Sugarcane disease recognition through visible and near-infrared spectroscopy using deep learning assisted continuous wavelet transform-based spectrogram.

Utilizing visible and near-infrared (Vis-NIR) spectroscopy in conjunction with chemometrics methods has been widespread for identifying plant diseases. However, a key obstacle involves the extraction of relevant spectral characteristics. This study aimed to enhance sugarcane disease recognition by combining convolutional neural network (CNN) with continuous wavelet transform (CWT) spectrograms for spectral features extraction within the Vis-NIR spectra (380-1400 nm) to improve the accuracy of sugarcane diseases recognition. Using 130 sugarcane leaf samples, the obtained one-dimensional CWT coefficients from Vis-NIR spectra were transformed into two-dimensional spectrograms. Employing CNN, spectrogram features were extracted and incorporated into decision tree, K-nearest neighbour, partial least squares discriminant analysis, and random forest (RF) calibration models. The RF model, integrating spectrogram-derived features, demonstrated the best performance with an average precision of 0.9111, sensitivity of 0.9733, specificity of 0.9791, and accuracy of 0.9487. This study may offer a non-destructive, rapid, and accurate means to detect sugarcane diseases, enabling farmers to receive timely and actionable insights on the crops' health, thus minimizing crop loss and optimizing yields.

Improving Sphenophorus levis Adult Mortality Through Solid Insecticide Applications and Increased Insecticide Dose.

The sugarcane weevil (Sphenophorus levis Vaurie, 1978) is currently considered the most important sugarcane pest in Brazil, causing significant yield losses. Application methods of insecticides for S. levis control have not been effective, mostly due to the insect's cryptic behavior below the soil surface which suppresses the correct placement of insecticide active ingredients on target. Two experiments were conducted using an innovative bioassay methodology that simulates sugarcane field conditions to effectively evaluate S. levis adult mortality and insecticide residues in the soil under different treatments. The first experiment aimed to assess the efficacy of two liquid- and solid-applied insecticides, while the second aimed to examine the effect of increasing the dose of lambda-cyhalothrin + thiamethoxam on S. levis adult control. The novel bioassays simulated liquid and solid insecticide applications on sugarcane by exposing S. levis adults to chemical residuals on rhizomes and in soil after insecticide application. In the first experiment, low S. levis adult control was detected (< 53% mortality) across all treatments, where both solid and liquid applications of lambda-cyhalothrin + thiamethoxam provided greater efficacy levels than imidacloprid and control treatments, respectively. Solid applications maintained higher insecticide concentrations in the soil for longer periods than liquid insecticide applications, providing maximum insect control levels 7 days after application. The second experiment revealed that solid applications at higher insecticide doses significantly improved control of S. levis adult (76.7% mortality) and resulted in greater insecticide concentrations in the soil compared to the recommended label rate (58.8% mortality).

Sequencing vs. amplification for the estimation of allele dosages in sugarcane (Saccharum spp.).

Premise: Detecting single-nucleotide polymorphisms (SNPs) in a cost-effective way is fundamental in any plant breeding pipeline. Here, we compare three genotyping techniques for their ability to reproduce the allele dosage of SNPs of interest in sugarcane (Saccharum spp.). Methods: To identify a reproducible technique to estimate allele dosage for the validation of SNP markers, the correlation between Flex-Seq, kompetitive allele-specific PCR (KASP), and genotyping-by-sequencing and restriction site-associated DNA sequencing (GBS+RADseq) was determined for a set of 76 SNPs. To find alternative methodologies for allele dosage estimation, the KASP and Flex-Seq techniques were compared for the same set of SNPs. For the three techniques, a population of 53 genotypes from the diverse sugarcane panel of the Centro de Investigación de la Caña de Azúcar (Cenicaña), Colombia, was selected. Results: The average Pearson correlation coefficients between GBS+RADseq and Flex-Seq, GBS+RADseq and KASP, and Flex-Seq and KASP were 0.62 ± 0.27, 0.38 ± 0.27, and 0.38 ± 0.30, respectively. Discussion: Flex-Seq reproduced the allele dosages determined using GBS+RADseq with good levels of precision because of its depth of sequencing and ability to target specific positions in the genome. Additionally, Flex-Seq outperformed KASP by allowing the conversion of a higher number of SNPs and a more accurate estimation of the allele dosage. Flex-Seq has therefore become the genotyping methodology of choice for marker validation at Cenicaña.

