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Reliable estimates of population abundance and demographics are essential for managing harvested species. Ice‐associated phocids, "ice seals," are a vital resource for subsistence‐dependent coastal Native communities in western and northern Alaska, USA. In 2012, the Beringia distinct population segment of the bearded seal, Erignathus barbatus nauticus, was listed as "threatened" under the US Endangered Species Act requiring greater scrutiny for management assessments. We sought to estimate requisite population parameters from harvested seals by using close‐kin mark‐recapture (CKMR) methods, the first such application for marine mammals. Samples from 1758 bearded seals harvested by Bering, Chukchi, and Beaufort Sea communities during 1998–2020 were genotyped, genetically sexed, and aged by tooth annuli. After rigorous quality control, kin relationships were established for 1484 seals including two parent–offspring pairs (POPs) and 25 potential second‐order kin pairs. Most of the second‐order kin were half‐sibling pairs (HSPs), but four were potential grandparent‐grandchild pairs (GGPs). There were no full sibling pairs, suggesting a lack of mate fidelity. Mitochondrial DNA analysis identified 17 potential HSPs as paternally related, providing substantial evidence of persistent heterogeneity in reproductive success among adult males. The statistical CKMR model incorporates probabilities associated with POPs, HSPs, and GGPs and assumes known ages and a stable population. Our top model accommodates heterogeneity in adult male breeding success and yields an abundance estimate of ~409,000 with a coefficient of variation (CV) = 0.35, which is substantially greater than the "non‐heterogeneity" model estimate of ~232,000 (CV = 0.21), an important difference for managing a harvested species. Using CKMR methods with harvested species provides estimates of abundance with the added opportunity to acquire information about adult survival, fecundity, and breeding success that could be applied to other species of concern, marine and terrestrial. [ABSTRACT FROM AUTHOR]

Molecular markers are increasingly being deployed to accelerate genetic gain in crop plants. The objective of this study was to assess the potential of a mid-density genotyping panel for molecular applications in cowpea breeding. A core set of 2,602 targeted diversity array technology (DArTag) single-nucleotide polymorphisms (SNPs) was designed from an existing 51,128 Cowpea iSelect Consortium Array. The panel's usefulness was assessed using 376 genotypes from different populations of known genetic backgrounds. The panel was informative, with over 78% of SNPs exceeding a minor allele frequency of 0.20. The panel decoded three stratifications in the constituted population, as was expected. Linkage disequilibrium (LD) decay was correctly depicted as slower in a biparental subset than in other populations. A known flower and seed coat color gene region was located on chromosome Vu07, suggesting that the mid-density panel may be used to hypothesize genomic regions underlying target traits in cowpea. Unexpected heterozygosity was detected in some lines and highly among F1 progenies, divulging the panel's potential application in germplasm purity and hybridity verification. The study unveils the potential of an excellent genomic resource that can be tapped to enhance the development of improved cowpea cultivars. [ABSTRACT FROM AUTHOR]

Canola varieties exhibit variation in drought avoidance and drought escape traits, reflecting adaptation to water‐deficit environments. Our understanding of underlying genes and their interaction across environments in improving crop productivity is limited. A doubled haploid population was analysed to identify quantitative trait loci (QTL) associated with water‐use efficiency (WUE) related traits. High WUE in the vegetative phase was associated with low seed yield. Based on the resequenced parental genome data, we developed sequence‐capture‐based markers and validated their linkage with carbon isotope discrimination (Δ13C) in an F2 population. RNA sequencing was performed to determine the expression of candidate genes underlying Δ13C QTL. QTL contributing to main and QTL × environment interaction effects for Δ13C and yield were identified. One multiple‐trait QTL for Δ13C, days to flower, plant height, and seed yield was identified on chromosome A09. Interestingly, this QTL region overlapped with a homoeologous exchange (HE) event, suggesting its association with the multiple traits. Transcriptome analysis revealed 121 significantly differentially expressed genes underlying Δ13C QTL on A09 and C09, including in HE regions. Sorting out the negative relationship between vegetative WUE and seed yield is a priority. Genetic and genomic resources and knowledge so developed could improve canola WUE and yield. Summary Statement: Growing concerns about reduced water availability and climate change are putting pressure on sustainable food production worldwide. Identification of varieties, suitable for cultivation under reduced water inputs is critical to developing resilience to drought conditions. We identified 29 genetic and environmental determinants underlying plasticity in water use efficiency (WUE) and productivity traits. We show that one of the quantitative trait loci underlying variation in Δ13C, flowering time, plant height, and seed yield is subjected to homoeologous exchange and causes dosage‐dependent gene expression changes in WUE. Our results provide insights into the complexity of WUE genes and provide a strategy for improving canola adaptation under water‐deficit conditions. [ABSTRACT FROM AUTHOR]

