Effect of certain inorganic chemicals on growth and spore germination of Alternaria tenuis auct., the fungus causing core rot of mandarin oranges in India

Summary Laboratory studies to determine the tolerance of an isolate ofAlternaria tenuis causing a black core rot of mandarin oranges (Citrus reticulata) have shown that presence of low amounts of manganese, zinc, iron, copper, boron, and molybdenum in a synthetic medium stimulated growth and sporulation of the fungus. Concentrations of 20 ppm or more of copper sulphate, boric acid, and ammonium molybdate, however, caused significant reduction of growth. Conidia of the fungus were very sensitive to even low amounts of copper, zinc, and iron. Copper sulphate was most toxic to spore germination followed, in order of inhibitory effect, by zinc sulphate, ferrous sulphate, and boric acid. Ammonium molybdate and manganese sulphate were stimulatory to spore germination at 5 ppm. There was a positive correlation between percentage of spore germination and average length of germ tubes in different concentrations of various chemicals. The possibility of using copper sulphate, zinc sulphate, and ferrous sulphate as spray materials for trees and as dip for ripe fruits to prevent black core rot are discussed.Assoc. Professor and Research Assistant, respectively. Publication under journal series No. 27 from Experiment Station, U.P. Agricultural University.     

Effect of zinc on cadmium toxicity to the amphipod Gammarus pulex

The freshwater amphipod Gammarus pulex was sampled from several sites in Northumberland, England and analysed for total body zinc and cadmium concentrations.The toxicity of cadmium to animals from the different sites was determined and a positive relationship was found between the initial total body zinc concentration and the ability to survive in an artificial medium containing 0.5 mg 1^–1 cadmium as cadmium sulphate.Exposure in the laboratory to a low concentration of zinc (0.01 mg 1^–1) as zinc sulphate for two weeks resulted in a decreased susceptibility to cadmium poisoning.     

Sulphur requirements of certain isolates ofAlternaria tenuis Auct

The sulphur nutrition of three isolates ofAlternaria tenuis Auct., isolated from the diseased leaves ofMangifera indica L.,Musa paradisiaca L. andPsidium guajava L., was studied. They were grown on the medium devoid of sulphur as well as on media containing various sources of sulphur viz., ammonium sulphate, sodium hyposulphite, sodium thiosulphate, magnesium sulphate, potassium sulphate, potassium metabisulphite, zinc sulphate and thiourea. Sodium hyposulphite, sodium thiosulphate, magnesium sulphate, potassium sulphate and zinc sulphate were generally found to be satisfactory sources for the growth of all the isolates under study. Poor growth of the different isolates was observed on the medium devoid of sulphur.     

Some physiological studies in two species of phytophthora

Summary The paper deals with some physiological studies viz., (1) Production of enzymes (2) Effect of chemicals and sugar solutions and (3) Utilization of amino acids, by two species ofPhytophthora i.e.,Phytophthora palmivora Butler andP. parasitica Dast. var.macrospora Ashby., isolated from rotten fruits ofAchras sapota andAnona squamosa respectively.In the study of production of extra-cellular enzymes, it was found that both the isolates ofPhytophthora produced enzymes like inulase, amidase, emulsin and diastase in small quantity.Among the various chemicals and salt solutions used to study their effects in the formation of sporangia; it was observed that these were remarkably produced in abundance by both the species ofPhytophthora specially in the chemical solutions like sodium chloride, potassium nitrate, sodium thiosulphate and potassium permanganate. On the other hand, chemical solutions like strontium sulphate, potassium chromate, ammonium oxalate, zinc sulphate, copper sulphate, potassium sulphate, strontium nitrate and ferrous sulphate completely ceased the sporangial development. Among the various sugar solutions tried, dextrose, galactose, glucose, laevulose and fructose accelerated sporangial formation.An attempt was also made to study the effect of various amino acids singly or in combination on growth and sporulation. Both the isolates under study, utilized L-Arganine monohydrochloride and DL-Aspartic acid, hence these were growth promoters. It is interesting to note that the growth of the isolates was good, only when DL-Norleucine and DL-Methionine (both growth inhibitors) were provided in combination.Forms a part of Senior author's M.Sc. (Agriculture) Thesis, University of Poona, (Poona) India.Respectively, Ex-Jr. Res. Fellow, I.C.A.R. New Delhi; Professor of Plant Pathology and Principal, College of Agriculture, Junagad (Gujarat); and Plant Pathologist, Wheat Rust Research Station, Mahabaleshwar (Poona), India.     