Premisa: Detectar polimorfismos de un único nucleótido (SNP) de forma costo­efectiva es fundamental en cualquier programa de mejoramiento genético. En este artículo nosotros comparamos tres técnicas de genotipado para medir su habilidad en reproducir las dosis alélicas de SNPs de interés en caña de azúcar (Saccharum spp.). Métodos: Para identificar una técnica reproducible para la estimación de dosis alélicas durante los pasos de validación de marcadores, la correlación entre Flex­Seq, kompetitive allele­specific PCR (KASP), y genotyping­by­sequencing and restriction site­associated DNA sequencing (GBS+RADseq) fue determinada para un set de 76 SNPs. Para identificar metodologías alternativas en la estimación de las dosis alélicas, las tecnologías KASP y Flex­Seq fueron comparadas para el mismo grupo de SNPs. Para las tres técnicas, una población de 53 genotipos fue seleccionados de la población diversa de caña de azúcar del Centro de Investigación de la Caña de Azúcar (Cenicaña), Colombia. Resultados: El promedio del coeficiente de correlación de Pearson entre GBS+RADseq y Flex­Seq, GBS+RADseq y KASP, y Flex­Seq y KASP fue de 0.62 ± 0.27, 0.38 ± 0.27, y 0.38 ± 0.30, respectivamente. Discusión: Flex­Seq reprodujo las dosis alélicas determinadas usando GBS+RADseq con buenos niveles de precisión debido a su profundidad de secuenciación y habilidad de secuenciar posiciones especificas en el genoma. Adicionalmente, Flex­Seq superó a KASP al permitir la conversión de un número mayor de SNPs y al estimar las dosis alélicas de forma más precisa. Flex­Seq por tanto se convierte en la metodología de genotipado de elección para la validación de marcadores en Cenicaña.

"Efficient novel fungal-enriched biochar formulation for hexavalent chromium bioremediation".

Chromium (Cr), a key element in industrial processes such as leather tanning, poses severe environmental hazards, particularly its hexavalent form, Cr(VI), which is highly toxic and prevalent in tannery effluents/sludge. The persistence and toxicity of Cr(VI) necessitate the development of effective remediation strategies to mitigate its environmental impact. This study investigated the potential of Trichoderma yunnanense (NBRICRF_97) and its combination with 0.5% sugarcane bagasse biochar (SBC) for the reduction of Cr(VI). The results demonstrated that T. yunnanense alone achieved a 91.04% reduction of 50 mg L-1 Cr(VI) within 72 h. Combined with 0.5% SBC, the reduction efficiency increased to 99.65% within 48 h. However, the efficiency decreased at higher concentrations (200 mg L-1). The combination also improved fungal growth and increased extracellular ChrR enzyme activity (13.07 U mg-1 protein compared to the control). Total glutathione activity was boosted by 161.07% at 100 mg L-1 Cr(VI). Antioxidant enzymes (SOD, POD, CAT) and proline mitigated oxidative stress and FTIR analysis revealed changes in fungal cell wall functional groups (-OH and -NH) upon Cr(VI) exposure. SEM-EDX confirmed chromium deposition on fungal surfaces. These results underscore the Cr(VI) detoxification capabilities of T. yunnanense and the synergistic benefits of SBC, suggesting a promising bioremediation strategy for Cr(VI)-contaminated environments. The integration of T. yunnanense with SBC offers a sustainable and cost-effective approach for the bioremediation of Cr(VI)-contaminated sites, with potential for implementation in large-scale environmental cleanup efforts.

