Amplification Band Research Articles

Development and optimization of immunomagnetic bead separation-convective PCR (IMBS-CPCR) for on-site detection of four common Vibrio species in aquaculture

Foodborne infectious diseases, particularly those caused by pathogenic Vibrio species in aquaculture, are a significant concern in the field of seafood safety. They not only hinder the economic development of the industry but also pose a major threat to public health. Traditional detection methods are often too slow, insensitive, or impractical for portable use, highlighting the urgent need for a sensitive, on-site detection method for Vibrio that prioritizes convenience and speed. This study developed a visual IMBS-CPCR method for the detection of four common pathogenic Vibrio species: Vibrio alginolyticus, Vibrio anguillarum, Vibrio fluvialis, and Vibrio harveyi. The method achieved high capture rates for target bacteria (82.6%–83.3%) and low capture rates for non-target bacteria (below 11%), demonstrating good sensitivity by detecting bacteria at concentrations as low as 10 CFU/mL. Optimal amplification conditions were determined for each species, with specificity tests confirming that only target bacteria produced amplification bands. Sensitivity tests revealed detection limits of 101 CFU/mL for V. alginolyticus, V. anguillarum, and V. fluvialis, and 102 CFU/mL for V. harveyi. The combined techniques improved detection sensitivity in simulated fish samples by 10–100 fold compared to direct CPCR or PCR methods.

Non-invasive identification of historical textiles and leather by means of external reflection FTIR spectroscopy

Identifying the fibres in historical textiles presents a complex challenge due to the wide variety of plant, animal and early synthetic materials that have been used. Traditionally, this identification process involves sampling followed by either microscopic examination or ATR-FTIR spectroscopy. However, there are instances when sampling is restricted due to the good condition or significant value of the object under analysis. Additionally, the presence of leather components alongside textiles can further complicate the identification. This paper proposes a novel non-invasive method for fibre identification based on External Reflection (ER) FTIR spectroscopy, which has been rarely applied to textiles or leather. The current research demonstrates that ER-FTIR spectrum is a viable tool for fibre identification on both recent and historical textiles. The non-invasiveness of the analytical approach enables a comprehensive investigation without compromising the number or position of samples. Respect to ATR-FTIR spectra, the ER-FTIR spectra frequently exhibit an amplification of certain diagnostic bands, facilitating the identification of the various fibres examined in this study (cotton, hemp, viscose, silk, wool, leather, polyamide, acrylic, polyester). The extended spectral range (7500–375 cm−1) which is provided by ER-FTIR spectrometry also contains extra bands in the near infrared region, which can provide key information for the discrimination due to the lack of distortion phenomena. The technique was applied to the characterisation of textile materials coming from a collection of 10 traditional Japanese samurai armours spanning from the 16th to the 20th century (Museo delle Culture, Lugano, Switzerland). For the first time, the results provided a comprehensive overview of the textiles utilized in Japanese armours across various historical periods. Overall, the appearance of materials in samurai armours reflects the evolution of armour-making techniques and the influence of socio-cultural factors throughout Japanese history. Synthetic and semi-synthetic materials were easily detected, revealing the occurrence of a past conservation treatment or the early adoption of modern man-made materials in the manufacturing of traditional armours. The approach outlined in this case study can be applied to textile collections of various kinds, offering a reliable mean to discern the yarn composition and detect non-original components. The method also appears as a valuable prescreening tool for designing a less intrusive yet more informative sampling strategy, should additional details about fibre type and dyeing be necessary.