With recent advances in sequencing technology, genomic data are changing how important conservation management decisions are made. Applications such as Close‐Kin Mark‐Recapture demand large amounts of data to estimate population size and structure, and their full potential can only be realised through ongoing improvements in genotyping strategies. Here we introduce DArTcap, a cost‐efficient method that combines DArTseq and sequence capture, and illustrate its use in a high resolution population analysis of Glyphis garricki, a rare, poorly known and threatened euryhaline shark. Clustering analyses and spatial distribution of kin pairs from four different regions across northern Australia and one in Papua New Guinea, representing its entire known range, revealed that each region hosts at least one distinct population. Further structuring is likely within Van Diemen Gulf, the region that included the most rivers sampled, suggesting additional population structuring would be found if other rivers were sampled. Coalescent analyses and spatially explicit modelling suggest that G. garricki experienced a recent range expansion during the opening of the Gulf of Carpentaria following the conclusion of the Last Glacial Maximum. The low migration rates between neighbouring populations of a species that is found only in restricted coastal and riverine habitats show the importance of managing each population separately, including careful monitoring of local and remote anthropogenic activities that may affect their environments. Overall we demonstrated how a carefully chosen SNP panel combined with DArTcap can provide highly accurate kinship inference and also support population structure and historical demography analyses, therefore maximising cost‐effectiveness. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pea (Pisum sativum) is one of the most important temperate grain legumes in the world, and its production is severely constrained by the pea aphid (Acyrthosiphon pisum). Wild relatives, such as P. fulvum, are valuable sources of allelic diversity to improve the genetic resistance of cultivated pea species against A. pisum attack. To unravel the genetic control underlying resistance to the pea aphid attack, a quantitative trait loci (QTL) analysis was performed using the previously developed high density integrated genetic linkage map originated from an intraspecific recombinant inbred line (RIL) population (P. fulvum: IFPI3260 × IFPI3251). RESULTS: We accurately evaluated specific resistance responses to pea aphid that allowed the identification, for the first time, of genomic regions that control plant damage and aphid reproduction. Eight QTLs associated with tolerance to pea aphid were identified in LGs I, II, III, IV and V, which individually explained from 17.0% to 51.2% of the phenotypic variation depending on the trait scored, and as a whole from 17.0% to 88.6%. The high density integrated genetic linkage map also allowed the identification of potential candidate genes co‐located with the QTLs identified. CONCLUSIONS: Our work shows how the survival of P. fulvum after the pea aphid attack depends on the triggering of a multi‐component protection strategy that implies a quantitative tolerance. The genomic regions associated with the tolerance responses of P. fulvum during A. pisum infestation have provided six potential candidate genes that could be useful in marker‐assisted selection (MAS) and genomic assisted breeding (GAB) after functional validation in the future. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Here we present "Restore and Renew," a replicable framework for gathering and interpreting evolutionary, ecological, and genomic data in support of restoration practices. In an era of rapid climatic change and continuous widespread clearing, revegetation projects need to focus on producing resilient and long‐term self‐sustaining populations. Restore and Renew expands current knowledge of genetic provenance via genome‐scan data, environmental niche modeling (ENM), and site‐specific climate information. The sampling strategy is to obtain leaf tissue representing the distributions of over 100 species commonly used in restoration. We apply generalized dissimilarity modeling to genome‐wide single nucleotide polymorphism datasets from hundreds of samples. Species‐specific local provenances are obtained using a model that represents observed patterns of genetic variation across the landscape. Climate modeling is implemented to interpret genetic provenance boundaries in the context of current and future climatic conditions at the specified site. Results are presented in an easy‐to‐use webtool (www.restore‐and‐renew.org.au), where the user simply selects their site of interest and a target species to obtain the size and distribution of local genetic provenance. Although Restore and Renew is not prescriptive, it allows restoration practitioners to make informed decisions on where to source material from, to fulfill their restoration scenario of choice. Two examples, Westringia fruticosa and Acacia suaveolens, are presented to demonstrate how the analytical pipeline responds to different ecological and evolutionary patterns. The webtool has multiple applications for biodiversity management and will continue to evolve with new species and analytical/interpretative outputs. [ABSTRACT FROM AUTHOR]