Green synthesis of graphene oxide and magnetite nanoparticles and their arsenic removal efficiency from arsenic contaminated soil.

Graphene-based nanomaterials have been proved to be robust sorbents for efficient removal of environmental contaminants including arsenic (As). Biobased graphene oxide (bGO-P) derived from sugarcane bagasse via pyrolysis, GO-C via chemical exfoliation, and magnetite nanoparticles (FeNPs) via green approach using Azadirachta indica leaf extract were synthesized and characterized by Ultraviolet-Visible Spectrophotometer (UV-vis.), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), mean particle size and Scanning electron microscopy (SEM) along with Energy dispersive spectroscopy (EDX) analysis. Compared to cellulose and hemicellulose, the lignin fraction was less in the precursor material. The GOC, bGO-P and FeNPs displayed maximum absorption at 230, 236, and 374 nm, respectively. FTIR spectrum showed different functional groups (C-OH, C-O-C, COOH and O-H) modifying the surfaces of synthesized materials. Graphene based nanomaterials showed clustered dense flakes of GO-C and thin transparent flakes of bGO-P. Elemental composition by EDX analysis of GO-C (71.26% C and 27.36% O), bGO-P (74.54% C and 24.61% O) and FeNPs (55.61% Fe, 4.1% C and 35.72% O) confirmed the presence of carbon, oxygen, and iron in synthesized nanomaterials. Sorption study was conducted with soil amended with different doses of synthesized nanomaterials (10, 50 and 250 mg) and exposed to 100, 300 and 500 ppm of As. Arsenic concentrations were estimated by colorimetry and atomic absorption spectroscopy (AAS). GO-C, bGO-P, and FeNPs showed substantial As removal efficiency i.e., 81 to 99.3%, 65 to 98.8% and 73.1-89.9%, respectively. Green synthesis of bGO-P and magnetite nanoparticles removed substantial amounts of As compared to GO-C and can be effectively deployed for As removal or immobilization. Higher and medium sorbent doses (250 and 50 mg) exhibited greater As removal and data was best fitted for Freundlich isotherm evidencing favorable sorption. Nevertheless, at low sorbent doses, data was best fitted for both models. Newly synthesized nanomaterials emerged as promising materials for As removal strategy for soil nano-remediation and can be effectively deployed in As contaminated soils.

A comparative evaluation of the composition and antioxidant activity of free and bound polyphenols in sugarcane tips.

The sugarcane tip is abundant in phenolic compounds. Previous studies have concentrated on the effects of free polyphenols, while bound polyphenols were overlooked. In this study, the content of bound polyphenols (SPB) (31.9 ± 0.9 mg GAE/g DW) was significantly higher than free polyphenols (SPF) (3.4 ± 0.1 mg GAE/g DW). A total of 44 free and 31 bound phenolics were identified by the UPLC-EIS-QTOF-MS/MS. Moreover, the antioxidant activity of SPB was more pronounced, as evidenced by its higher ABTS+ and DPPH scavenging rates than SPF, which was attributed to the higher tannin content. Furthermore, at all tested concentrations (100 and 200 µg/mL), SPB significantly enhanced the survival and antioxidant enzyme activity of Caenorhabditis elegans (C. elegans), while concurrently reducing ROS levels. High concentrations of SPB even exhibited antioxidant activity comparable to Vitamin C (Vc). The collective findings strongly indicate that SPB holds great potential as an effective antioxidant.

From cane to nano: advanced nanomaterials derived from sugarcane products with insights into their synthesis and applications.

