Evaluation of Grapevines for Resistance to Downy Mildew (Plasmopara viticola) under Laboratory and Field Conditions

Downy mildew of grapevine (Vitis vinifera L.), caused by the oomycete Plasmopara viticola, can seriouslydevastate grapevine production in tropical countries, such as Thailand. Four susceptible grapevinecultivars, four potentially resistant lines and 18 F1 hybrids, propagated by air layering and chip budding,were evaluated for resistance to downy mildew at laboratory (using a detached leaf assay) and field (naturalinfection in 2011 and 2013) levels. Significant differences in the disease scores among grapevine genotypes,ranging from 0.54 (resistant) to 4.83 (susceptible) and 3.30 (resistant) to 7.70 (susceptible), were observedunder the laboratory and field conditions respectively. No significant difference in disease severity wasobserved between the two propagation methods or between the two different years of field evaluations.Resistance evaluations under both conditions consistently classified ‘NY88.0517.01’ and ‘NY65.0550.04’ asresistant lines what would be useful as parents for future breeding programmes. Moreover, one F1 hybrid,‘SUT0403.09’, was reported to have considerable resistance to downy mildew under both laboratoryand field conditions for the first time. The field resistance level of this hybrid was almost comparable toits highly resistant parent ‘Wilcox 321’, suggesting its potential for the future development of resistantcultivars in Thailand. Although the ranking of genotypes varied between screening methods, the resistancelevels of the 26 grapevine genotypes evaluated under laboratory and field conditions were comparablebased on the Spearman’s rank correlation coefficients of 0.73 (p ≤ 0.01). These results suggest that thelaboratory screening assay is efficient for the rapid, reliable and economical identification of resistanthybrids in grapevine breeding programmes

Banana Peel (Musa ABB cv. Nam Wa Mali-Ong) as a Source of Value-Adding Components and the Functional Properties of Its Bioactive Ingredients

\ua9 2024 by the authors.Banana peel (BP) is the primary by-product generated during banana processing which causes numerous environmental issues. This study examines the physical attributes, proximate analysis, glycoarray profiling, antioxidant abilities, and prebiotic activity of BP. The analysis demonstrated that carbohydrates constituted the primary components of BP and the glycoarray profiling indicated that BP contains multiple pectin and hemicellulose structures. BP also contained phenolic compounds, including (+)-catechin and gallic acid, flavonoid compounds, and antioxidant activities. BP demonstrated prebiotic effects by promoting the proliferation of advantageous gut bacteria while inhibiting the growth of harmful bacteria. The prebiotic index scores demonstrated that BP exhibited a greater capacity to promote the growth of beneficial bacteria in comparison to regular sugar. The study demonstrated the potential of the BP as a valuable source of dietary fibre, bioactive compounds, and prebiotics. These components have beneficial characteristics and can be utilised in the production of food, feed additives, and functional food

Field Diagnosis of Groundnut Diseases

Diseases ar e major constraints to groundnut production throughout the world. This handbook is designed to assist agricultural research and extension workers, wh o may have little formal training in plant pathology, to make tentative diagnosis of diseases of groundnut caused by 31 fungi, 2 bacteria. 9 viruses, a mycoplasma-like organism, 4 nematodes, and a parasitic flowering plant. The most characteristic field symptoms of each disease are Illustrated and descr ibed. It is emphasized that for confirmation of field diagnosi s the assistance of skilled plant pathologists will be requi red in most cases

Field Diagnosis of Groundnut Disease. Information Bulletin No 36(revised)

Diseases are major constraints to groundnut production throughout the world. This handbook is designed to assist agricultural research and extension workers, who may have little formal training in plant pathology, to make tentative diagnosis of diseases of groundnut caused by 29 fungi, 2 bacteria, 11 viruses, a mycoplasma-like organism, 4 nematodes, and a parasitic flowering plant. The most characteristic field symptoms of each disease are illustrated and described. It is emphasized that for confirmation of field diagnosis the assistance of skilled plant pathologists will be required in most cases

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

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

โครงการหนึ่งอาจารย์หนึ่งผลงา

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

Exploring Interdigitated Electrode Arrays Screen-Printed on Paper Substrates for Steady-State Electrochemical Measurements

