No‐analogue futures are characteristic of the Anthropocene, but how global change, and societies' responses, will affect plant invasions remains unclear. Conducting research now to address future needs is crucial for guiding invasion management and policy. We used four previously developed non‐exclusive scenarios to forecast trajectories of plant invasions into natural areas by 2050 and identify research gaps and future management needs. Scenarios explored positive and perverse consequences of aspirational biodiversity policies (Indigenous land tenure, native reforestation, non‐native mammal removal) and increasing extreme weather through climate change. The scenarios are set in Aotearoa New Zealand, which is on the forefront of emerging conservation issues and faces significant impacts from invasive plants. Under each scenario we considered socio‐economic and ecological drivers such as changes in land use and biotic interactions, focussing on public and private conservation areas. For a scenario considering increased land ownership or stewardship by Indigenous people, sociological research around bicultural communication was key to meet expected management needs. Under increased native reforestation, research into the impacts of landscape connectivity and long‐term resilience of restoration plantings was highlighted. With non‐native mammalian predator eradication, identifying the impact of species' removal from ecological networks and plant traits that promote success will be essential to identify emerging invaders. Increases in extreme weather events will disrupt management and spread ruderal invaders, requiring the development of better decision‐making and prioritization tools. Several priorities emerged across all scenarios, including the need for research and data advances, better management tools, and improved communication and consensus‐building. Investment in these areas provides long‐term benefits across a range of possible futures. Our approach, using invasion drivers, filters and traits to forecast the impact of future scenarios covering multiple global drivers of environmental change, can be widely applied to identify gaps, drive research agendas and proactively anticipate management and policy needs.

We outline the diversity of pests, weeds and plant pathogens absent from New Zealand that threaten forage production, examine their potential import pathways, and outline the challenges of managing them should they arrive. The number and diversity of threats and pathways indicates ongoing incursions are inevitable. Thus, we also review measures in place for detecting and responding to forage biosecurity threats when they arrive and find almost none, which contrasts with measures in place for protecting other crops. Alarmingly, therefore, New Zealand's least protected plants include ryegrass and white clover which are vastly more valuable than any of its other better protected crops. We contend that forage productivity and farm profitability are suffering death by a thousand cuts as each new incursion adds to forage plants’ pest burdens. There are clear opportunities to reduce rates of establishment of new pests, weeds and pathogens, and limit the damages they will cause post‐establishment. Critical needs include comprehensive pest risk analyses to inform risk mitigation, and surveillance targeting the most important threats. Forage‐based industries must recognize the biosecurity risks they face, collectively summon the will to act, and capitalize on opportunities for collaboration to minimize further erosion of forage productivity.

Alopecurus myosuroides Huds. (black-grass) has become problematic globally due to its repeated evolution of herbicide resistance. Three incursions via contaminated seed lots have occurred in the past 20 years despite strict border biosecurity in New Zealand. However, it is not known if the black-grass populations linked to these incursions carried herbicide resistance. Enough seed was obtained from contaminated seed lots (ryegrass-linked population UK2007; linseed-linked population FR2021) for a dose–response assay to test resistance to a commercial herbicide product containing both iodosulfuron and mesosulfuron, used for black-grass control in Europe, but not enough for repetition of the experiment or to test multiple herbicides. Seed lot FR2021 showed a high level of resistance, requiring 250g ai/ha to achieve 90% control (LD90) more than ten times the label rate whereas seed lot UK2007 had an LD90 of 19.0 g ai/ha almost twice the label rate (10 g ai/ha). Acetohydroxyacid synthase (AHAS)-inhibitor herbicides should not be used against black-grass populations during incursion responses in New Zealand. Any future black-grass incursions will be increasingly likely to carry herbicide resistance traits. Strong border measures, certified seed use, avoiding seed sourced from infested areas and screening for resistance are critical for prevention and effective control of black-grass incursions.