Sugarcane-based products are inherently rich in elements such as silicon, carbon and nitrogen. As such, these become ideal precursors for utilization in a wide array of application fields. One of the appealing areas is to transform them into nanomaterials of high interest that can be employed in several prominent applications. Among nanomaterials, sugarcane products based on silica nanoparticles (SNPs), carbon dots (CDs), metal/metal oxide-based NPs, nanocellulose, cellulose nanofibers (CNFs), and nano biochar are becoming increasingly reported. Through manipulation of the experimental conditions and choosing suitable starting precursors and elements, it is possible to devise these nanomaterials with highly desired properties suited for specific applications. The current review presents the findings from the recent literature wherein an effort has been made to convey new development in the field of sugarcane-based products for the synthesis of the above-mentioned nanomaterials. Various nanomaterials were systematically discussed in terms of their synthesis and application perspectives. Wherever possible, a comparative analysis was carried out to highlight the potential of sugarcane products for the intended purpose as compared to other biomass-based materials. This review is expected to stand out in delivering an up-to-date survey of the literature and provide readers with necessary directions for future research.

This review focuses on sugarcane-derived nanomaterials such as silica, nano cellulose, nanofibers, nanocrystals and metal/nonmetal nanoparticles and their application in various energy and environmental fields.

Synthetic redesign of Escherichia coli W for faster metabolism of sugarcane molasses.

BACKGROUND: Sugarcane molasses, rich in sucrose, glucose, and fructose, offers a promising carbon source for industrial fermentation due to its abundance and low cost. However, challenges arise from the simultaneous utilization of multiple sugars and carbon catabolite repression (CCR). Despite its nutritional content, sucrose metabolism in Escherichia coli, except for W strain, remains poorly understood, hindering its use in microbial fermentation. In this study, E. coli W was engineered to enhance sugar consumption rates and overcome CCR. This was achieved through the integration of a synthetically designed csc operon and the optimization of glucose and fructose co-utilization pathways. These advancements facilitate efficient utilization of sugarcane molasses for the production of 3-hydroxypropionic acid (3-HP), contributing to sustainable biochemical production processes. RESULTS: In this study, we addressed challenges associated with sugar metabolism in E. coli W, focusing on enhancing sucrose consumption and improving glucose-fructose co-utilization. Through targeted engineering of the sucrose utilization system, we achieved accelerated sucrose consumption rates by modulating the expression of the csc operon components, cscB, cscK, cscA, and cscR. Our findings revealed that monocistronic expression of the csc genes with the deletion of cscR, led to optimal sucrose utilization without significant growth burden. Furthermore, we successfully alleviated fructose catabolite repression by modulating the binding dynamics of FruR with the fructose PTS regulon, enabling near-equivalent co-utilization of glucose and fructose. To validate the industrial applicability of our engineered strain, we pursued 3-HP production from sugarcane molasses. By integrating heterologous genes and optimizing metabolic pathways, we achieved improvements in 3-HP titers compared to previous studies. Additionally, glyceraldehyde-3-phosphate dehydrogenase (gapA) repression aids in carbon flux redistribution, enhancing molasses conversion to 3-HP. CONCLUSIONS: Despite limitations in sucrose metabolism, the redesigned E. coli W strain, adept at utilizing sugarcane molasses, is a valuable asset for industrial fermentation. Its synthetic csc operon enhances sucrose consumption, while mitigating CCR improves glucose-fructose co-utilization. These enhancements, coupled with repression of gapA, aim to efficiently convert sugarcane molasses into 3-HP, addressing limitations in sucrose and fructose metabolism for industrial applications.

Regulatory Network of the Late-Recruited Primary Decarboxylase C4NADP-ME in Sugarcane.

