Measurement of soil compaction tolerance of Lagestromia speciosa (L.) Pers. using chlorophyll fluorescence

Trees planted along roadsides and on public recreation areas are subjected to environmental stresses such as poor soil, air pollution and heat. However, very little information is available on the trees’ tolerance to the various stress factors faced in an urban environment in Malaysia, such as soil compaction. The effects of soil compaction on a range of chlorophyll fluorescence parameters (F₀,F_m,F_v/F_m) in foliar tissue of Lagestromia speciosa, a widely planted Malaysian street tree, were examined. Results showed that soil compaction was between 170 and 315 MPa in the study areas. Soil compaction above 180 MPa affected tree form and reduced chlorophyll fluorescence. It is concluded that chlorophyll fluorescence offers a rapid screening technique for assessing soil compaction tolerance of L. speciosa.     

Quorum sensing is required for full virulence of Vibrio campbellii towards tiger grouper (Epinephelus fuscoguttatus) larvae

The link between quorum sensing in Vibrio campbellii and its virulence towards tiger grouper (Epinephelus fuscoguttatus) was investigated using V. campbellii wild type and quorum‐sensing mutants with inactive quorum sensing or constitutively maximal quorum‐sensing activity, and signal molecule synthase mutants. The results showed that wild‐type V. campbellii is pathogenic to grouper larvae, causing more than 50% mortality after 4 days of challenge. Furthermore, the mortality of larvae challenged with the mutant with maximally active quorum sensing was significantly higher than that of larvae challenged with the wild type, whereas a higher survival was observed in the larvae challenged to the mutant with a completely inactive quorum‐sensing system. Grouper larvae challenged with either the signal molecule synthase triple mutant, the harveyi autoinducer‐1 (HAI‐1) synthase mutant and the autoinducer‐2 (AI‐2) synthase mutant showed higher survival than larvae challenged with the wild type. In contrast, larvae challenged with the cholerae autoinducer‐1 (CAI‐1) synthase mutant showed high mortality. This indicates that HAI‐1 and AI‐2, but not CAI‐1, are required for full virulence of V. campbellii towards grouper larvae. Our data suggest that quorum‐sensing inhibition could be an effective strategy to control V. campbellii infections in tiger grouper.     

不同降水年型施氮量对冬小麦水氮资源利用效率的调控

【目的】研究不同降水年型氮肥用量引起的小麦生育期耗水量、植株氮素积累与运转、产量及效率的变化,为黄土高原旱地冬小麦精准施肥提供理论依据。【方法】于2017—2020年在山西农业大学闻喜试验示范基地开展大田试验,种植制度为冬小麦后夏休闲,一年一熟。3个试验年降水量分别属于正常、干旱和湿润年型。试验设施氮量0、120、150、180、210 kg/hm² 5个处理,分析了小麦耗水量、氮素吸收与利用、产量形成及不同降水年型间的差异。【结果】不同降水年型旱地小麦生育期总耗水量均以N 180 kg/hm²最高,且丰水年和欠水年耗水变化率以施N 150～180 kg/hm²最高,平水年则以施N 120～150 kg/hm²最高。与其他施氮处理相比,丰水年施N 180 kg/hm²提高了播种—拔节期植株氮素积累量,显著提高了花前叶片和穗轴+颖壳氮素运转量,平水年和欠水年施N 150 kg/hm²提高了播种—拔节期植株氮素积累量及花前叶片和茎秆+叶鞘氮素运转量。不同降水年...     

Genetic diversity and conservation of two threatened dipterocarps(Dipterocarpaceae) in southeast Vietnam

Two threatened dipterocarp species,Dipterocarpus costatus and Dipterocarpus alatus are well-known endangered species in lowland forests of southeastern Vietnam,primarily from habitat loss and over-exploitation of their wood.To develop conservation strategies for these species,we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of D.alatus and three of D.costatus,representing the natural range of dipterocarps in Southeast Vietnam.Results indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for D.alatus and 0.152 for D.costatus.Results of bottleneck tests indicated a reduction in population size of both species(P>0.05).Genetic differentiation among populations was high(FST=0.347 for D.costatus and 0.274 for D.alatus),indicating limited gene flow(Nm=0.662 for D.costatus and 0.47 for D.alatus)and isolated populations related to geographical distances.Analysis of molecular variance showed high genetic variation within populations(72.92%for D.alatus and 60.81%for D.costatus)compared to among populations.Bayesian analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical distances.These results will provide a platform for the conservation,management and restoration of these species.     