Global change and public participation are both areas of considerable uncertainty in estimating the success of biosecurity response strategies, but are poorly integrated in most available scenario analysis frameworks. We introduce INApest(), a novel network simulation method which integrates social and global change factors, as well as pest biology and multiple management variables in scenario analyses of biosecurity responses. INApest() separates the management response into four key parameters: probability of detection; management adoption; eradication of local populations; spread reduction (e.g. through movement restrictions or hygiene measures). It also permits simulation of biosecurity responses which evolve organically as new incidences of the pest are detected and information about the pest and management technologies spread through the network. We demonstrate selected functionality of INApest() using Nassella neesiana (Chilean Needle Grass; CNG), a slow-spreading pasture weed that impacts animal health, as a case-study. Realistic historical CNG spread rates are reproduced under a no management scenario using dispersal kernels derived from known natural and human-mediated spread mechanisms. Scenario analyses comparing over 15,000 parameter combinations reveal that communication of invasive threat to farms neighbouring known infestations significantly reduces the farm-scale eradication probability and spread reduction required for management success (i.e. success is achieved at lower levels of farm-scale management practice efficacy). We use targeted simulation experiments to show how INApest() permits assessment of cross-border consequences of local management decisions and how communication between landowners interacts with climate change and surveillance effort to impact management success. INApest() has the potential to be used at multiple scales and to explore a wide range of management, global change and social scenarios.

Nassella neesiana (Chilean needle grass) reduces farm profitability through its sharp seeds that damage wool, skins, hides and carcasses. It poses a biosecurity risk in New Zealand's Hawke's Bay region due to its seed dispersal via gravel and crushed aggregate from braided rivers. This study evaluated flotation and sieving to remove both dry and imbibed panicle seeds. We measured their length, width, mass, flotation, and passage through sieves with and without the awn (a hygroscopic, bristle-like structure). The dry awned seeds were, on average, 70.12 mm long and 1.13 mm wide, increasing to 74.07 mm long and 1.21 mm wide when imbibed. With imbibition, their mass with awn, increased from 9.41 to 14.06 mg, and from 3.96 to 5.04 mg with awn detached. Flotation was highest for the dry awned seeds (50%) and lowest for imbibed awned seeds (3%). The awn and imbibition restricted the seeds' passage through sieves while sand and a crushed aggregate (GAP 20 metal) facilitated their passage. The results indicate that flotation would be ineffective for removing N. neesiana seeds from river gravel but that an 8 mm aperture sieve could effectively remove them along with fine aggregate particles.

Glyphosate is the most frequently used herbicide in vineyards. Ryegrass (Lolium spp.) has developed resistance to glyphosate in vineyards across New Zealand. Recently, two vineyards in Marlborough were suspected to have glyphosate-resistant wild carrot (Daucus carota L.). Seeds from those vineyards, and two others without suspected resistance, were collected and tested with recommended rates of glyphosate (720 g ai ha-1), glufosinate-ammonium (1500 g ai ha-1) and amitrole (4000 g ai ha-1). Glyphosate did not kill wild carrot plants from the suspected resistant vineyards but glufosinate-ammonium and amitrole were effective. Wild carrot seedlings from a putative-resistant population (Renwick) and susceptible population (Riverlands) were treated again with glyphosate in dose-response assays. The other two populations had insufficient seed or poor germination and were excluded. Dose-response assays revealed that wild carrot plants from one of these vineyards (Renwick) were 2.91-6.64 times less sensitive to glyphosate (LD50 versus GR50) than plants from a susceptible population (Riverlands). The Renwick population exhibited 91% survival at the recommended rate of glyphosate (compared to 13% survival for Riverlands). Frequent usage of glyphosate in vineyards has been selected for resistance in wild carrot. This is the first study to document glyphosate resistance in wild carrot globally.