In agronomically important C4 grasses, efficient CO2 delivery to Rubisco is facilitated by NADP-malic enzyme (C4NADP-ME), which decarboxylates malate in bundle sheath cells. However, understanding the molecular regulation of the C4NADP-ME gene in sugarcane (Saccharum spp.) is hindered by its complex genetic background. Enzymatic activity assays demonstrated that decarboxylation in sugarcane Saccharum spontaneum predominantly relies on the NADP-ME pathway, similar to sorghum (Sorghum bicolor) and maize (Zea mays). Comparative genomics analysis revealed the recruitment of eight core C4 shuttle genes, including C4NADP-ME (SsC4NADP-ME2), in the C4 pathway of sugarcane. Contrasting to sorghum and maize, the expression of SsC4NADP-ME2 in sugarcane is regulated by different transcription factors (TFs). We propose a gene regulatory network for SsC4NADP-ME2, involving candidate TFs identified through gene co-expression analysis and yeast one-hybrid experiment. Among these, ABA INSENSITIVE5 (ABI5) was validated as the predominant regulator of SsC4NADP-ME2 expression, binding to a G-box within its promoter region. Interestingly, the core element ACGT within the regulatory G-box was conserved in sugarcane, sorghum, maize, and rice (Oryza sativa), suggesting an ancient regulatory code utilized in C4 photosynthesis. This study offers insights into SsC4NADP-ME2 regulation, crucial for optimizing sugarcane as a bioenergy crop.

Genome sequence of the sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae).

The sugarcane aphid, Melanaphis sacchari (Zehntner, 1897), is an agricultural pest that causes damage to plants in the Poaceae (the grasses) family, such as sorghum and sugarcane. Here, we used Nanopore long reads and Hi-C interaction map to generate a chromosome-level assembly with a total length of 356.1 Mb, of which 85.5% (304.6 Mb) is contained within the three autosomes and the X chromosome. Repetitive sequences accounted for 16.29% of the chromosomes and a total of 12,530 protein-coding genes were annotated, achieving 95.8% benchmarking universal single-copy orthologs (BUSCO) gene completeness. This offers a substantial improvement compared to previous low-quality genomic resources. Phylogenomic analysis by comparing M. sacchari with twenty-four published aphid genomes representing three aphid tribes reveals that M. sacchari belongs to the tribe Aphidini and maintained a conserved chromosome structure with other Aphidini species. The high-quality genomic resources reported in this study will be useful for understanding the evolution of aphid genomes and studying pest management of M. sacchari.

Production of Polyhydroxybutyrate by halotolerant Halomonas cerina YK44 using sugarcane molasses and soybean flour in tap water.

As environmental pollution intensifies, the interest in bioplastics is growing. The bioplastic polyhydroxyalkanoates (PHAs), which are produced and degraded by microorganisms, have received considerable attention. However, the production cost of PHA is still high, and several ways to increase economy of PHA production have been studied. Therefore, as one way of solution, Halomonas species were screened and evaluated with cheap substrates such as molasses and soybean flour. Among tested strains, Halomonas cerina YK44 was selected and used for polyhydroxybutyrate (PHB) production with molasses and soybean flour together, whose combination was not evaluated well before, in tap water. The medium composition optimization showed maximum PHB production at 4 % sugarcane molasses, 2 % NaCl, 0.05 % soybean flour, and pH 8 in tap water (9.2 g/L DCW, 7.3 g/L PHB, and 79.7 % PHB contents). However, cell growth of halotolerant H. cerina YK44 was disturbed by 0.2 % furfural, which existed in biomass based sugars as inhibitors. Physical and thermal analyses revealed that PHB film started from sugarcane molasses and soybean flour was no different from that initiated from simple sugars (Tm was 175.8 °C and 176.2 °C, PDI was 1.29, and 1.31, respectively).

Nephroprotective effect of sugarcane (Saccharum officinarum L.) leaves ethanol extract on gentamicin-induced nephrotoxicity in rats.

Kidney damage is commonly attributed to using certain drugs, such as gentamicin, which causes elevated kidney parameters in blood and damage to renal tissue. This damage is often a result of oxidative stress, but it can be mitigated by using antioxidants. Several studies proved the potential of sugarcane (Saccharum officinarum L.) leaves as an antioxidant. Therefore, this experiment aimed to examine the nephroprotective action of sugarcane leaves. Twenty-five Wistar rats were separated into the normal, negative, and sugarcane leaf extract (SLE) (200, 400, and 600 mg/kg BW) groups. The animals were handled for 8 days, and then, the blood and tissue were collected 24 h later. The results revealed that SLE prevents increased creatinine, blood urea nitrogen, uric acid, and malondialdehyde levels. The histology analysis indicated that the extract improved kidney morphology and histopathology. Sugarcane leaves have the potential to be a nephroprotective agent.