Alleviation of arsenic toxicity by phosphate is associated with its regulation of detoxification,defense, and transport gene expression in barley

Arsenic(As) contamination in soils has posed a severe threat to safe crop production. The previous studies showed the antagonism between phosphorus(P) and As in plant growth and As uptake, while the mechanisms of alleviating As toxicity by P is not completely clear. Due to the limiting P condition, it is imperative to understand how low P addition can be used to suppress arsenate As(V) uptake and the subsequent mechanisms involved. Thus in this study we investigated the effect of P addition on As uptake, anti-oxidative enzyme activity, and anti-oxidant content, and the relative expression of transport, defense, and detoxification genes using two barley genotypes differing in As toxicity tolerance. P addition significantly reduced As concentration in plant tissues, and caused the great changes in activities of catalase and superoxide dismutase, glutathione content, and the relative expression of examined genes when the plants of the two barley genotypes were exposed to 100 μmol L~(–1) As, with ZDB160(As-tolerant) being much more affected than ZDB475(As-sensitive). The current results show that P addition can alleviate As toxicity by regulating the expression of As transport, defense, and detoxification genes to a greater extent in As tolerance of barley, suggesting the possibility of controlling As uptake and toxicity by applying low amount of P fertilizers in the As-contaminated soils.     

Physicochemical characterization and formation of glyphosate-laden nano-emulsion for herbicide formulation

A nano-emulsion system was developed for pesticide formulation. Pseudoternary phase diagrams were constructed consisting emulsion system of long-chain fatty acid methyl esters (LFAMEs)/mixed surfactant/water and a quarternary component, glyphosate isopropylamine (IPA) as a herbicide active. Isotropic (L) regions were formed in the phase diagrams using mixed surfactant long-chain alkylpolyglucosides (LAPG) and ethoxylated 3-(3-hydroxypropyl)-heptamethyltrisiloxane (organosilicone) at the ratios of 9:1, 8:2 and 7:3. Pre-formulation concentrates were chosen from the L regions with less than 20% (w/w) of inerts (LFAMEs + mixed surfactant) and were characterized with regard to particle size, particle aging rate and thermostability study. A pre-formulation concentrate with the lowest aging rate and stable at high temperature (54 °C) was selected for the mechanisms study of the pre-formulation concentrate in conjunction with the development of nano-emulsion formulation. The transmission electron microscopy (TEM) result showed that the pre-formulation concentrate appeared as a polymerized multi-connected network. Upon water dilution of the pre-formulation concentrate with gentle stirring (low-energy emulsification method), well-dispersed nanoparticles were formed with no needle structure being observed. The nano-emulsion particles were incorporated well with the glyphosate IPA thus inferring that this nano-emulsion system could ameliorate the bioactivity and bioavailability of the herbicide.     

Mechanical and electrical properties of photocured jute fabric with 2-hydroxy ethylacrylate

Jute fabric (hessian cloth) was grafted with 2-hydroxy ethylacrylate (HEA) and aliphatic urethane diacrylate oligomer (M-1200) under UV radiation at different intensities (16, 20, 30, 40, 50, and 60 pass) in order to improve the mechanical and electrical properties. The concentrations of the monomer (HEA), and oligomer (M1200), radiation dose, and soaking time were optimized with respect to mechanical property such as tensile strength (TS) of the treated and untreated hessian cloth. The 73 % HEA, 25 % oligomer (M-1200) and 2 % photoinitiator (Darocur-1116) in 1 minute soaking time showed the highest TS at 50th UV pass. The electrical properties such as dielectric constant and loss tangent of both treated and untreated sample were measured at frequency 10 kHz with the variation of temperature. It was observed that dielectric constant and loss tangent increased with increasing temperature up to the transition temperature and then decreased.     