BACKGROUND AND AIMS:Genomic changes triggered by polyploidy, chromosomal rearrangements and/ or environmental stress are among factors that affect the activity of mobile elements, particularly long terminal repeat retrotransposons (LTR-RTs) and DNA transposons. Because these elements can proliferate and move throughout host genomes, altering the genetic, epigenetic and nucleotypic landscape, they have been recognized as a relevant evolutionary force. Beaksedges (Rhynchospora) stand out for their wide cosmopolitan distribution, high diversity (~400 species) and holocentric chromosomes related to high karyotypic diversity and a centromere-specific satDNA, Tyba. This makes the genus an interesting model to investigate the interactions between repetitive elements, phylogenetic relationships and ecological variables. METHODS:Here we used comparative phylogenetic methods to investigate the forces driving the evolution of the entire set of mobile elements (mobilome) in the holocentric genus Rhynchospora. We statistically tested the impact of phylogenetic relationships, abundance of holocentromeric satDNA Tyba, diversity of repeatome composition, ecological variables and chromosome number in mobile element diversification. KEY RESULTS:Tyba abundance was found to be inversely correlated with LTR-RT content. Decrease of LTR abundance and diversity was also related to increase in chromosome number (likely due to fission events) and colonization of dry environments in the northern hemisphere. In contrast, we found constant LTR insertions throughout time in species with lower chromosome numbers in rainier environments in South America. A multivariate model showed that different traits drive LTR abundance, especially repeat diversity and Tyba abundance. Other mobile elements, such as non-LTR RTs and DNA transposons, had insufficient abundance to be included in our models. CONCLUSIONS:Our findings suggest that LTR evolution is strongly impacted by the holocentric characteristics of Rhynchospora chromosomes, correlating with species diversification and biome shifts, and supporting a holokinetic drive model of evolution and a competitive scenario with Tyba. Altogether, our results present evidence of multi-trait influence on LTR-RT dynamics and provide a broader understanding of transposable element evolution in a macroevolutionary context.

The international crop seed trade is a major pathway for the unintentional introduction of non-native invasive plant species and herbicide-resistant weeds, posing biosecurity threats to agriculture and ecosystems. However, published studies examining weed contaminants in crop seed remain scarce. To address this, we analysed Canadian Food Inspection Agency (CFIA) monitoring data for 2,080 randomly sampled crop seed lots imported from the United States of America (USA) between 2007 and 2019. Both nations are major players in the global seed trade, making them key biosecurity case studies. We reported 262 contaminant species: 70% were introduced in Canada, 23% were native, and 7% had not been previously recorded (absent) in Canada. General weeds (not also imported as crops) comprised 63% of contaminant species; the remaining species were classified as seed of another crop. CFIA-classified noxious weeds (Classes 1–5) made up 12% of the contaminant species. Most contaminants were associated with only one or two crop species. There was a decline in general and noxious weeds, and noxious weeds were reported significantly less than non-noxious weeds over the study period. Entry-prohibited species (Class 1) were rare, limited to four records of Cuscuta spp. We identified 14 general weed species currently absent from Canada, notably the frequently reported Trifolium vesiculosum, along with Galium parisiense, Torilis nodosa, and Trifolium hirtum, all established in climatically similar regions of the USA, as well as Bromus catharticus and Euphorbia aleppica, identified as environmental and agricultural threats. Eight additional species, such as Apera spica-venti, currently limited to one Canadian province, pose a potential domestic spread risk. Reported Class 2 CFIA noxious weeds, including Cirsium arvense, Convolvulus arvensis, and Elymus repens, are of concern as their ecological range is not fully realised in Canada. Chenopodium album was the most widespread general weed detected across crop species. Contaminants with a known history of herbicide resistance in the USA but not in Canada increased significantly over time (e.g., Sorghum halepense, Poa annua), while those resistant in one Canadian province (Bromus tectorum) risk further spread in Canada. The introduction of new resistance is of concern when a contaminant species is reported in a crop type in Canada and documented as herbicide-resistant in the same crop type in the USA (Poa annua in forage and turf seed lots). Regulatory concerns include importing crops that are also classified as noxious or problematic weeds (Bromus tectorum, Poa annua), permitting contaminants absent from Canada in seed lots, and the dual classification of species that are native but also entry-prohibited (Cuscuta campestris). Our study highlights that expanded global seed trade necessitates ongoing seed lot monitoring, risk assessment, and adaptive regulations to help safeguard agriculture and biodiversity without hindering trade.