Establishment of efficient system for bagasse bargaining: Combining fractionation of saccharides, recycling of high-viscosity solvent and dismantling.

Sugarcane bagasse (SCB) has a recalcitrant structure, which hinders its component dismantling and subsequent high value utilization. Some organic solvents are favorable to dismantle lignocellulose, but their high viscosity prevents separation of components and reuse of solvents. Herein, ethylene glycol phenyl ether (EGPE)-acid system is used as an example to develop green and efficient methods to dismantle SCB, purify polysaccharides and lignin, and reuse solvents. Results show that dismantling SCB at 130 °C, 0.5 % H2SO4, and 100 min can obtain 85.5 % cellulose recovery, 94.1 % hemicellulose removal and 83.7 % lignin removal. Different molecular weight saccharides are separated by membranes filtration and centrifugation, and lignin recovered by antisolvent precipitation. The solvent recovered by distillation, achieving high dismantling efficiency of 89.2 % cellulose recovery, 94.1 % hemicellulose removal and 94.4 % lignin removal after four recycles. Results show a promising approach for the closed-loop process of dismantling lignocellulose, fractionating saccharides, and reusing solvents in high-viscosity systems.

Scalable mesoporous biochars from bagasse waste for Cu (II) removal: Process optimisation, kinetics and techno-economic analysis.

As the world faces the brink of climatological disaster, it is crucial to utilize all available resources to facilitate environmental remediation, especially by accommodating waste streams. Lignocellulosic waste residues can be transformed into mesoporous biochar structures with substantial pore capacity. While biochars are considered a method of carbon dioxide removal (CDR), they are in fact an environmental double-edged sword that can be used to extract metal ions from water bodies. Biochars possess high chemical affinities through chemisorption pathways that are tuneable to specific pH conditions. This work demonstrates how biochars can be enhanced to maximise their surface area and porosity for the removal of Cu (II) in solution. It was found that bagasse derived mesoporous biochars operate preferentially at high pH (basic conditions), with the 1.18 mKOH/mSCB material reaching 97.85% Cu (II) removal in 5 min. This result is in stark contrast with the majority of biochar adsorbents that are only effective at low pH (acidic conditions). As a result, the biochars produced in this work can be directly applied to ancestral landfill sites and carbonate-rich mine waters which are highly basic by nature, preventing further metal infiltration and reverse sullied water supplies. Furthermore, to assess the value in the use of biochars produced and applied in this way, a techno-economic assessment was carried out to determine the true cost of biochar synthesis, with possible routes for revenue post-Cu being removed from the biochar.

VirB11, a traffic ATPase, mediated flagella assembly and type IV pilus morphogenesis to control the motility and virulence of Xanthomonas albilineans.

Xanthomonas albilineans (Xal) is a gram-negative bacterial pathogen responsible for developing sugarcane leaf scald disease, which engenders significant economic losses within the sugarcane industry. In the current study, homologous recombination exchange was carried out to induce mutations within the virB/D4-like type IV secretion system (T4SS) genes of Xal. The results revealed that the virB11-deletion mutant (ΔvirB11) exhibited a loss in swimming and twitching motility. Application of transmission electron microscopy analysis further demonstrated that the ΔvirB11 failed to develop flagella formation and type IV pilus morphology and exhibited reduced swarming behaviour and virulence. However, these alterations had no discernible impact on bacterial growth. Comparative transcriptome analysis between the wild-type Xal JG43 and the deletion-mutant ΔvirB11 revealed 123 differentially expressed genes (DEGs), of which 28 and 10 DEGs were notably associated with flagellar assembly and chemotaxis, respectively. In light of these findings, we postulate that virB11 plays an indispensable role in regulating the processes related to motility and chemotaxis in Xal.

