been done in these Amorphophallus species from Southern Western Ghats, where they are critically endangered in their habitats, indicating that the chromosome number in both species is 2 n = 26. In both of them there is a considerable variation in the karyotype symmetry. Accordingly, A. hohenackeri is placed under 2B whereas A. bonaccordensis fits well to 3B category of Stebbins’ classification. The highly endemic species Amorphophallus bonaccordensis , known only from the type locality, is supposed to have originated from A. hohenackeri via many cycles of translocations resulting in heteromorphic, nearly telocentric chromosomes, peculiar satellites, and many mitotic abnormalities like bridges, laggards, micronuclei and heteromorpic bivalents, terminalised chiasmata, supernumerary chromosomes and multinucleate cells at meiosis. ISSR analysis with 17 ISSR primers revealed a higher number of unique bands in A. bonaccordensis . Also the ISSR data, when correlated with the karyotype data, indicate that A. bonaccordensis has probably originated from A. hohenackeri due to chromosomal rearrangements and high mutation of the SSR loci. [ABSTRACT FROM AUTHOR]

With 5 tables Abstract Maize breeders in Brazil developed the popcorn cultivar BRS Angela after eight cycles of recurrent selection using the composite CMS-43. We extracted the genomic DNA from the leaves of the BRS Angela, and we used 20 microsatellite markers to assess both the genetic distance and variability of this variety along the eight cycles (C0, CI, CII, CIII, CIV, CV, CVIA and CVIB) of the composite CMS-43. Sixty-nine alleles were detected in the popcorn cultivar BRS Angela with an average of 3.45 alleles per polymorphic locus. There was significant effect (P ≤ 0.01) only for D allele at the Umc 2343 locus and for the alleles A and B at the Umc 2226 locus. There was no tendency in the changes in the allele frequencies, presumably, because of selection for grain yield and popping expansion. The observed heterozygosity along these cycles ranged from 38.67% (CIII) to 26.67% (CVIB). These values indicate the presence of heterozygosity in the breeding cycles, and therefore, the 'BRS Angela' can participate in new cycles of recurrent selection. [ABSTRACT FROM AUTHOR]

Abstract: Using nine microsatellite loci, we studied the effects of selective logging on genetic diversity, mating system and pollen dispersal in a population of the tree species Hymenaea courbaril, located in a 546ha plot in the Tapajós National Forest, Pará State, Brazil. We analyzed 250 offspring (nursery reared seedlings) collected after a logging episode from 14 open-pollinated seed trees. These were compared to 367 seedlings from 20 open-pollinated seed trees previously collected from the pre-logging primary forest. The genetic diversity was significantly lower in the post-logging seed cohort. In contrast to the pre-logging population, significant levels of selfing were detected in the post-logging population (tm =0.962, P <0.05). However, correlated matings were reduced and the effective number of pollen donors almost doubled after harvesting (3.8 against 7.2). Logging also reduced pollen immigration into the plot (from 55% to 38%) and we found no significant correlation between the size of the pollen donors and the number of seeds fathered. Inside the plot, pollen dispersal distance was shorter before logging than after (827 and 952m, respectively) and the reproductive pollination neighbor area (A ep) was larger (average of 178ha). The individual and average variance effective population size within families (ranged from 1.80 to 3.21, average of 2.47) was lower than expected in panmictic populations (Ne =4). The results indicate that while logging greatly reduced the levels of genetic diversity after logging, it also increased genetic recombination within the population and constrained crossing among related individuals. The results show that low-density tropical tree species such as H. courbaril, when harvested in moderate levels may be resilient to a reduction in the reproductive population and may maintain similar levels of outcrossing and pollen dispersal after logging. [Copyright &y& Elsevier]

Cultivated groundnut ( Arachis hypogaea L.) is an agronomically and economically important oilseed crop grown extensively throughout the semi-arid tropics of Asia, Africa and Latin America. Rust ( Puccinia arachidis) and late leaf spot (LLS, Phaseoisariopsis personata) are among the major diseases causing significant yield loss in groundnut. The development of varieties with high levels of resistance has been constrained by adaptation of disease isolates to resistance sources and incomplete resistance in resistant sources. Despite the wide range of morphological diversity observed in the cultivated groundnut gene pool, molecular marker analyses have thus far been unable to detect a parallel level of genetic diversity. However, the recent development of simple sequence repeat (SSR) markers presents new opportunities for molecular diversity analysis of cultivate groundnut. The current study was conducted to identify diverse disease resistant germplasm for the development of mapping populations and for their introduction into breeding programs. Twenty-three SSRs were screened across 22 groundnut genotypes with differing levels of resistance to rust and LLS. Overall, 135 alleles across 23 loci were observed in the 22 genotypes screened. Twelve of the 23 SSRs (52%) showed a high level of polymorphism, with PIC values ≥0.5. This is the first report detecting such high levels of genetic polymorphism in cultivated groundnut. Multi-dimensional scaling and cluster analyses revealed three well-separated groups of genotypes. Locus by locus AMOVA and Kruskal–Wallis one-way ANOVA identified candidate SSR loci that may be valuable for mapping rust and LLS resistance. The molecular diversity analysis presented here provides valuable information for groundnut breeders designing strategies for incorporating and pyramiding rust and late leaf spot resistances and for molecular biologists wishing to create recombinant inbred line populations to map these traits. [ABSTRACT FROM AUTHOR]