BACKGROUND:Conventional weed risk assessments (WRAs) are time-consuming and often constrained by species-specific attribute data gaps. We present a validated, algorithmic alternative, the CPG model, that integrates climatic suitability ( C ), weed-related publication frequency (P) and global occurrence data ( G ), using publicly available databases and artificial intelligence (AI)-assisted text screening with a large language model (LLM). RESULTS:The CPG model was tested against independent weed hazard classifications for New Zealand and California. In New Zealand, 89% of 480 randomly selected plant taxa had sufficient data to generate scores, which aligned well with expert classifications and moderately with outputs from the 48-question WRA [Pheloung PC, Williams PA, and Halloy SR. Journal of Environmental Management 57:239-251 (1999)]. For more than 5000 species assessed using Randall's 14-criteria generalised risk model [Randall RP, 20th Australasian Weeds Conference: 5-12 (2016)], all CPG variables were informative. The model also showed strong agreement with a 19-criteria California weed hazard system. Multinomial regression and receiver operator characteristic curve (ROC) analyses confirmed consistent predictive performance, with true-positive rates from 0.69 to 0.90 and true-negative rates from 0.71 to 0.97. It effectively distinguished high- from low-hazard species. Sensitivity analysis showed that as evidence for weediness increased, score stability improved, supporting robust rankings for high-hazard species. CONCLUSION:The CPG model offers a transparent, scalable and cost-effective tool for early-stage weed hazard screening. It delivers substantial time savings over attribute-based WRAs while maintaining alignment with expert evaluations. The model enables rapid triage of large species lists, including actual or potentially introduced taxa under current and future climates, supporting prioritisation for detailed risk or management feasibility assessments. Its automation and reproducibility make it a valuable tool for global biosecurity and invasive species management. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

We identified sleeper weeds: species that are already naturalised but remain limited in distribution and are likely capable of spreading into pastures in Northland, New Zealand. The species were significant agricultural weeds overseas, including subtropical species that could expand with climate change. We identified 33 potential sleeper weeds, comprising four grasses, twenty-two broadleaf herbs, one succulent herb, and six shrubs. The low forage quality grasses (Chloris gayana, Digitaria ciliaris, Melinis repens, Setaria sphacelata) are known to invade pastures. Six species toxic to livestock were identified. Three quarters of all the species are known problems in subtropical or tropical areas globally, so may be emerging problems under climate change. Regular incipient weed surveys and farmer reporting in both urban and agricultural areas are crucial, as these locations are often overlooked. Vigilance in detecting unusual plants, coupled with strict farm hygiene, remains the best strategy to prevent new weed spread.