Effect of Dietary Sugarcane Bagasse on Reproductive Performance, Constipation, and Gut Microbiota of Gestational Sows.

This experiment aimed to evaluate the effects of using sugarcane bagasse (SB) as a substitute for soybean hulls and wheat bran in the diet of pregnant sows on their reproductive performance and gut microbiota. A total of seventy-two primiparous sows were randomly divided into four treatment groups, with eighteen replicates of one sow each. The sows were fed a basal diet supplemented with 0% (CON), 5%, 10%, and 15% SB to replace soybean hulls from day 57 of gestation until the day of the end of the gestation period. The results showed that SB contains higher levels of crude fiber (42.1%) and neutral detergent fiber (81.3%) than soybean hulls, and it also exhibited the highest volumetric expansion when soaked in water (50 g expanding to 389.8 mL) compared to the other six materials we tested (vegetable scraps, soybean hulls, wheat bran, rice bran meal, rice bran, and corn DDGS). Compared with the CON, 5% SB significantly increased the litter birth weight of piglets. Meanwhile, 10% and 15% SB significantly increased the rates of constipation and reduced the contents of isobutyric acid and isovaleric acid in feces. Furthermore, 10% and 15% SB significantly disturbed gut microbial diversity with increasing Streptococcus and decreasing Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group genera in feces. Interestingly, Streptococcus had a significant negative correlation with isobutyric acid, isovaleric acid, and fecal score, while Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group had a positive correlation with them. In conclusion, our study indicates that 5% SB can be used as an equivalent substitute for soybean hulls to improve the reproductive performance of sows without affecting their gut microbiota.

Metarhizium caribense sp. nov., a Novel Species of Entomopathogenic Metarhizium Fungi Associated with Weevils Impairing Coffee, Sugar Cane and Sweet Potato Cultivation.

(1) Background: Insect pathogenic fungi of the genus Metarhizium are under study and in application as highly solicited, more eco-system friendly substitutes for chemical insecticides in many countries and in different agricultural contexts. In Cuba and Florida, Metarhizium strains have previously been isolated from economically important coffee and sugar cane pests. (2) Methods: Unambiguous species delineation within the Metarhizium anisopliae species complex is methodologically challenging. Recently, a species-discriminating PCR approach has been developed based on ribosomal intergenic spacer (rIGS) sequences that covered the prominent four "PARB" species within the complex. This approach is combined here with further genetic markers and is extended to a further species. (3) Results: Metarhizium isolates from Cuba, found to be more naturally associated with the coffee berry borer, Hypothenemus hampei, were morphologically, microscopically and molecular taxonomically characterized. Multilocus sequence analysis based on 5TEF, MzIGS3 and rIGS markers delineated these weevil-associated strains from all previously established Metarhizium species. (4) Conclusions: The isolates under study represent a new fungal taxon proposed to be designated Metarhizium caribense. The rIGS-based species-discriminating diagnostic PCR is a suitable tool for the identification of new Metarhizium species and can be productively combined to approaches using further genetic markers.

Two Sugarcane Expansin Protein-Coding Genes Contribute to Stomatal Aperture Associated with Structural Resistance to Sugarcane Smut.