Special Transfer Section for Selective Rejecting and Amplification of Bands in Equalization

Special Transfer Section for Selective Rejecting and Amplification of Bands in Equalization

Effect of DNA Template Concentration on Standard Polymerase Chain Reaction

The polymerase chain reaction (PCR) was an essential fundamental procedure widely used in molecular biology to amplify specific deoxyribonucleic acid (DNA) sequences. To investigate the efficiency and specificity of PCR using DNA extracted from human blood cells as sample, several concentrations of DNA templates were used to obtain accurate and reproducible results during this optimisation process. The principal objective was to identify which concentration was the best for amplifying the DNA target sequence and study the effects of the scale of concentrations to standard PCR. For this study, a series of PCR were conducted using various concentrations of DNA template ranging from 1 ng/μL to 100 ng/μL per reaction under optimized conditions of primer concentrations, annealing temperature and extension time. The results demonstrated that DNA template concentration significantly influenced the efficiency and specificity of PCR as the intensity of the target gene amplification band was increased on the agarose gel electrophoresis under ultraviolet light indicating the PCR product yield. Formation of primer-dimers became more prominent as the DNA template concentration reduced resulting in non-specific amplification. The concentrations ranging from 10 ng/μL to 70 ng/μL were the most optimal reactions profiting a remarkable feat of target gene amplification while concentrations less than 1 ng/μL produced none and non-specific outcomes retaining little amount of target gene amplification. In conclusion, our study highlights the pivotal role of DNA template concentration optimises PCR to increase reliability and reproducibility, extending our understanding of genetic analysis, diagnostic, and forensic sciences.

Crystal field effects of Al doping on the Stark splitting and gain bandwidth of erbium doped silica fibers

In this study, erbium-doped silica fibers (EDFs) with different Al/Er ratios were prepared by high-temperature source combined with the modified chemical vapor deposition (MCVD) method. The effects of different Al/Er ratios on the gain performance of erbium-doped silica fiber amplifiers (EDFA) were investigated. The EDFA demonstrated in this paper achieves a maximum gain of 45 dB at 1560 nm when the signal power is −20 dB, while the bandwidth of 20 dB gain is up to 68 nm (1532∼1600 nm). Additionally, the effect of Al doping on the crystal field around the Er ion was analyzed and the Stark energy level distribution of the Er ions was further derived. Our approach offers a feasible solution for C + L band amplification from the perspective of Stark effect and crystal field analysis.

Primer Design for Cloning of L-arabinose isomerase Gene from Arthrobacter psychrolactophillus into plasmid pET28a(+)

A novel putative L-arabinose isomerase (L-AI) called ApL-AI with the accession number WP_110486392.1 was successfully retrieved from Arthrobacter psychrolactophilus B7 genome (Accession: NZ_QJVC01000021.1) through genome mining analysis. This study aimed to obtain the L-AI gene from the Arthrobacter psychrolactophilus B7 genome and clone it into the pET28a(+) plasmid. The primers pair designed in this study successfully amplified the gene using 60 °C of PCR annealing temperature and supported the gene amplicon to insert into the pET28a(+) to form plasmid pET28a(+)-ApLAI. It was proved by the appearance of a 1557-bp amplification band on the gel electrophoresis. The sequencing analysis also revealed that the gene was inserted in the correct direction, with the gene positioned after the promoter and finished with a terminator. Therefore, the plasmid can be used to express the ApL-AI gene to produce the ApL-AI enzyme for downstream analysis and further prospecting.

Molecular marker-assisted genetic diversity analysis in soybean cultivars from Himalayan region of Uttarakhand, India

‘Bhat’ is the soybean variety highly valued in the traditional food and therapeutic system of Uttarakhand state in the Indian Himalayan region. It is available in diverse colors, shapes, and sizes, often linked to their nutritional parameters. The present investigation was conducted to assess the diversity and genetic relatedness in ‘bhat’ genotype indigenous to the Garhwal division of Uttarakhand. 25 polymorphic simple sequence repeats (SSR) markers were used to determine the genetic diversity and varietal identification among the 45 genotypes collected from the different villages of Uttarakhand. Out of the different markers assessed only 13 primers showed amplification with the maximum of 2–4 alleles obtained with each primer with the molecular weight ranging between 80 and 400 kb. The highest band amplification was observed in Satt 257 and Satt 197. The allelic frequencies of amplified primers ranged from 0.5 to 0.833 with a mean value of 0.645 and the mean gene diversity and PIC value was found to be 0.43 and 0.33. Satt 183, Satt 288, and Satt 389 showed the highest polymorphism, while Satt257 and Satt245 exhibited the presence of unique alleles in some samples. The phylogenetic analysis grouped the genotypes into 4 major clusters having visually distinct phenotypes in each group, indicating the mixing of population and loss of authenticity also confirming that phenotypic attributes are not indicative of genetic relatedness among the genotype under study. The results indicate the need for the development of novel ‘bhat’ specific markers for more accurate genetic identification of the nutritionally rich indigenous soybean variety.