BACKGROUND:Ryegrass (Lolium spp.) is a key forage providing a $14 billion contribution to New Zealand's gross domestic product (GDP). However, ryegrass can also act as a weed and evolve resistance to herbicides used for its control. Farmers suspected that imported seed might contribute to resistance issues. Herbicide resistance frequencies were investigated in commercial ryegrass seed lines intended for multiplication in New Zealand. Samples from 56 basic seed lots and 52 unique cultivars sourced from regions including New Zealand, United States, Europe and Japan were planted in field trials. Seedlings were then sprayed with three common herbicides: glyphosate, iodosulfuron, and haloxyfop. Surviving plants were retested to confirm resistance. RESULTS:Resistance to haloxyfop and or iodosulfuron was detected in 79% of seed lines. However, frequencies were not significantly higher in imported lines (from United States and Europe) compared with New Zealand lines. Resistance was detected at frequencies between 0.00112% and 10% for haloxyfop and between 0.00212% and 14.28% for iodosulfuron Resistance to glyphosate was not found. There was no significant difference between the resistance detected in seed samples sourced from different seed companies. CONCLUSIONS:It was found that 63% of resistant lines had resistance frequencies rarer than 0.1%, but this is potentially problematic considering typical sowing rates. Imported versus domestic seed sources were not significantly different; they pose similar levels of resistance risk to farmers. Lolium multiflorum had a higher resistance frequency compared to Lolium perenne (although only six L. multiflorum lots were evaluated). Breeders should screen progeny of early crosses for herbicide resistance. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Weeds are increasingly documented with evolved resistance to herbicides globally. Three species have been reported as resistant in maize crops in New Zealand: Chenopodium album to atrazine and dicamba, Persicaria maculosa to atrazine and Digitaria sanguinalis to nicosulfuron. Despite knowledge of these cases, the distribution of these resistant biotypes is unknown. This study aimed to determine the prevalence of known resistant weeds in major maize growing areas in New Zealand, and to pro-actively screen other species for resistance. Weed seeds of broadleaf and grass species were collected from 70 randomly selected maize growing farms in the North Island in 2021-2022. Seeds were grown and treated with herbicides at recommended field rates. Atrazine-resistant C. album were recorded in a third of surveyed farms and nicosulfuron-resistant D. sanguinalis in a sixth. Half of Waikato farms and a quarter of Bay of Plenty farms (no Hawkes Bay or Wellington farms) had atrazine-resistant C. album. Dicamba-resistant C. album were not detected, nor were atrazine-resistant P. maculosa. Nicosulfuron resistant D. sanguinalis was recorded in 19% of Waikato farms, 6% of Bay of Plenty farms and 9% of Hawkes Bay farms (no Wellington farms). Amaranthus spp., Fallopia convolvulus, Persicaria spp., Solanum spp., Echinochloa crus-galli, Panicum spp. and Setaria spp. were not resistant to any of the herbicides tested. Twenty-nine to 52% of maize farms in the North Island are estimated to have herbicide resistant weeds. Resistance is common in maize farms in Waikato and western Bay of Plenty. Resistance is rare in southern regions, with only one instance of nicosulfuron-resistant D. sanguinalis and no resistant C. album. Most annual weeds in maize are not resistant to herbicides; although atrazine resistant C. album is widespread, it is currently controlled with alternative herbicides. Resistant D. sanguinalis appears to be an emerging problem.

A government research grant and industry co-funding allowed us to briefly provide free tests of suspected cases of herbicide resistance using traditional seedling-based assays. Information about the service was disseminated through the Foundation for Arable Research and other weed management professionals. Between 2019 and 2022 we received 248 seed samples collected by rural professionals from individual plants suspected of resistance. We successfully tested 195 samples from eight species from 57 farms. Rural professionals were good at recognising cases of resistance; 77% of these seed samples from 40 farms (70%) had resistance confirmed. We gained insights into contextually unique cases of resistance previously undescribed in the literature in New Zealand, including ryegrass resistance to glyphosate in a barley crop, Poa annua resistance to iodosulfuron in wheat, and Phalaris minor resistance to iodosulfuron in wheat. Resistance was typically confirmed 6-8 weeks after planting seed samples, though for species with seed after-ripening requirements to ensure consistent germination, results took as long as 6 months. The results facilitated conversations about long-term resistance avoidance strategies. Future costs of an independent resistance testing service would ideally be shared by the stakeholders benefitting from the crop protection product value chain, from herbicide producers to land managers.

Background:Ripgut brome (Bromus diandrus Roth) is a problematic weed in New Zealand cereals and has developed resistance to various herbicides worldwide, including ACCase, ALS, and EPSPS inhibitors. A population in New Zealand's South Island from wheat recently showed resistance to the ALS-inhibitor pyroxsulam. This study investigates the resistance level in this population. Methods:The resistant ripgut brome population was compared to a susceptible population from a nearby organic farm. The level of resistance to pyroxsulam was determined using dose-response assays. The cytochrome P450 inhibitor malathion was used to evaluate the possible role of cytochrome P450 in herbicide metabolism. Results:The estimated LD50 for pyroxsulam in the resistant population was significantly higher (126 g ai ha(-1)), suggesting a 20-fold reduction in sensitivity compared to the control (6 g ai ha(-1)). Malathion pre-treatment increased herbicide sensitivity in susceptible and resistant populations. Conclusions:This study confirms significant resistance to pyroxsulam in a New Zealand ripgut brome population and suggests that a target-site resistance mechanism is the most likely explanation. This research adds to global evidence that ripgut brome can become resistant to pyroxsulam and underscores the escalating issue of herbicide-resistant weeds in New Zealand agriculture.