Optimization of alkaline hydrolysis of paddy straw for ferulic acid extraction

Response Surface Methodology (RSM) via Central Composite Design (CCD) was used to optimize the alkaline hydrolysis of paddy straw to improve ferulic acid extraction. The parameters involved, namely temperature (°C), concentration of NaOH (M) and duration of extraction (h) are screened by Full Factorial Studies (FFD). The result obtained from FFD was 0.518% (5.18 mg/g). The interactions between each parameters involved were studied using Central Composite Design (CCD). Upon optimization, the percentage of ferulic acid improved from 0.518% to 0.817% (8.17 mg/g). The optimum conditions obtained from this study are 125 °C, 3.90 M, 2.30 h for temperature, concentration of NaOH and extraction time, respectively. This result shows a significant improvement than the previous published work. Details of the experimental design, statistical analysis and interpretation are discussed below.     

Plant Therapy: a Nonpharmacological and Noninvasive Treatment Approach Medically Beneficial to the Wellbeing of Hospital Patients

A green atmosphere and interaction with nature (plants and flowers) can considerably improve the human senses and sanity by decreasing the stress associated with anxiety, depression, neurotic impairment, and other psychologic symptoms. The current paper reports a therapeutic horticultural study’s findings regarding the effect of indoor foliage plants and flower arrangements on health prospects of surgical patients. Two surgical wards, ward A (with foliage plants and arranged flowers) and ward B (without foliage plants and flowers), were selected for the study. A total of 270 patients were randomly assigned to either ward to give 135 patients in each. Patients admitted to ward A had significantly more optimistic and promising health improvements than those in ward B. Provision of foliage plants and flower arrangements to the patients in ward A resulted in shorter postoperative stays, lower intake of analgesics, lower pain intensity, less stress fatigue, and improved vital signs (blood pressure, heart rate, respiration rate, body temperature) as compared to patients in ward B. Moreover, analyses showed that patients in ward A had a stronger psychologic frame of mind regarding their recovery from surgery and had more positive emotions and feelings regarding their stay in the hospital. They also felt that the ward atmosphere was more calming, pleasant, and satisfactory. Additionally, small group discussions and focal interviews with ward doctors and nurses confirmed the findings of the questionnaire that foliage plants & flower arrangements create a cherished environment in the ward, reduce patients’ stress, improve medical and psychologic status of patients, and also conveye positive messages of the hospital. These findings confirm the therapeutic value of horticultural activities, particularly in surgical patients in a stressed hospital setting.     

The Critical Studies of Fucoxanthin Research Trends from 1928 to June 2021: A Bibliometric Review

Fucoxanthin is a major carotenoid in brown macroalgae and diatoms that possesses a broad spectrum of health benefits. This review evaluated the research trends of the fucoxanthin field from 1928 to June 2021 using the bibliometric method. The present findings unraveled that the fucoxanthin field has grown quickly in recent years with a total of 2080 publications. Japan was the most active country in producing fucoxanthin publications. Three Japan institutes were listed in the top ten productive institutions, with Hokkaido University being the most prominent institutional contributor in publishing fucoxanthin articles. The most relevant subject area on fucoxanthin was the agricultural and biological sciences category, while most fucoxanthin articles were published in Marine Drugs. A total of four research concepts emerged based on the bibliometric keywords analysis: “bioactivities”, “photosynthesis”, “optimization of process’’, and “environment”. The “bioactivities” of fucoxanthin was identified as the priority in future research. The current analysis highlighted the importance of collaboration and suggested that global collaboration could be the key to valorizing and efficiently boosting the consumer acceptability of fucoxanthin. The present bibliometric analysis offers valuable insights into the research trends of fucoxanthin to construct a better future development of this treasurable carotenoid.