CRISPR du-HITI an attractive approach to targeting Long Noncoding RNA HCP5 as inhibitory factor for proliferation of ovarian cancer cell.

This research provides a glimmer of hope that the knockout of HCP5 leads to a therapy response to considerably prolong the life of patients with OC. RT-PCR evaluated the expression of lncRNA HCP5 in the ovarian cancer OVCAR-3 cell line. CRISPR knockout cell lines validated by western blot. Small genomic deletions at the targeted locus were induced. CCK-8 colony formation assays were used to analyze the effect of HCP5 knockout on the proliferation capacity of OVCAR-3 cells. Transwell migration and invasion assayed. Furthermore, the Sphere-formation assay isolated the most aggressive population of cancer stem cells. Bioinformatic analysis showed a significant correlation between lncRNA HCP5 up-regulation and OVCAR-3 cell proliferation. The ChIP technique assesses specific sites of interaction between transcription factors and DNA. Real-time PCR assays explored the relationship between HCP5, Hsa-miR-9-5p, CXCR4, CDH1, caspase-3, p53, bcl2 and survivin. PCR carried out amplification of the 448-bp band for sgRNA1 and sgRNA2 after the use of particular primers for HCP5. the number of breast cancer cells that moved to the bottom chamber reduced considerably after transfection with PX461-sgRNA1/2 vectors compared to the Blank control groups (P < 0.05). MTT assay designated growth curves that showed the rate of OVCAR-3 growth was significantly repressed (***P < 0.001) when compared with control OVCAR-3 cells after HCP5 knockdown. Also, the survival results of W.T cells in 24, 48 and 72 h showed 92%, 87% and 85%, respectively. This is while the cells of the CRISPR/Cas9 group in which LncRNA HCP5 was knocked out had 42% (*P < 0.05), 23%(**P < 0.01) and 14% (**P < 0.01) survival, respectively. The expression levels of caspase-3, Hsa-miR-9-5p, P53 genes in the HCP5 deletion of CRISPR/Cas9 group significantly increased than the W.T. control group; the deletion group showed a considerable reduction in HCP5 expression compared to the blank control group (3.6-fold, p < 0.01). Whereas BCL2, SURVIVIN, CXCR4, CDH1 genes expression markedly increased than in HCP5 knockout cells (5.8-fold, p < 0.05). These results indicate that CRISPR/Cas9-mediated HCP5 disruption on OVCAR-3 cell lines promotes anti-tumor biomarkers, suppressing ovarian cancer progression. Consistent with these results, HCP5 is one of the most critical lnc for the efficient proliferation and migration of OVCAR-3 cell lines.

Bandwidth extension to 1627 nm of over 20 dB gain in an erbium-doped silica fiber via two-photon absorption.

In this study, PbS/Er co-doped fibers (PEDFs) were fabricated by atomic layer deposition (ALD) combined with modified chemical vapor deposition (MCVD). A pumping scheme based on two-photon absorption at 1310 nm of PEDF is proposed for L + band amplification. Through the theoretical analysis, the local environment of Er3+ is changed due to the co-doping of PbS, which improves the two-photon absorption efficiency near 1300 nm. Compared with the 980 nm pump, the PEDFs excited by the 1310 nm pump show better amplification performance in the L + band. And in a bi-directional pumping system, PEDF achieves over 22 dB of gain in the whole L band. In particular, the bandwidth of over 20 dB gain was extended to 1627 nm with a noise figure as low as 4.9 dB. To the best of our knowledge, this is the first time that a high-gain bandwidth of L band amplification has been extended to 1627 nm. The results of unsaturated loss also show that PbS co-doping improves the two-photon absorption efficiency of PEDF to broaden the amplification bandwidth of L + band. These results demonstrate that an effective L + band amplification method is practically provided for future ultra-wideband optical communications.

