Pengaruh Modifikasi Elektroda Spce dengan BI (III) pada Penentuan Cd2+dan Pb2+secara Stripping Voltammetry

Stripping voltammetri merupakan metode elektroanalitik yang dapat digunakan pada penentuan campuran logam Cd2+ dan Pb2+ tanpa dilakukan pemisahan.Pada penelitian ini digunakan metode stripping voltammetry berbasis Screen Printed Carbon Electrode (SPCE) yang dilapisi oleh bismut dengan tujuan untuk meningkatkan sensitifitas terhadap analit. Konsentrrasi Cd2+ dan Pb2+ yang digunakan 50 ppb dengan potensial deposisi -1,2 V dan potensial scan -1,4 V sampai 0,4 V. Konsentrasi bismut yang digunakan untuk melapisi SPCE yaitu 1 ppm dan 100 ppm. Modifikasi yang baik yaitu dengan menggunakan SPCE yang dilapisi bismut 1 ppm. Pada penentuan Cd2+ dan Pb2+ dalam campuran, baik Cd2+ maupun Pb2+ akan saling mempengaruhi terhadap arus puncak dan potensial puncak yang dihasilkan. Komposisi Cd2+ tanpa Pb2+menghasilkan batas deteksi baik yaitu 15,17ppb dengan kepekaan 0,163 mA/ppb, komposisi Pb2+ dengan 50 ppb Cd2+ juga memberikan hasil batas deteksi yang baik yaitu 6,38 ppb dengan kepekaan 0,076 mA/ppb

Effects of Culture Media on Phytophthora palmivora Growth, α-elicitin Production and Toxicity to Dendrobium

Four culture media were evaluated for their ability to induce Phytophthora palmivora growth and produce culture filtrate (CF), and to determine a CF concentration and culture period effective for in vitro screening of black rot resistance in Dendrobium cv. ‘Earsakul’. Mycelial fresh weights of P. palmivora cultured in potato dextrose broth (PDB; the most commonly used medium for fungi), pea sucrose broth (PSB; a medium frequently used for Phytophthora spp.), and Murashige and Skoog broth (MSB; the most popular plant tissue culture medium) were found to be significantly higher than that in the newly developed modified oat meal broth (MOMB). When the total proteins of CFs were analysed with SDS-PAGE, a protein band of 10.5 kDa MW was found in CFs from all media with the highest level in PSB. LC-MS/MS analysis identified this protein as α-elicitin that had an identical amino acid sequence to the α-elicitin hibernalin of P. hibernalis and syringicin from P. syringae. The optimum conditions for in vitro selection of Dendrobium for black rot resistance using α-elicitin-containing CFs were also determined by evaluating the CF toxicity on Dendrobium protocorm-like bodies (PLBs) when cultured in all media supplemented with 0, 30, 50 and 100% CFs for seven, 14 and 21 d. The levels of PLB necrosis varied according to medium types, CF concentrations and culture periods. The maximum percentage of PLB necrosis (100%) was obtained in PSB supplemented with 50 and 100% CFs, and the severity of PLB necrosis was highest when treated with 100% CF for 14 and 21 d

Genomic regions associated with resistance to peanut bud necrosis disease (PBND) in a recombinant inbred line (RIL) population

Parents and 318 F8 recombinant inbred lines (RILs) derived from the cross, TAG 24 × ICGV 86031 were evaluated for peanut bud necrosis disease (PBND) resistance and agronomic traits under natural infestation of thrips at a disease hotspot location for 2 years. Significant genotype, environment and genotype × environment interaction effects suggested role of environment in development and spread of the disease. Quantitative trait loci (QTL) analysis using QTL Cartographer identified a total of 14 QTL for six traits of which five QTL were for disease incidence. One quantitative trait locus q60DI located on LG_AhII was identified using both QTL Cartographer and QTL Network. Another QTL q90DI was detected with a high PVE of 12.57 using QTL Cartographer. A total of nine significant additive × additive (AA) interactions were detected for PBND disease incidence and yield traits with two and seven interactions displaying effects in favour of the parental and recombinant genotype combinations, respectively. This is the first attempt on QTL discovery associated with PBND resistance in peanut. Superior RILs identified in the study can be recycled or released as variety following further evaluations

On the control of the Heider balance model*

The Heider social balance model describes the evolution of the relationships in a social network of humans or animals. This model is built upon the concept of balance of triads consisting of friendly or hostile edges representing the state of the network. In this differential model, a leader is introduced in order to control the system and to drive the social network to a desired relationship state. Further, the stability, the local controllability, and the optimal control through leadership of the Heider model are investigated. Results of numerical experiments demonstrate the ability of the proposed control strategy to drive the Heider balance model to friendship

Combining ability for resistance in peanut (Arachis hypogaea) to peanut bud necrosis tospovirus (PBNV)

โครงการหนึ่งอาจารย์หนึ่งผลงา

Effects of Culture Media on Phytophthora palmivora Growth, α-elicitin Production and Toxicity to Dendrobium

Four culture media were evaluated for their ability to induce Phytophthora palmivora growth and produce culture filtrate (CF), and to determine a CF concentration and culture period effective for in vitro screening of black rot resistance in Dendrobium cv. ‘Earsakul’. Mycelial fresh weights of P. palmivora cultured in potato dextrose broth (PDB; the most commonly used medium for fungi), pea sucrose broth (PSB; a medium frequently used for Phytophthora spp.), and Murashige and Skoog broth (MSB; the most popular plant tissue culture medium) were found to be significantly higher than that in the newly developed modified oat meal broth (MOMB). When the total proteins of CFs were analysed with SDS-PAGE, a protein band of 10.5 kDa MW was found in CFs from all media with the highest level in PSB. LC-MS/MS analysis identified this protein as α-elicitin that had an identical amino acid sequence to the α-elicitin hibernalin of P. hibernalis and syringicin from P. syringae. The optimum conditions for in vitro selection of Dendrobium for black rot resistance using α-elicitin-containing CFs were also determined by evaluating the CF toxicity on Dendrobium protocorm-like bodies (PLBs) when cultured in all media supplemented with 0, 30, 50 and 100% CFs for seven, 14 and 21 d. The levels of PLB necrosis varied according to medium types, CF concentrations and culture periods. The maximum percentage of PLB necrosis (100%) was obtained in PSB supplemented with 50 and 100% CFs, and the severity of PLB necrosis was highest when treated with 100% CF for 14 and 21 d

Association between aflatoxin contamination and drought tolerance traits in peanut

The current study investigates the association between drought tolerance traits and aflatoxin contamination in peanut grown under long-term drought. Two field experiments were conducted at Khon Kaen University, Thailand using a split-split plot design with three drought stress levels as main plots, 11 genotypes as sub-plots, and two soil inoculations of Aspergillus flavus treatments as sub-sub-plots. The effects of temperature, soil moisture and A. flavus population on kernel colonization and aflatoxin contamination, and drought tolerance traits viz. specific leaf area (SLA) and root length density (RLD) were measured. The results demonstrated that elevated soil temperatures and reduced soil moisture, favored aflatoxin production. Drought in combination with higher levels of A. flavus inoculum load in the soil resulted in an increase in the fungal populations in the soil which in turn resulted in increased kernel colonization and subsequent aflatoxin contamination. A combination of SLA and RLD, and kernel colonization had a significant influence on aflatoxin contamination under drought conditions in both seasons (r = 0.73** and 0.76**). The results revealed that drought tolerance traits (SLA and RLD) could be contributing to resistance to aflatoxin contamination suggesting that a combination of SLA, RLD and kernel colonization could be used as selection criteria in selecting parents for aflatoxin resistance