Resistance to iodosulfuron, a herbicide targeting acetolactate synthase (ALS), was identified and characterised in a population of Lolium perenne L. from Canterbury, New Zealand. The resistant population was 264 times more resistant to iodosulfuron than a susceptible population, based on a ratio of the rate corresponding to a 50% reduction in resistant and susceptible plant survival (R/S LD50). The resistant population was also 14-times more resistant to nicosulfuron, another ALS-inhibitor of the same class. However, no resistance to imazapyr, an ALS-inhibitor from a different chemical class, was detected in the resistant population. Pre-treatment with an inhibitor of cytochrome P450 reduced the level of iodosulfuron resistance to 46-fold in the resistant population, suggesting enhanced herbicide metabolism, a non-target site mechanism, contributed to resistance of this herbicide. In addition, a proline to leucine substitution at codon 197 was detected, suggesting a target-site-based mechanism was also associated with resistance to iodosulfuron. This is the first report on the resistance mechanisms to ALS-inhibiting herbicides identified in Lolium perenne in New Zealand and highlights the importance of integrated weed management approaches to reduce the likelihood of ALS-inhibitor herbicide resistance becoming more widespread.

Rapid identification of herbicide-resistant weeds plays a crucial role in their management. Glyphosate resistance in Lolium perenne is a growing issue in New Zealand and can be conferred by a single nucleotide polymorphism (SNP) causing amino acid substitutions at codon 106 in the 5-enolpyruvoylshikimate-3-phosphate synthase (EPSPS) gene. High-throughput molecular (HTM) methodologies that can detect such SNPs include high-resolution melting and real-time quantitative PCR probe assays. Here, we compare the effectiveness of both assays with a more labour-intense derived cleaved amplified polymorphic sequence (dCAPS) test for detecting SNPs at codon 106. The results showed that both HTM assays detected mutations at this codon, and their results were consistent with those of the dCAPS. Unlike dCAPS, however, the HTM assays over-estimated homozygosity for the glyphosate resistance allele. Nevertheless, cost-effective high-throughput detection of resistance is more important than the zygosity status when initiating an on-farm management response. In summary, both HTM assays successfully identified glyphosate resistance alleles at codon 106 in the EPSPS gene. Given that both assays are more cost-effective and can screen a larger number of samples in a timely manner compared to the dCAPS method, they can be used as quick tests for detecting glyphosate resistance in L. perenne.

BACKGROUND The setting and following of phytosanitary standards for weed seeds can lessen the impacts of weeds on agriculture. Standards adopted by seed companies, laboratories and regulators ensure the contamination rates do not exceed some thresholds. Globally sample size standards are set based on the amount needed to obtain a contaminant in a random sample of the seed lot, not detectability. New Zealand requires a 95% confidence that the maximum pest limit of 0.01% of quarantine weed seed contamination is not exceeded in an imported seed lot. We examined 24 samples each containing approximately 150 000 seeds of either perennial ryegrass (12 samples) or white clover seeds (12 samples) that were then spiked with seeds (contaminants) from 12 non-crop species (3-8 seeds of each). We considered factors that may impact detection rates: shape, color, size, and texture relative to the crop, and technician (including a commercial seed laboratory). RESULTS A linear mixed model fitted to the data indicated significant observer, crop, and seed color, shape, and size effects on detection. Detectability increased by 20% +/- 7.7 (+/- standard error) when seeds had a distinct shape or color (28% +/- 8.1), or were larger (23% +/- 8.7) rather than smaller, relative to the crop. Commercial laboratory identifications were usually correct at the level of genus, and species for common weeds, but some misidentifications occurred. CONCLUSION Sample sizes for border inspections should be based on detectability of regulated weed seeds in the crop in combination with weed risk for the crop and location. (c) 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Nassella neesiana (Chilean needle grass), an invasive 'sleeper weed' established in sheep and beef pastures in three of New Zealand's sixteen local government regions, has a potential geographic range amounting to 3.96 million hectares spanning all regions except the West Coast. It impacts the productivity, market value and welfare of livestock through its sharp penetrating that cause blindness and the downgrading of wool, hides, and carcasses. In this study we estimate the benefit of preventing its spread as the present value (PV) of local (regional) and national productivity losses that would accrue over 200 years under a 'do nothing' spread scenario. Using a 3% discount rate and two assumed spread rates, 201 and 100 years to 90% occupation of its potential range, we calculate national PV losses of NZ$ 192 million and NZ$ 1,160 million respectively. In a breakeven analysis, these losses, which equate to the national benefits of preventing the spread, justify annual expenditures of NZ$ 5.3 million and NZ$ 34 million respectively. Restricting the analyses to the regions with known infestations (Hawke's Bay, Marlborough, Canterbury) provided much lower estimates of the benefits (ranging from NZ$ 16.8 million to NZ$ 158 million) because spillover benefits from preventing spread to the other susceptible regions are not accounted for. These analyses support a nationally coordinated approach to managing N. neesiana in New Zealand involving surveillance and control measures respectively in the susceptible and infested regions.