A novel multicore Er/Yb co-doped microstructured optical fiber amplifier with peanut-shaped air holes cladding

Abstract The multicore fiber amplifier, as a key component in spatial division multiplexing (SDM) communication systems, presents higher technical difficulty compared to traditional multi-channel single core fiber amplifiers, which has sparked widespread attention. To achieve balance, efficiency, miniaturization, and cost-effectiveness in the performance of multi-core optical fiber amplifiers, we propose an innovative triple cladding 13-core Er/Yb co-doped microstructured fiber (13CEYDMOF). The proposed fiber features an outer cladding with peanut-shaped air holes, which enables uniform excitation of the 13 cores using a single multimode laser pump source within the inner cladding. This approach also prevents damage or aging of the fiber’s outer coating due to the pump laser. Furthermore, the design of Peanut-Shaped Air Holes effectively increases the numerical aperture (NA) of the inner cladding while reducing the outer diameter of the fiber, enhancing the fiber’s mechanical flexibility. To address the coupling difficulties caused by air holes, we bi-directionally pump the 13CEYDMOFA by utilizing a combined technique of the side winding and end pumping. The experimental results show that the 13CEYDMOFA can achieve an average gain of 23.8 dB, a noise figure (NF) of ∼4.6 dB, and an inter-core gain difference of less than 2 dB in the wavelength range of 1529–1565 nm. The in-line amplified transmission experiment demonstrates that the 13CEYDMOFA is well suited for the 13 spatial channels transmission. To the best of our knowledge, this is the first time to realize high performance telecommunication band amplification in a multicore microstructure fiber.

Non-degenerate-pump four-wave mixing kinetic inductance travelling-wave parametric amplifiers

Kinetic inductance travelling-wave parametric amplifiers (KITWPAs) have been demonstrated to achieve high gain over broad bandwidths whilst achieving near quantum-limited noise performance, properties which are extremely important for many ultra-sensitive experiments. In early KITWPA designs, the requirement for phase-matching lead to the creation of a large zero-gain gap in the centre of the gain profile where the peak gain is, which also slightly narrows down the operational bandwidth of the device. This has been mitigated in more recent designs by introducing a DC bias to the KITWPA device, which allows the gap to be tuned away from the amplification band. However, the added DC biasing requires a more complicated experimental setup and potentially leads to unwanted heat leak in the cryogenic environment. Additionally, operation with a DC bias also become challenging at higher frequencies beyond the microwave regime. In this paper, we present the concept of a KITWPA operating in a non-degenerate-pump four-wave mixing (NP-4WM) regime, whereby the injection of two pump tones along with a weak signal results in a broad, flat gain profile that removes the zero-gain gap as well as eliminates the need for a DC bias and the complexities associated with it. We demonstrate how a NP-4WM KITWPA is feasible to achieve broadband amplification at a range of frequencies, first in the microwave range where most KITWPAs reported to-date have been successfully experimentally characterised. We then extend the designs to several millimetre (mm) bands to illustrate how we can use this technique to design a broadband front-end pre-amplifier that covers several Atacama Large Millimetre/sub-millimetre Array (ALMA) Bands.

