Search Results (186)

The role of rhizosphere bacteria in facilitating plant invasion is increasingly acknowledged, yet the influence of specific microbial functional traits remains insufficiently understood. This study addresses this gap by isolating two bacterial strains, Bacillus sp. ScRB44 and Pseudomonas sp. ScRB22, from the rhizosphere of the invasive weed Solidago canadensis. We assessed their nitrogen utilization capacity and indoleacetic acid (IAA) production capabilities to evaluate their ecological functions. Our three-stage experimental design encompassed strain promotion, nutrient stress, and competition phases. Bacillus sp. ScRB44 demonstrated robust IAA production and significantly improved the nitrogen utilization efficiency, significantly enhancing S. canadensis growth, especially under nutrient-poor conditions, and promoting a shift in biomass allocation toward the roots, thereby conferring a competitive advantage over native species. Conversely, Pseudomonas sp. ScRB22 exhibited limited functional activity and a negligible impact on plant performance. These findings underscore that the ecological impact of rhizosphere bacteria on invasive weeds is closely linked to their specific growth-promoting functions. By enhancing stress adaptation and optimizing resource allocation, certain microorganisms may facilitate the establishment of invasive weeds in adverse environments. This study highlights the significance of microbial functional traits in invasion ecology and suggests novel approaches for microbiome-based invasive weed management, with potential applications in agricultural soil health improvement and ecological restoration. Full article

This study aimed to evaluate the forage yield, quality, and weed suppression potential of narbon vetch (Vicia narbonensis L.) and Italian ryegrass (Lolium multiflorum L.) grown as sole crops and in mixtures under organic farming conditions in Bilecik, Turkey, during the 2020–2021 growing season. The experiment included 15 treatments comprising monocultures and mixed sowing at different ratios. Measurements included morphological traits, forage yield components (green herbage, hay, and crude protein), fiber content, botanical composition, and weed biomass. The results reveal significant differences among treatments in terms of growth parameters and forage performance. Monocultures of IFVN 567 and Bartigra showed the highest green and hay yields, while mixtures such as IFVN 567 + Trinova and IFVN 567 + Bartigra outperformed in terms of land equivalent ratio (LER) and protein yield, demonstrating a clear advantage in land use efficiency. Furthermore, these mixtures showed superior weed suppression compared to monocultures. Overall, the findings suggest that carefully selected vetch–ryegrass combinations can enhance forage productivity, nutritional quality, and weed management under organic systems. Full article

The wild tomato (Solanum sisymbriifolium) is a globally distributed shrubby weed with both negative and positive impacts, including its invasive properties and the potential for pharmaceutical and traditional medicinal uses. Despite its ecological significance, the plant’s reproductive biology and pollination ecology remain poorly understood. This study aimed to investigate the floral biology, pollination ecology, and plant reproduction of the weed species. Some flower traits, such as flowering intensity, flower display size, and pollen and ovule production, peaked during spring, summer, and the monsoon, while flower longevity and stigmatic receptivity were the longest in winter. The plant species was self-compatible (ISI = 0.02), heavily depended on pollinators (IDP = 0.72), and experienced minimal pollination limitation (D = 0.10) under open-pollination conditions. Flower visitors’ traits (e.g., abundance, diversity, and richness) were higher in the spring, summer, and the monsoon, and these were lower in winter. The vital pollination service was provided by Amegilla zonata, Ceratina binghami, Lasioglossum cavernifrons, Nomia (Curvinomia) strigata, Tetragonula pagdeni, Xylocopa aestuans, Xylocopa amethystina, Xylocopa fenestrata, and Xylocopa latipes. Reproductive success, as indicated by fruit and seed set, varied seasonally, being higher during the spring–monsoon period and lower in winter. These findings support effective management of this weed species and help conserve the associated bee populations. Full article