This research explores the use of interdigitated electrode arrays (IDE) screen-printed on paper substrate for electrochemical measurements in steady state. Since the steady state is strongly related to IDE dimensions, the accuracy and reproducibility of the fabrication process were assessed for stencils of 120- and 200-mesh. Simulations were used to predict the limiting current and time response, and as a benchmark for comparison with the experimental results. For accurate an comparison, evaporation was prevented by using a homemade humidity box, which enabled measurements for periods as long as 30 min. Although cyclic voltammetry measurements in steady state were possible, this required at least 15 min per cycle when using the smallest electrodes (band width of 0.205 mm). Chronoamperometric measurements reaching steady state were also possible, requiring nearly 5 min for the largest electrodes (band width of 0.376 mm). Regarding the reproducibility of measurements, the relative standard deviations (RSD) of current and response time were near 12% and 26%, respectively. We attribute this mainly to the reproducibility of IDE fabrication (8% RSD). Experimental currents were approximately 30% to 34% of their simulated counterparts. Conversely, the simulated response times were about 30% to 50% of their experimental counterparts. We ascribe these discrepancies to the porosity of the paper (Whatman 2 CHR), estimated to be near 31% under wet conditions. This suggests that fibers inside the paper substrate block the passage of electrochemical species, thereby delaying their diffusion and decreasing the current. (C) 2022 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited

In vitro inhibition of pathogenic Verticillium dahliae, causal agent of potato wilt disease in China by Trichoderma isolates

Twenty (20) of Verticillium dahliae were isolated from wilted potato specimens collected from six districts in Guizhou, China. All the isolates were evaluated for pathogenicity on two potato cultivars, Favorita (susceptible) and Hui-2 (resistant) using the root dip inoculation (RDI) and microsclerotia inoculation (MI). All of the V. dahliae isolates appeared to be pathogenic on both cultivars but VGZ-HZ-4 isolate gave the highest wilt incidence comparing to the others, seconded by VGZ-SC-1 and VGZ-XW-1. Combined analysis of wilt incidence resulting from using two inoculation methods for VGZ-HZ-4 and VGZ-XW-1 isolates on the two potato cultivars showed that the MI gave a higher wilt incidence than that of the RDI and cultivar Favorita had a higher wilt incidence than that of Hui-2. These two V. dahliae isolates were further used as representative isolates for mycelial inhibition (MyI) test with 33 Trichoderma isolates under a dual culture condition on potato dextrose agar plate. The 33 Trichoderma isolates consisting of 21 isolates isolated from potato soils from seven districts of Guizhou, 11 isolates from single spore isolates of the TGZ-150 isolate preserved at Guizhou Institute of Plant Protection (GZIPP) and one isolate TGZ-OLD-81 also preserved at the GZIPP. Most of the single spore isolates and TGZ-SC-4 were found to have higher MyI efficiency than that of the rest. The results indicate that the Trichoderma isolates in this study have initial modes of action of biological control to protect potato crop against V. dahlia.Keywords: Trichoderma, potato wilt disease, growth inhibition, Verticillium dahliae, antagonistic fungi.African Journal of Biotechnology, Vol 13(31) 3402-341

Sequences of the coat protein gene of five peanut stripe virus (PStV) strains from Thailand and their evolutionary relationship with other bean common mosaic virus sequences

The coat protein gene and part of the 3' non-coding region of five strains of peanut stripe virus (PStV) from Thailand have been cloned and sequenced. Phylogenetic comparisons of these strains, known as T1, T3, T5, T6 and T7, and related sequences showed that these strains are indeed strains of PStV. Further, PStV strains appear to be related to each other according to their geographic origin. That is, the Thai strains are more closely related to each other than they are to strains from the USA or Indonesia, despite the variety of symptoms caused by these strains and the overlap of symptom types between the strains from different locations. Like other PStV strains, PStV-Thai can be considered strains of bean common mosaic virus (BCMV) but can be distinguished from bean-infecting strains of BCMV and blackeye cowpea mosaic virus (BICMV) through sequence and host range. No evidence was found that PStV-Thai strains, unlike PStV-Ib, are recombinants of PStV and BICMV, although the T3 strain may be a recombinant of different PStV sequences. Phylogenetic analyses of viruses of the BCMV group suggest that acquisition of the ability to infect peanut may have occurred only once