Molecular typing and integron detection of multidrug-resistant Klebsiella pneumoniae clinical isolates recovered from Baquba Teaching Hospital in Iraq

Klebsiella pneumoniae is a gram-negative bacterium that causes severe illnesses and is antibiotic-resistant. This study aimed to determine the antibiotic resistance profile and prevalence of classII and III Iintegrons and ERIC -PCR among clinical isolates of K. pneumoniae. The study was conducted between September 2022 and January 2023. Fifty isolates were obtained from 230 specimens (wounds, burns, blood, fluid, ears,urine and sputum). Macroscopic, microscopic, and biochemical assays were used to identify all K.pneumoniae isolates, which were confirmed with the genetically by 16S rRNA. All isolates were examined for various types of clinically significant antibiotic drugs. The results of resistance to antibiotics indicated resistance to Amoxilline-clavulanc acid(98%), Meropenem (38%), Ceftazidime (96%), Amikacin (48%), Trimethopri-sulfamethoxazole (58.62%) and Levofloxacin (46%).The testing for antibiotic susceptibility of the K.pneumoniaeisolate showed that 24 (48%) of the isolates were multi-drug resistant (MDR). K.pneumoniae β-lactamase producers (ESBL) appeared33(66%). Enterobacterial repetitive intergenic consensus (ERIC) amplification of 16 clinical K. pneumoniae isolates showed 14 (87.5 %) of Each of them revealed at least one amplification band. ERIC-PCR typing found two groups, A and B, with identical antimicrobial resistance patterns within the same group. While IntegronII showed that 1(6.25 %) of K. pneumoniae isolates was integrase gene positive. Class III integrons were seen in all isolates at a rate of 16 (100%).Continuous monitoring and characterization of integrons and their associated gene cassettes could be helpful in controlling the rate of antibiotic resistance by planning to take preventive measures to hinder the spread of resistant strains

All-fiber amplification of highly chirped dissipative solitons around a 1.3 micron using stimulated Raman scattering

An all-fiber amplification of highly chirped dissipative solitons (DSs) by stimulated Raman scattering in a standard passive fiber with continuous-wave pumping is demonstrated for the first time to our knowledge. DSs with a duration of 20 ps and a repetition rate of 15.6 MHz at a wavelength of 1275 nm are amplified by a pump wave at 1205 nm. On–off Raman gain dependence on the amplifier length and pump power, as well as the pumping configuration, are experimentally studied. Uniform amplification has been achieved with a net gain of 10 dB resulting in a pulse energy of 13 nJ at backward pumping. Further Raman amplification is limited by emerging the next Stokes component. The output pulses are compressed by a factor of 50 down to a duration of 400 fs. As a result, the peak power reached the level of 9 kW. The demonstrated scheme can be a simple and robust alternative to the widely used parametric amplification of chirped pulses outside the dopant amplification band, and the resulting pulses can be used in multiphoton microscopy and other applications.

Optimization of bismuth-doped fiber amplifier gain spectrum based on genetic algorithm in 1200 nm-1600 nm

With the continuous evolution of communication technology, and the rapid rise of fiber optic communication in China However, the transmission distance of fiber optic communication is limited due to its fiber loss, so fiber optic amplifier has become one of the key research topics today. Currently on the market is a large-scale commercial bait-doped fiber amplifier, although it has the advantage of low noise and high gain, its effective amplification band is only concentrated in 1530 nm-1620 nm, however, there are many important transmission band amplification there are still research gaps. As a result, the focus of this paper’s research is on optimizing the gain spectrum of a bismuth-doped fiber amplifier at wavelengths between 1200 and 1600 nm using modelling and numerical simulation. The research method of this paper is as follows: first of all, after the literature survey, this topic is using the three-energy level structure, and then collecting the data of pump light wavelength and emission absorption cross-section, signal light emission, and absorption cross-section. fit the data to the graph line, and call the genetic optimization algorithm to derive the gain spectrum optimal value. It’s found that when the pump light wavelength is 1230 nm, fiber length is 2 m, bismuth ion doping concentration is 10.0×1024 ions/m3, the signal light wavelength is 1330 m, its amplifier gain spectrum reaches a peak of 57.17 dB, which is consistent with the results of the three-layer cycle (manual search).