Diseases and weeds occupy a leading place among the factors limiting the yield of agricultural crops, including rice. These factors can be overcome through the use of chemical protective agents, as well as through the creation and introduction into agricultural production of rice varieties resistant to these stressors. The use of DNA marking technologies for target genes of economically valuable traits in the creation of promising varieties allows not only for the identification of genes but also the monitoring of their transmission during crosses and the selection of breeding-valuable genotypes with genes of interest. In addition, this ensures a reduction in the volume of breeding nurseries, as well as time and material costs during variety modeling, and rapid rotation of new high-yield varieties with specified characteristics. We have selected effective marker systems based on the use of DNA marking technologies for target genes for resistance to blast (Pi) and submergence tolerance (Sub1A). These systems allow for precise targeted selection of hybrid plants with these genes in the breeding process. In addition, we have automated the detection of transferred Pi-ta and Pi-b genes, which greatly relieves the DNA analysis during mass screening of breeding material. The final result of this work is the created rice varieties Al’yans, Lenaris and Kapitan with the Pi-ta blast resistance gene and the Pirouette rice variety with the Pi-1, Pi-2, and Pi-33 genes. These varieties exceed the standards by 0.64–2.2 t/ha, and their involvement in production makes it possible to obtain additional products by increasing yields in the amount of about RUB 80 thousand/ha. Full article

Barnyard grass is the most problematic weed in paddy fields in Ningxia. Its substantial morphological variation complicates both identification and control, yet the genetic diversity of barnyard grass infesting paddy fields in Ningxia has not been thoroughly studied. In this research, we analyzed the genetic diversity of 46 barnyard grass populations from Ningxia’s paddy fields based on the assessment of morphological traits, DNA barcoding, and SCoT-targeted gene markers. Nine morphological traits were quantitatively analyzed, among which three phenological traits, i.e., leaf length, stem diameter, and plant height, exhibited notable variations. Correlational analysis revealed a positive relationship between morphological traits and multi-herbicide resistance profiles. To assess genetic diversity, four DNA barcodes (ITS, psbA, matK, and trnL-F) were used, among which ITS demonstrated the strongest potential in single-gene barcoding for barnyard grass species identification. Cluster analysis based on ITS barcode sequences was performed to group the populations into five main categories. Additionally, SCoT marker analysis using six primers was performed to classify the 46 barnyard grass samples into five groups. The results showed that the predominant barnyard grass species in Ningxia were E. colona, E. crus-galli var. Formosensis, E. crusgalli, E. oryzoides, and E. crusgalli var. Zelayensis, with E. colona being the most prevalent. The differences observed between the morphological and molecular marker-based classifications were method-dependent. However, both SCoT molecular marker technology and DNA barcoding contributed to identifying the genetic diversity of barnyard grass. Taken together, our study revealed significant morphological and genetic variations among barnyard grass populations, which correlated with herbicide sensitivity in Ningxia’s paddy fields, underscoring the necessity for an integrated weed management approach to combat this troublesome weed species. Full article

Meeting the rising demand for staple grains now requires cultivars that combine high yield, enhanced nutritional value, and strong chemical resilience. Blue-kernel landraces from central Mexico are rich in anthocyanins yet remain highly susceptible to post-emergence herbicides, whereas modern hybrids detoxify these compounds through cytochrome P450 (CYP450) enzymes. We crossed the anthocyanin-rich variety Polimaize with a CYP450-tolerant hybrid and evaluated the two parents and their F₁ segregants (designated “White” and “Yellow”) under greenhouse applications of mesotrione (75 g a.i. ha⁻¹), nicosulfuron (30 g a.i. ha⁻¹), and their mixture. Across 160 plants, the hybrid retained 95% of control dry matter and showed ≤7% foliar injury under all treatments, whereas Polimaize lost 28% biomass and exhibited 36% injury after nicosulfuron. The Yellow class matched hybrid performance while maintaining a blue pericarp and a β-carotene-rich endosperm, demonstrating that nutritional and agronomic traits can be stacked. The White class displayed heterosis-driven compensatory growth, exceeding its untreated biomass by 60% with nicosulfuron and by 82% with the mixture despite transient bleaching. Chlorophyll and carotenoid fluorescence revealed rapid, zeaxanthin-linked photoprotection in all tolerant genotypes, consistent with accelerated CYP450-mediated detoxification. These findings show that broad-spectrum herbicide tolerance can be introgressed into pigment-rich germplasm through conventional breeding, providing a non-transgenic path to herbicide-ready, anthocyanin-rich maize. The strategy preserves local biodiversity while delivering cultivars suited to intensive, weed-competitive agriculture and offers a template for integrating metabolic resilience into other native crops. Full article