Sporisorium scitamineum is a biotrophic fungus responsible for inducing sugarcane smut disease that results in significant reductions in sugarcane yield. Resistance mechanisms against sugarcane smut can be categorized into structural, biochemical, and physiological resistance. However, structural resistance has been relatively understudied. This study found that sugarcane variety ZZ9 displayed structural resistance compared to variety GT42 when subjected to different inoculation methods for assessing resistance to smut disease. Furthermore, the stomatal aperture and density of smut-susceptible varieties (ROC22 and GT42) were significantly higher than those of smut-resistant varieties (ZZ1, ZZ6, and ZZ9). Notably, S. scitamineum was found to be capable of entering sugarcane through the stomata on buds. According to the RNA sequencing of the buds of GT42 and ZZ9, seven Expansin protein-encoding genes were identified, of which six were significantly upregulated in GT42. The two genes c111037.graph_c0 and c113583.graph_c0, belonging to the α-Expansin and ß-Expansin families, respectively, were functionally characterized, revealing their role in increasing the stomatal aperture. Therefore, these two sugarcane Expansin protein-coding genes contribute to the stomatal aperture, implying their potential roles in structural resistance to sugarcane smut. Our findings deepen the understanding of the role of the stomata in structural resistance to sugarcane smut and highlight their potential in sugarcane breeding for disease resistance.

Dissection of genetic architecture for desirable traits in sugarcane by integrated transcriptomics and metabolomics.

Sugarcane is an important sugar and energy crop. Breeding varieties with high yield and sugar, strong stress tolerance, as well as beneficial for mechanized harvesting are the goal of sugarcane breeder. In the present study, transcriptomics and metabolomics were conducted to explore the molecular basis for outstanding performance of five elite varieties GT42, GT44, LC05-136, YZ08-1609, and YZ05-51, along with the cross-parent CP72-1210 compared to ROC22. Transcriptomics revealed a total of 18,353 differentially expressed genes (DEGs) and several regulatory pathways, including carbon fixation, starch and sucrose metabolism, phenylpropanoids biosynthesis, flavonoid biosynthesis, cysteine and methionine metabolism, as well as zeatin biosynthesis. Expression patterns of genes involved in these pathways confirmed their role in determining the agronomic traits. Besides, metabolomics disclosed 175 differentially accumulated metabolites (DAMs), including specific metabolites of amino acids and secondary metabolites. Furthermore, conjoint analysis of transcriptomics and metabolomics highlighted the manipulation of 113 genes led to changed levels of 20 metabolites associated with carbon fixation, sucrose accumulation, phytohormone response and secondary metabolism. Finally, we depicted here a blueprint outlining the genetic basis underlying the desirable traits in sugarcane. This study will accelerate the dissection of the molecular basis for sugarcane traits and provide targets for molecular breeding.

Soil dissipation and efficacy on itchgrass of soil-applied residual herbicides pendimethalin and clomazone in Louisiana sugarcane.

BACKGROUND: Sugarcane (Saccharum sp.) growers in Louisiana report that the widely used soil residual herbicide, pendimethalin, is less effective at controlling itchgrass (Rottboellia chochinchinensis), possibly through accelerated dissipation from repeated applications. Some growers have started to use another herbicide, clomazone, in place of pendimethalin for itchgrass control when pendimethalin does not provide the necessary control. Little is known about the dissipation of these two herbicides, especially when applied together, in diverse sugarcane soils in Louisiana. Thus, the objective of the research was to measure the dissipation of pendimethalin and clomazone in soils having high itchgrass pressure. Soil samples from five fields were fortified (4 µg g-1) with clomazone and pendimethalin and monitored over the course of 163 days under laboratory conditions. Herbicide levels were determined by extracting the herbicides from soil with acetonitrile and analyzing the extracts with high performance liquid chromatography (HPLC). RESULTS: The results indicate that clomazone is persistent in the soils studied, with a degradation half-life (DT50) of ≥79 days. Pendimethalin dissipates more rapidly in soil with a DT50 ranging from 7 to 59 days. All itchgrass plants showed injury to herbicide but many grew out of symptoms, and responses were not consistent between soil types. CONCLUSION: Pendimethalin dissipation varied greatly between soil types, yet clomazone was generally persistent in each soil tested. However, when these soils were seeded with itchgrass, pendimethalin was more effective at controlling itchgrass than clomazone. Although persistent in the soils tested, the leaching potential of clomazone may limit its long-term effectiveness. Published 2024. This article is a U.S. Government work and is in the public domain in the USA.