Modeling and numerical simulation optimization of gain spectrum of thulium-doped broadband fiber amplifier based on cat swarm algorithm

With the development of light technology, especially the maturation of WDM/DWDM technology, the demand for optical amplification of the S-band and S+ band (1450nm~1520nm) is increasing day by day, and the energy level structure of Tm3+ has energy level transitions to meet the requirements of S-band and S+ band amplification. Although thulium ion has a very complex energy level structure, TDFA is one of the most promising optical fiber amplifiers for S and S+ bands. At the same time, with the continuous development of computer technology and mathematical theory, the optimization algorithm has been rapidly developed and widely used in recent decades, based on genetic algorithm, simulated annealing algorithm, and other traditional optimization algorithms that have been proved to get good convergence speed and optimization results. In this paper, the thulium-doped fiber amplifier's gain is optimized by using a cat swarm intelligent optimization algorithm to obtain the maximum fiber length and doping concentration.

Er3+: B2O3-TeO2-ZnO-PbF2−M2O/MF (M = Li, Na, and K) glasses: An inspection of structural, thermal, optical, chromatic, and near-infrared luminescence traits for displays and potential C-band amplification

Six 1.0 mol% Er2O3-doped lead fluoride zinc borotellurite glasses comprising different alkali metal oxides and fluorides (K2O, Na2O, Li2O, KF, NaF, and LiF) have been synthesized via melting and quick-quench approach and structural, thermal, optical, chromatic, upconversion, and NIR (near-infrared) emission features and fluorescence decay times were explored. Main structural units BO3 and BO4, as well as TeO4 and TeO3, are affirmed in all glasses networks by Fourier transform infrared and Raman spectroscopy. For transition 4I13/2 →4I15/2, σemi (emission cross-section) has been assessed by applying Füchtbauer–Ladenburg and McCumber's theories. For Li2O and NaF constituting glasses, acquired peak absorption cross-section (4I15/2→4I13/2) values are 0.999 × 10−20 cm2 and 1.093 × 10−20 cm2, while σemiM (4I13/2→4I15/2) values are 1.064 × 10−20 cm2 and 1.174 × 10−20 cm2 individually. At various P (population inversion) values, calculated gain spectra revealed the C- band amplification from P = 40%.

Broadband Amplification in the 2.6–2.9 μm Wavelength Range in High-Purity Er3+-Doped Zinc-Tellurite Fibers Pumped by Diode Lasers

In recent years, great progress has been made in the technology of high-purity and ultra-dry tellurite glasses, which has enabled the creation of high-purity single-mode tellurite fibers doped with rare-earth ions. This technology has made it possible to demonstrate laser generation in the range of about 2.7 μm in erbium-doped tungsten tellurite fibers. In this paper, we present an experimental study of broadband amplification in erbium-doped zinc-tellurite fibers. Zinc-tellurite glasses containing modifying components, such as Na2O, La2O3, Bi2O3, or rare-earth metal oxides, are known to have noticeably lower phonon energy than heavy metal-tellurite systems, namely, tungsten tellurite glasses, which leads to better lasing output. The on-off gain of 30- and 60-cm long zinc-tellurite fibers has been measured in a wide range of diode pump powers. It has been shown for the first time that the amplification band is essentially extended, with pump power reaching over 250 nm (2600–2850 nm) at a peak power of about 40 W for a 30-cm long fiber.

Establishment of deer heart identification method and development of the detection kit based on mitochondrial cytochrome B gene

BackgroundDeer heart is a valuable traditional Chinese medicinal material. At present, there is no functional component or symbol component for deer heart, and it is difficult to identify them by physical and chemical methods. In this study, we established deer heart identification method based on mtDNA cytb gene, and developed a deer heart DNA detection kit. ResultsThere were specific amplification bands in reference medicinal materials and true deer hearts at 194 bp, but no amplification bands in negative control and blank control. Deer heart DNA detection kit has good specificity, reproducibility and stability, and its sensitivity can reach 0.5 mg. ConclusionsThe application of the deer heart DNA detection kit is simple and easy to operate, and the results obtained using the kit is stable, which is suitable for popularization and application.How to cite: Wang Y, Zhang L, Ai J. Establishment of deer heart identification method and development of the detection kit based on mitochondrial cytochrome b gene. Electron J Biotechnol 2023;65. https://doi.org/10.1016/j.ejbt.2023.06.003.