Background: Weed herbicide resistance is a serious problem in crop protection globally. Giant foxtail (Setaria faberi R.A.N. Herrm.) populations cannot be controlled by acetolactate synthase (ALS)-inhibiting herbicides in a few corn (Zea mays L.) monoculture fields. Methods: Five putative resistant giant foxtail populations, originating from corn monoculture fields in northeastern Greece, were evaluated for possible evolution of ALS-inhibitor resistance (nicosulfuron, rimsulfuron). The resistance ratio, the underlying resistance mechanism, and its impact on competitive ability against corn were studied. Results: The whole-plant rate-response assays showed that these populations were resistant (R) to the sulfonylureas nicosulfuron and rimsulfuron, but susceptible (S) to imidazolinone imazamox, triketone 4-hydroxyphenylpyruvate dioxygenase inhibitor tembotrione, and acetyl-CoA carboxylase inhibitor cycloxydim. The sequencing of the ALS gene did not reveal the presence of resistance-associated point mutations, indicating that the resistance was probably not target-site mediated. This was confirmed by the application of piperonyl butoxide two hours before nicosulfuron application, which reversed the resistance in all R giant foxtail populations, supporting the evidence of enhanced metabolism-mediated resistance. The competition study between corn and R or S giant foxtail populations indicated no stable trend reduction in corn traits, suggesting that the resistance mechanism was not associated with the competitive ability of the R populations. The novel ALS genotype in S. faberi, characterized for the first time and submitted to the GenBank database with accession number PV016837, indicated a closer genetic relationship with the S. viridis ALS gene than with S. italica. Conclusions: Five giant foxtail populations have evolved metabolism-based resistance to the ALS-inhibiting herbicides nicosulfuron and rimsulfuron. Full article

The continued emergence of weedy rice (Oryza sativa L.) in Taiwan poses serious challenges to seed purity and commercial rice cultivation, particularly under transplanting systems. These off-type individuals, often marked by a red pericarp, reduce varietal integrity and complicate seed propagation. This study evaluated the morphological variation among 117 Taiwan weedy rice (TWR) accessions and 55 control cultivars, which include 24 temperate japonica cultivars (TEJ), 24 indica cultivars, and seven U.S. weedy rice (UWR) types. Principal component analysis (PCA) showed that TWR shares vegetative traits with modern cultivars but exhibits grain morphology resembling indica landraces—indicating weak artificial selection pressure on grain traits during nursery propagation. TWR was also found to possess a suite of adaptive weedy traits, including semi-dwarfism, delayed heading, high shattering, and superior seed storability, facilitating its persistence in field conditions. These findings provide critical insights for integrated weed management and cultivar purity strategies, emphasizing the importance of certified seed use, stringent field hygiene, and disruption of weedy rice reproductive cycles. Full article

The direct-seeded rice (DSR) system is poised to become the dominant rice cultivation method due to its advantages, including reduced water usage, less labor requirements, decreased greenhouse gas emissions, and improved adaptation to climate change. However, weeds, particularly jungle rice (Echinochloa colona), significantly hinder DSR and cause substantial yield losses. This study aimed to develop rice cultivars competitive against jungle rice through selective breeding, focusing on early seed germination (ESG) and seedling vigor (ESV). We utilized 181 early-backcross selective introgression breeding lines (EB-SILs) developed using Green Super Rice (GSR) technology by backcrossing Weed Tolerant Rice1 (WTR1) with three donor parents, Haoannong, Cheng Hui 448, and Y134. Using the tunable genotyping-by-sequencing (tGBS^®, Data2Bio Technologies, Ames, IA, USA) method, we identified 3971 common single nucleotide polymorphisms (SNPs) that facilitated the mapping of 19 novel quantitative trait loci (QTLs) associated with weed competitiveness—eight linked to ESG traits and eleven to ESV traits. Notably, all QTLs were novel except qRPH1, linked to relative plant height at 14 and 21 days after sowing. Key QTLs were located on chromosomes 2, 3, 5, 6, 8, 9, 10, and 12. Candidate genes identified within these QTLs are implicated in the plant’s response to various abiotic and biotic stresses. Our findings enhance the understanding of the genetic basis for ESG and ESV traits critical for weed competitiveness, supporting marker-assisted and genomic selection approaches for breeding improved rice varieties. Furthermore, this research lays the groundwork for employing gene expression, cloning, and CRISPR editing strategies to combat jungle rice, with potential applications for other weed species and contributing to effective integrated weed management in the DSR system. Full article