The southern Pacific Ocean, off the New Zealand coast, has been reported as one sympatric area of the two parasite species Anisakis pegreffii and A. berlandi. Here, a multilocus genotyping approach, based on a panel of eleven DNA microsatellite (SSR) loci plus the sequences analysis of the nuclear nas10 nDNA and the mitochondrial mtDNA cox 2 gene loci, was applied to a total of N = 344 adults and larvae of Anisakis spp. from cetacean and fish species, respectively. Out of the newly scored SSR loci, Anisl 15 and Anisl 2 showed fixed alternative alleles between A. pegreffii and A. berlandi resulting as 100% diagnostic loci. Out of SSRs Anisl 00314 and Anisl 7 previously disclosed, two additional loci, i.e., Anisl 4 and Anisl 22, were found to be sex-linked. The Bayesian genotypes clustering approach (STRUCTURE) allowed identification, with a 100% of probability value, N = 208 specimens to the "pure parental" A. pegreffii , N = 133 to the "pure parental" A. berlandi , while one adult and two larval stages showed mixed ancestry between the two groups having, in all cases, a Q-value = 0.50. NEWHYBRIDS analysis assigned (100% of probability) those specimens to their F1 hybrid category. This represents the first evidence of contemporary hybridization between the two parasite species in a sympatric area. The pairwise F ST values estimated at intraspecific and interspecific level, inferred from both SSR loci and mitochondrial mtDNA cox 2 sequences, have also demonstrated the existence of two distinct panmictic units in this study area, corresponding respectively to A. pegreffii and A. berlandi. The results obtained support the useful application of a multilocus approach in the identification of sibling species and their hybrid categories in sympatric areas. The possible use of sex-linked SSR loci of the two species of the A. simplex (s. l.), for sex determination of their larval stages, is also suggested. • Multilocus genotyping in the genetic structure of A. pegreffii and A. berlandi. • Four SSR loci were newly scored in the two parasite species. • Anisl 2 and Anisl 15 are 100% diagnostic between the two species. • Two additional SSR loci were disclosed as sex-linked in the two species. • First evidence of contemporary hybridization between the two species. [ABSTRACT FROM AUTHOR]

Three polymorphic microsatellite loci were isolated and employed to examine paternity patterns in two natural populations of live-bearing mosquitofish, Gambusia holbrooki. Each locus displayed four to five alleles per population in samples of presumably unrelated adults. Nearly 900 embryos from a total of 50 pregnant females were assayed individually, and paternal alleles in each embryo were identified. Counts of paternal alleles, Mendelian segregation patterns, multilocus allelic associations and genetic relatedness coefficients were employed to estimate the minimum and effective numbers of fathers per brood. At least 90% of the assayed broods were shown to have been fathered by multiple males, a figure substantially higher than previous estimates based on less polymorphic genetic loci. However, the genetic data yield a face-value estimate of only about 2.2 fathers per brood, a number that seems perhaps surprisingly low based on frequencies of attempted copulations by males. Both biological and sampling factors that might bias mean sire counts downward are considered. Although higher sire counts per brood might be obtained from loci with even greater numbers of alleles, little statistical room remains for higher frequency estimates of multiple paternity in Gambusia. [ABSTRACT FROM AUTHOR]

* Premise of the study: A new set of 12 microsatellite markers was developed and characterized for big-leaf mahogany (Swietenia macrophylla King, Meliaceae) and its transferability assayed in the African mahogany, Khaya senegalensis (Desr.) A. Juss. (Meliaceae), to study population and conservation genetics of these threatened tropical timber species. * Methods and Results: Using an enriched library approach twelve novel microsatellite loci were identified for S. macrophylla. The number of alleles per locus ranged from 5 to 14 and mean observed and expected heterozygosities were 0.819 and 0.822, respectively. Twenty microsatellite loci developed for S. macrophylla (12 from this study and eight previously published) were tested for K. senegalensis and 10 polymorphic were characterized. * Conclusions: The results show the highly informative content of the new SSR loci for Swietenia macrophylla and the high effectiveness of these microsatellites for population genetics, gene flow, and mating system studies in Khaya senegalensis. [ABSTRACT FROM AUTHOR]