Background and Aims Satellite DNAs (satDNAs) are repetitive sequences composed by tandemly arranged, often highly homogenized units called monomers. Although satDNAs are usually fast evolving, some satDNA families can be conserved across species separated by several millions of years, probably because of their functional roles in the genomes. Tyba was the first centromere-specific satDNA described for a holocentric organism, until now being characterized for only eight species of the genus Rhynchospora Vahl. (Cyperaceae). Here, we characterized Tyba across a broad sampling of the genus, analysing and comparing its evolutionary patterns with other satDNAs. Methods We characterized the structure and sequence evolution of satDNAs across a robust dadated phylogeny based on Hybrid Target-Capture Sequencing (hyb-seq) of 70 species. We mined the repetitive fraction for Tyba-like satellites to compare its features with other satDNAs and to construct a Tyba-based phylogeny for the genus. Key Results Our results show that Tyba is present in the majority of examined species of the genus, spanning four of the five major clades and maintaining intrafamily pairwise identity of 70.9% over 31 Myr. In comparison, other satellite families presented higher intrafamily pairwise identity but are phylogenetically restricted. Furthermore, Tyba sequences could be divided into 12 variants grouped into three different clade-specific subfamilies, showing evidence of traditional models of satDNA evolution, such as the concerted evolution and library models. Besides, a Tyba-based phylogeny showed high congruence with the hyb-seq topology. Our results show structural indications of a possible relationship of Tyba with nucleosomes, given its high curvature peaks over conserved regions and overall high bendability values compared with other non-centromeric satellites. Conclusions Overall, Tyba shows a remarkable sequence conservation and phylogenetic significance across the genus Rhynchospora, which suggests that functional roles might lead to long-term stability and conservation for satDNAs in the genome.

Pastures represent about half of the global agricultural area and productivity losses from weeds are significant. The complex interactions between them and other pasture plants, livestock and the environment imply a need for innovative research that transforms pasture management. To this end, a horizon scan was conducted to identify relevant issues, questions, opportunities, and drivers. The drivers were ranked using three criteria: (1) is this a horizon (is the driver likely to become important in 10-20 years?); (2) will the research require stretchy science (is it currently not well addressed by the science community?); (3) is the research transformative (will successful scientific research in this area lead to significant changes to weed management in pastures?). We identified 11 major issues and 46 subordinate ones. The three highest ranked major issues were: (1) anticipated reductions in access to herbicides; (2) rethinking weed management under an ecosystem services paradigm; (3) responding to shifts in best practice and the regulations that are altering farm system planning to reduce farming's environmental impacts. We conclude that fundamental interdisciplinary research is needed that addresses biosecurity and weed management issues, while reducing the environmental footprint of farming and maintaining productivity.