True-to-typeness and phytomedicinal potential in somatic embryo-derived plants of Crinum malabaricum (Amaryllidaceae): A medicinally important source of pharmaceutical biomolecules

Crinum malabaricum, Lekhak & S.R. Yadav (Amaryllidaceae) is a critically endangered bulbous plant endemic to India. Establishing an efficient plant regeneration protocol is necessary for its conservation and large-scale propagation. In the present study, regeneration was achieved through somatic embryogenesis from callus produced on MS media supplemented with various different concentrations of 2,4-D alone and in combination with N6-benzyl-adenine (BA). Different advanced stages of embryo development (globular, torpedo and cotyledonary) and maturation were obtained on MS medium, with combinations of picloram and thidiazuron (TDZ). A high rate of somatic embryos (55.89 ± 0.60) was obtained after eight weeks. SEM examinations showed the occurrence of cell clusters (embryogenic) which converted to somatic embryos. Well-developed cotyledon embryos were successfully germinated on PGRs free full and half strength MS medium, however, 94.03% of somatic embryos germinated on half-strength MS medium supplemented with 1.0 mg L−1 gibberellic acid. The true-to-type genetic conformity of regenerated plants was examined by SCoT, ISSR and RAPD primers based molecular analysis. The amplification bands produced by SCoT, ISSR and RAPD primers applied were monomorphic across all the regenerated plants. This confirmed their genetic homogeneity compared to the mother plant and also demonstrated the reliability of our somatic embryogenesis system for C. malabaricum. A rapid method for phytochemical analysis based on LC-ESI/MS exhibited better separation and analysis of galanthamine and lycorine from methanolic extracts of in vitro raised plants derived from somatic embryogenesis. The protocol developed should be helpful in reintroduction, restoration and ex situ conservation of this valuable plant in the natural condition as well as in the pharmaceutical sectors.

The relationship between vector insect populations, natural enemies, and disease incidence of tungro virus during wet and dry seasons

Abstract. Hutasoit RT, Jihad M, Listihani L, Selangga DGW. 2023. The relationship between vector insect populations, natural enemies, and disease incidence of tungro virus during wet and dry seasons. Biodiversitas 24: 4001-4007. Tungro virus is one of the most prevalent viruses affecting rice plants. The tungro virus is frequently found in rice plantations because its green planthopper vector is always present. This study aimed to determine the relationship between the population density of green planthoppers and its natural enemies with the incidence of tungro disease during the rainy and dry seasons in Lanrang, Sidenreng Rappang, South Sulawesi. The research method employed was field monitoring of the population density of green planthoppers, natural enemies, and the incidence of tungro disease. The presence of the tungro virus was confirmed by the molecular method using RTSV and RTBV-specific primers. The results showed three types of tungro vector insects: Nephotettix virescens, Nephotettix nigropictus, and Recilia dorsalis. Nephotettix virescens was the dominant vector insect, with the highest population in March and August of 101 and 51 individuals, respectively. During the dry season, the high population of the three vector insects in August was followed by a high incidence of tungro disease in September, reaching 29.38%. Symptoms of yellow leaves have been confirmed by molecular methods, which indicated that the infection was caused by RTSV and RTBV, as evidenced by the amplification of DNA bands measuring 787 bp and 1400 bp. Data on the population of vector insects and the incidence of tungro disease indicated the importance of determining the ideal time to plant to avoid the plant's susceptible phase during the peak vector population between March and August. The dominant natural enemies found during the observations included Araneus inustus, Tetragnatha maxillosa, Agriocnemis pygmaea, and Menochilus sexmaculatus. Increasing the population of natural enemies could suppress the population of vector insects.