Apera spica-venti is a weed that is threatening agricultural crops worldwide. Current reports do not fully agree on the biology of the weed, regarding the viability of diaspores, nor is there sufficient information on how different factors affect the germination of its seeds, such as the abundance of soil where the mother plant (plants from which diaspores (caryopsis) were collected) has grown or the effect of biostimulants on their germination. Therefore, the main aim of this study was to compare the germination of newly harvested seeds of A. spica-venti (3 months after harvest) with seeds that had been stored for 1, 2, 3, 4, or 5 years. Furthermore, the influence of seed age, weed location, and biostimulants (silicon and algal liquids) on the germination of A. spica-venti diaspores was checked. Three-year-old seeds showed the highest percentage of germination, and their germination process was positively correlated with soil abundance (from sites of mother plant material collection) and macronutrients (N, P, K). The strongest correlations were recorded for 3- and 4-year-old seeds. A. spica-venti seeds treated with biostimulant preparations were characterized by varying percentages of germination. No clear trend was noted regarding the germination capacity of the harvested seeds as the diaspores aged, and it depended on the type of stimulant and the place of origin of the seed. Moreover, seeds from the harvest year treated with the stimulant were characterized by a higher germination percentage. A. spica-venti is a highly fecund weed, a trait that makes it very common in crops, appearing en masse and providing formidable competition to crops, thus causing significant yield losses. Awareness of the vitality of diaspores will allow for the possible regulation and control of this weed in order to prevent yield loss in crops. The theme of diaspore viability warrants further investigation. Further research should include observations of factors affecting germination, including new stimulants emerging on the agricultural market. Full article

Plant growth analysis provides insight regarding the variation behind yield differences in tested genotypes for plant breeders, but adopting this application solely for traditional plant phenotyping remains challenging. Here, we propose a procedure of using uncrewed aerial systems (UAS) to obtain successive phenotype data for growth analysis. The objectives of this study were to obtain high-temporal UAS-based phenotype data for growth analysis and investigate the correlation between the UAS-based phenotype and biomass yield. Seven different energy cane genotypes were grown in a random complete block design with four replications. Twenty-six UAS flight missions were flown throughout the growing season, and canopy cover (CC) and canopy height (CH) measurements were extracted. A five-parameter logistic (5PL) function was fitted through these temporal measurements of CC and CH. The first- and second-order derivatives of this function were calculated to obtain several growth parameters, which were then used to assess the growth of different genotypes with respect to weed competitiveness and biomass yield traits. The results show that CC and CH growth rates significantly differed among genotypes. TH16-16 was outstanding for its ground cover growth; therefore, it was identified as a weed-competitive genotype. Furthermore, TH16-22 had a higher CH maximum growth rate per day, yielding a higher biomass compared to other genotypes. The CH-based multi-temporal data as well as the growth parameters had a better relationship with biomass yield. This study highlights the application of UAS-based high-throughput phenotyping (HTP), along with growth analysis, for assisting plant breeders in decision-making. Full article

Insect pests and weeds are the two major biotic factors affecting crop yield in the modern agricultural system. In this study, a brown planthopper (BPH) resistance gene (BPH9) and glufosinate tolerance gene (bar) were stacked into a single T-DNA cassette and transformed into an indica rice (Oryza sativa L.) line H23. The present study employed a gene stacking process that combines more than one gene/trait into an individual transgenic plant to meet the increasing cropping demands under complex conditions. The transgenic rice H23 (H23R) co-expressing bar and BPH9 genes demonstrated both glufosinate tolerance and BPH resistance. We utilized transcriptome data to reveal the mechanism of BPH9-mediated brown planthopper resistance and to analyze the impact of exogenous transgenic fragments on upstream and downstream genes at insertion sites. The evaluation of insect resistance and glufosinate tolerance confirmed H23R as an excellent double-resistant transgenic rice. These findings indicate that H23R can satisfy insect management and weed control in the modern rice agricultural system. However, a deregulation study will help with prospective commercial planting. Full article

Mangrove ecosystems are globally significant for their biodiversity and ecosystem services but face persistent threats from invasive species and anthropogenic disturbances. This study investigates the interactions between Cyperus rotundus, a widespread invasive weed, and fungal communities in the mangrove-adjacent wetlands of Isla Santay, Ecuador. Using metagenomic sequencing of the ITS region, we analyzed fungal diversity in samples from an anthropogenically pressured area and a non-impacted site. Results revealed significant differences in microbial assemblages: the rhizosphere sample from the disturbed area exhibited lower fungal richness and was dominated by Magnaporthaceae (9%) and Aureobasidium melanogenum (5%), both associated with stress-tolerant traits. In contrast, the rhizosphere sample from the non-impacted site showed higher species diversity, with Cladosporium dominicanum (62%) and Talaromyces (11%) as dominant endophytic taxa. Principal Coordinates Analysis (PCoA) and co-occurrence networks highlighted distinct fungal partitioning between the two sample tissues, indicating that C. rotundus mediates microbial composition in response to environmental gradients. These findings underscore the role of microbial communities in the plant’s invasive success and suggest that leveraging beneficial fungi could enhance ecosystem resilience and support wetland restoration. By integrating molecular approaches with ecological insights, this work contributes to a deeper understanding of microbial dynamics in coastal wetlands and informs targeted management strategies to preserve mangrove habitats. Full article