Understanding the evolutionary history of diversifying lineages and the delineation of evolutionarily significant units and species remains major challenges for evolutionary biology. Low‐cost representational sampling of the genome for single nucleotide polymorphisms shows great potential at the temporal scales that are typically the focus of species delimitation and phylogeography. We apply these markers to a case study of a freshwater turtle, Emydura macquarii, whose systematics has so far defied resolution, to bring to light a dynamic system of substantive allopatric lineages diverging on independent evolutionary trajectories, but held back in the process of speciation by low level and episodic exchange of alleles across drainage divides on various timescales. In the context of low‐level episodic gene flow, speciation is often reticulate, rather than a bifurcating process. We argue that species delimitation needs to take into account the pattern of ancestry and descent of diverging lineages in allopatry together with the recent and contemporary processes of dispersal and gene flow that retard and obscure that divergence. Underpinned by a strong focus on lineage diagnosability, this combined approach provides a means for addressing the challenges of incompletely isolated populations with uncommon, but recurrent gene flow in studies of species delimitation, a situation likely to be frequently encountered. Taxonomic decisions in cases of allopatry often require subjective judgements. Our strategy, which adds an additional level of objectivity before that subjectivity is applied, reduces the risk of taxonomic inflation that can accompany lineage approaches to species delimitation. [ABSTRACT FROM AUTHOR]

The capacity of the bread wheat ( Triticum aestivum) genome to tolerate introgression from related genomes can be exploited for wheat improvement. A resistance to powdery mildew expressed by a derivative of the cross-bread wheat cv. Tähti × T. militinae ( Tm) is known to be due to the incorporation of a Tm segment into the long arm of chromosome 4A. Here, a newly developed in silico method termed rearrangement identification and characterization ( RICh) has been applied to characterize the introgression. A virtual gene order, assembled using the GenomeZipper approach, was obtained for the native copy of chromosome 4A; it incorporated 570 4A DArTseq markers to produce a zipper comprising 2132 loci. A comparison between the native and introgressed forms of the 4 AL chromosome arm showed that the introgressed region is located at the distal part of the arm. The Tm segment, derived from chromosome 7G, harbours 131 homoeologs of the 357 genes present on the corresponding region of Chinese Spring 4 AL. The estimated number of Tm genes transferred along with the disease resistance gene was 169. Characterizing the introgression's position, gene content and internal gene order should not only facilitate gene isolation, but may also be informative with respect to chromatin structure and behaviour studies. [ABSTRACT FROM AUTHOR]

Determinacy is an agronomically important trait in several crop species including pigeonpea. With an objective to investigate determinacy in pigeonpea, a set of 94 pigeonpea lines including 11 determinate (DT) and 83 indeterminate (IDT) lines were used for genotyping with DArT arrays (with 6144 features) and 768 SNP markers using GoldenGate assay. The polymorphism information content (PIC) for these markers varied from 0.02 to 0.50. Association analysis on marker genotyping and phenotyping data showed a significant association (P ≤ 0.01) of determinacy with 19 SNP and 6 DArT markers explaining 8.05-8.58% and 7.26-14.53% phenotypic variation, respectively. Clustering based on entire DArT and SNP markers could not discriminate DT lines from IDT lines; however, analysis with associated markers discriminated DT lines from the IDT lines. Marker-trait associations after validation may prove useful in marker-assisted selection (MAS) involving the development of ideal DT genotypes for environments with moderate growth, tolerance to drought and water logging. This is the first report on mapping of determinacy trait as well as the first report on association mapping for any trait in pigeonpea. [ABSTRACT FROM AUTHOR]

We present the first results from a novel multiparent advanced generation inter-cross (MAGIC) population derived from four elite wheat cultivars. The large size of this MAGIC population (1579 progeny), its diverse genetic composition and high levels of recombination all contribute to its value as a genetic resource. Applications of this resource include interrogation of the wheat genome and the analysis of gene-trait association in agronomically important wheat phenotypes. Here, we report the utilization of a MAGIC population for the first time for linkage map construction. We have constructed a linkage map with 1162 DArT, single nucleotide polymorphism and simple sequence repeat markers distributed across all 21 chromosomes. We benchmark this map against a high-density DArT consensus map created by integrating more than 100 biparental populations. The linkage map forms the basis for further exploration of the genetic architecture within the population, including characterization of linkage disequilibrium, founder contribution and inclusion of an alien introgression into the genetic map. Finally, we demonstrate the application of the resource for quantitative trait loci mapping using the complex traits plant height and hectolitre weight as a proof of principle. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