重金属对黄瓜籽苗发育影响的研究

选用黄瓜(Cucumis sativus)籽苗为材料,硫酸铜,醋酸铅、硫酸锌、氯化镉和氯化镍为化学处理试剂,研究它们对黄瓜籽苗的生长及其根尖细胞有丝分裂的影响。发现随着化学处理试剂浓度的增大,黄瓜籽苗根长度、苗高度、侧根数和最长侧根的长度均有所下降,其中下降最明显的是根长度。同样,根尖细胞有丝分裂的细胞数量明显减少,细胞分裂速率减慢。5种重金属盐中,硫酸铜的毒性最甚,氯化镉、醋酸铅次之。     

Effect of supplementation of micronutrients and phytochemicals to fructooligosaccharides on growth response of probiotics and E. coli

Probiotics and prebiotics, which can change the colonic microenvironment, are the areas of current interest. Unutilizable fractions of the foods and fortificants, which reach the colon can affect the profile of probiotics. Effects of eight such factors viz. zinc sulphate, zinc carbonate, ferrous sulphate, ferric citrate, quercetin, gallic acid, phytic acid, and oxalic acid were, therefore, investigated on 24 H growth of Lactobacillus acidophilus (L1) and Lactobacillus plantarum (L2), two isolates of bifidobacteria (longum (L3) and bifidum (L4)) and a marketed consortium (L5) of eight probiotic cultures. MRS medium with marketed fructooligosaccharide as the only source of carbon was used for study of dose response curves. Quercetin and zinc sulphate showed significant positive effect for L1 and L5 (P < 0.01), whereas there was slight positive effect or no effect on growth of other probiotics. Phytic acid showed a significant inhibitory effect for L2 and a slight inhibitory effect on L3 and L4 whereas L5 were able to tolerate phytic acid. Oxalic acid had slight positive effect for L1 (P < 0.05) and L5 and no effect on growth of other probiotics (P > 0.05). Further, zinc sulphate, ferrous sulphate, quercetin, and oxalic acid significantly inhibited growth of E. coli (P < 0.05)     

重金属对黄瓜籽苗发育影响的研究

选用黄瓜(Cucumis sativus)籽苗为材料,硫酸铜、醋酸铅、硫酸锌、氯化镉和氯化镍为化学处理试剂,研究它们对黄瓜籽苗的生长及其根尖细胞有丝分裂的影响。发现随着化学处理试剂浓度的增大,黄瓜籽苗根长度、苗高度、侧根数和最长侧根的长度均有所下降,其中下降最明显的是根长度。同样,根尖细胞有丝分裂的细胞数量明显减少,细胞分裂速率减慢。5种重金属盐中,硫酸铜的毒性最甚,氯化镉,醋酸铅次之。     

Experimental studies on toxicity of zinc to a freshwater teleost,rasbora daniconius (Hamilton)

Rasbora daniconius (Ham.) were exposed to zinc sulphate upto 15 days under static bioassay test conditions with renewal of the test solutions every 24 hours. Simultaneously control fish were also kept in water without zinc. The 96 and 240 hr LC₅₀ values were 38.1 and 33.3 PPm of zinc respectively. A reduced mortality rate was observed after 96 hr and LC₅₀ approached a constant value at 240 hr of exposure to the toxicant. Fish showed abnormal behaviour, deposition of mucus and appearance of haemorrhage on the body in case of higher concentrations of zinc, before death. The reported LC₅₀ values in the present study were comparatively higher than those reported by earlier investigators.See offprint requests to: Dr. V. K. Rajbanshi, Department of Limnology and Fisheries, University of Udaipur, Udaipur-313001, India.     

THE TOXICITY OF ZINC SULPHATE TO RAINBOW TROUT

The toxicity of zinc sulphate to rainbow trout ( Salmo gairdnerii Richardson) has been investigated in waters of different chemical and physical properties.
Zinc sulphate was less toxic to rainbow trout in hard water than in soft water; when the log concentration of zinc was plotted against log median period of survival of the fish the dose response curve was linear in a very soft water, and curvilinear in a hard water, approaching an apparent threshold concentration. Solutions of zinc sulphate containing calcium chloride were less toxic than those containing an equivalent concentration of calcium as bicarbonate.
An increase in temperature decreased the survival time of rainbow trout in solutions of zinc sulphate in a hard water, but the threshold concentration was not appreciably affected by changes in temperature.
A reduction in the dissolved oxygen concentration of the water increased the toxicity of zinc sulphate, but the effect was reduced when the fish were previously acclimatized to the lower oxygen concentration of the test.
The cause of death of fish in solutions of zinc sulphate was not by the precipitation of mucus on the gills but probably by damage to the gill epithelium.     