The mung bean (Vigna radiata (Linn) Wilczek.) is a major grain crop in China, but its yield is significantly impacted by weeds. However, no pre-emergence herbicides are registered for mung bean fields in the China Pesticide Information Network. Screening for efficient and safe pre-emergence herbicides could improve mung bean production efficiency. In this study, six pre-emergence herbicides were selected: 480 g/L alachlor (1935.00 g a.i ha⁻¹), 720 g/L metolachlor (1620.00 g a.i ha⁻¹), 100 g/L imazethapyr (100.50 g a.i ha⁻¹), 338 g/L oxadiazon (507.00 g a.i ha⁻¹), 330 g/L pendimethalin (144.00 g a.i ha⁻¹), and 480 g/L trifluralin (720.00 g a.i ha⁻¹). Through Petri dish screening, a spraying treatment was carried out before seed germination. By measuring the root length and shoot length, imazethapyr (100.50 g a.i ha⁻¹) and oxadiazon (507.00 g a.i ha⁻¹) were screened out. They were applied to potted plants and sprayed after sowing. The results showed that imazethapyr (100.50 g a.i. ha⁻¹) and oxadiazon (507.00 g a.i. ha⁻¹) had no inhibitory effect on the growth and development of the mung bean. Subsequently, experiments were conducted with imazethapyr (100.50 g a.i ha⁻¹) and oxadiazon (507.00 g a.i ha⁻¹) applied in the field. Compared to the control, under imazethapyr (100.50 g a.i ha⁻¹) and oxadiazon (507.00 g a.i ha⁻¹), the agronomic traits, photosynthetic pigment content, yield, and yield components were not inhibited; the activities of superoxide dismutase, peroxidase, and catalase were increased; and gas exchange and chlorophyll fluorescence were not inhibited. In addition, soil urease activity decreased and soil invertase and alkaline phosphatase activity increased after 60 d of treatment. In summary, imazethapyr and oxadiazon can effectively control weeds and increase mung bean yield. The purpose of this study is to screen out safe and efficient pre-emergence herbicides suitable for the Shanxi mung bean, which is of great significance due to its large-scale planting industrialization and the development of advantageous industries. Full article

Recurrent selection for early vigour traits in wheat (Triticum aestivum L.) has provided an opportunity to generate competitive biotypes to suppress agronomically important weeds. Quantifying the potential benefits of competitive genotypes, including yield improvement and reduced frequency of herbicide application when incorporated into a long-term rotation, is vital to increase grower adoption. In this simple economic model, we evaluated a weed-suppressive early vigour genotype utilising on-farm experimental results and simulation analysis to predict gross margins for a seven-year wheat-canola rotation in southeastern Australia. The model applied a local weather sequence and predicted wheat production potential, costs and benefits over time. An early vigour wheat genotype was compared to commercial wheat cultivars for weed control, yield and actual production cost. With respect to weed control, three scenarios were evaluated in the model: standard herbicide use with a commercial cultivar (A), herbicide use reduced moderately by inclusion of an early vigour wheat genotype and elimination of the postharvest grass herbicide (B) or inclusion of an early vigour wheat genotype and withdrawal of both postharvest grass and broadleaf herbicides (C). Cost savings for the use of a competitive wheat genotype ranged from 12 AUD/ha in scenario B to 40 AUD/ha in scenario C, for a total saving of 52 AUD/ha. The model generated annual background gross margins, which varied from 300 AUD/ha to 1400 AUD/ha based on historical weather conditions, production costs and crop prices over the 30-year period from 1992 to 2021. The benefits of lower costs for each of the three scenarios are presented with rolling seven-year average wheat–canola rotation gross margins over the 30-year period. The limitations of this model for evaluation of weed suppression and cost benefits are discussed, as well as relative opportunities for adoption of early vigour traits in wheat. Full article