A binary GAL4-VP16–UAS transactivation system has been established in rice ( Oryza sativa L.) in this study for the discovery of gene functions. This binary system consists of two types of transgenic lines, pattern lines and target lines. The pattern lines were produced by transformation of Zhonghua 11, a japonica cultivar, with a construct consisting of the transactivator gene GAL4- VP16 controlled by a minimal promoter and the GUSplus reporter controlled by the upstream activation sequence (UAS; cis-element to GAL4). Target lines were generated by transformation of Zhonghua 11 with constructs carrying the EGFP reporter and target genes of interest, both controlled by the UAS but in opposite directions. Hybrid plants were obtained by crossing target lines of 10 putative transcription factor genes from rice with six pattern lines showing expression in anther, stigma, palea, lemma and leaves. The EGFP and target genes perfectly co-expressed in hybrid plants with the same expression patterns as in the pattern lines. Various phenotypic changes, such as delayed flowering, multiple pistils, dwarfism, narrow and droopy leaves, reduced tillers, growth retardation and sterility, were induced as a result of the expression of the target genes. It is concluded that this transactivation system can provide a useful tool in rice to unveil latent functions of unknown or known genes. [ABSTRACT FROM AUTHOR]

Summary Plant chromosomes terminate in telomeres as in other eukaryotes. Telomeres are vital to genome stability and their malfunctioning is lethal. One of the core components of the telomere complex is telomerase. The enzyme activity depends on RNA (TER) and reverse transcriptase (TERT) subunits. We describe here the isolation, sequencing and characterization of the telomerase reverse transcriptase catalytic subunit from the monocot plant Oryza sativa L. (OsTERT ). A single copy of this gene is present in the rice genome. The protein predicted from the OsTERT sequence has all the signature motifs of the TERT family members. Our data indicate that rice telomerase activity is developmentally regulated and is high in in vitro tissue and cell culture. However, steady-state transcript levels of the TERT gene do not seem to correlate with enzyme activity. Northern and RT–PCR analyses of the OsTERT gene transcript profile show multiple differentially spliced transcripts in both telomerase-positive and telomerase-negative tissues. Based on quantitative analysis of these transcripts, we speculate that the overall balance between the quantities of particular alternatively spliced transcripts may determine whether the TERT protein(s) is active or not. The diversity of splicing variants detected suggests that, as recently discovered for mammalian TERT proteins, rice TERT protein variants may perform functions other than telomere maintenance. [ABSTRACT FROM AUTHOR]

Summary Enhancer trapping has provided a powerful strategy for identifying novel genes and regulatory elements. In this study, we adopted an enhancer trap system, consisting of the GAL4/VP16–UAS elements with GUS as the reporter, to generate a trapping population of rice. Currently, 31 443 independent transformants were obtained from two cultivars using Agrobacterium -mediated T-DNA insertion. PCR tests and DNA blot hybridization showed that about 94% of the transformants contained T-DNA insertions. The transformants carried, on average, two copies of the T-DNA, and 42% of the transformants had single-copy insertions. Histochemical assays of approximately 1000 T0 plants revealed various patterns of the reporter gene expression, including expression in only one tissue, and simultaneously in two or more tissues. The expression pattern of the reporter gene in T1 families corresponded well with the T0 plants and segregated in a 3 : 1 Mendelian ratio in majority of the T1 families tested. The frequency of reporter gene expression in the enhancer trap lines was much higher than that in gene trap lines reported previously. Analysis of flanking sequences of T-DNA insertion sites from about 200 transformants showed that almost all the sequences had homology with the sequences in the rice genome databases. Morphologically conspicuous mutations were observed in about 7.5% of the 2679 T1 families that were field-tested, and segregation in more than one-third of the families fit the 3 : 1 ratio. It was concluded that GAL4/VP16–UAS elements provided a useful system for enhancer trap in rice. [ABSTRACT FROM AUTHOR]