Contact allergy and sociodemographic characteristics

The aim of the study was to determine the frequency of positive patch test reaction to different contact allergens according to patients age, sex, occupation and clinical features. Between 1999 and 2003, patch testing was performed in 3,293 patients with respective clinical diagnoses. Patch testing was done by the standard technique proposed by the International Contact Dermatitis Research Group (ICDRG). Study results showed statistically significant differences in patch test response according to sex and age for three allergens (cobalt chloride, nickel sulphate and thiomersal); according to occupation for nine allergens (cobalt chloride, nickel sulphate, balsam of Peru, fragrance mix, thiuram mix, wood tars, neomycin sulphate, thiomersal and detergents), and clinical diagnosis for two allergens (nickel sulphate, and wood tars). The most common and relevant allergens were: nickel sulphate, cobalt chloride and carba mix. They were found in all examinees regardless of age, sex, occupation and diagnoses. The increased awareness of allergens and their potential sources may help to limit the usage of these chemicals in manufacture of consumer products.     

Effects of inorganic amendments (N,P and K) to soil on the rhizosphere microflora of antirrhinum plants infected withVerticillium dahliae Kleb

Summary A study of the inorganic amendments (N, P and K) to soil, and their effect on the rhizosphere microflora, as well as their relation to the control of wilt of antirrhinum plants caused byVerticillium dahliae Kleb. was done. Ammonium sulphate was the only chemical found to be significantly inhibitory toV. dahliae in vitro. Soil amendments (NPK) affected the rhizosphere microorganisms of the antirrhinum plants. Higher concentration of the chemicals were phytotoxic. It was further observed that ammonium sulphate, and the combined chemicals (NPK 25%) in soil delayed the senescence in healthy plants, suggests that chemical fertilisers affected the host plants directly. Addition of ammonium sulphate (0.25%), calcium nitrate (0.25%, 0.5%) combined NPK (0.25%) to soil caused considerable reduction in disease severity. It is assumed that this reduction may be caused by the (1) fungitoxic nature of the chemicali.e. ammonium sulphate, (2) antagonistic environment for the pathogen in the rhizosphere was boostedi.e. where calcium nitrate was added as soil amendments and (3) reduction in disease severity in soil-amended with combined NPK, may be due to the fact that antagonistic actinomycete population was boosted in the rhizosphere.     

Effects of fungicides and surfactants on the zoospores of Olpidium brassicae

Lettuce big-vein disease is transmitted from diseased to healthy plants by zoospores of the lettuce root-infecting fungus Olpidium brassicae. A laboratory technique based on microscopical examination of Olpidium Zoospores is described for assaying the toxicity of chemicals to zoospores. Chemcials found to kill zoospores in <1 h included copper (4 μ/ml), zinc (10μ/ml), diluted preparations of carbendazim (methyl-2-yl-benzimidazole carbamate) as Bavistinand a formulation of Bavisitin containing no carbendazim. Bavistn controlled the disease when introduced at a concentration of 0.6 g/litre into a lettuce crop grown in a re-circulated film of nutrient. Various surfactants inlcuding Agral, Cetrimide, Deciquam, Ethylan CPX, Hyamine 1622, Manoxol/OT and sodium lauryl sulphate were toxic to zoospores at concentrations of 1–10 μ/ml.     

Effects on Myzus persicae (Sulz.) and transmission of beet yellows virus of applying certain trace elements to sugar beet

Applications of lithium chloride (LiCl), zinc sulphate (ZnSO₄) or nickel sulphate (NiSO₄) to the roots of sugar-beet plants in the glasshouse encouraged settling on the leaves of adult apterae from a clone of Myzus persicae (Sulz.); conversely, treatment with boric acid (H₂B₂O₇) inhibited aphid settling. Larviposition of M. persicae was increased by NiSO₄ and tin chloride (SnCl₂). Viruliferous M. persicae transmitted beet yellows virus (BYV) more efficiently to plants treated with LiCl or H₂B₂O₇ than to those treated with copper sulphate (CuSO₄), ZnSO₄ or SnCl₂. The sulphate and chloride anions of the applied chemicals appeared to have little effect on M. persicae and virus transmission. It is suggested that applications of trace elements to sugar beet affected M. persicae and virus transmission by changing the concentrations of trace elements in the aphids' diet and by altering the metabolism of the leaf tissues in the host plant.     

The action of nabam, metham-sodium and other sulphur compounds on Heterodera schachtii cysts

When used in tests against eggs of Heterodera schachtii, sodium ethylenebisdithiocarbamate (nabam) solutions break down to give a number of compounds, some being hatch-inhibiting and others hatch-stimulating. The compound mainly responsible for the hatch-stimulating activity of nabam solutions is ethylenethiuram monosulphide. Stored solutions of sodium ethylenebisdithiocarbamate lose activity because the ethylenethiuram monosulphide disappears. Zinc and manganese ethylenebisdithiocarbamates were more active hatching agents than equimolar mixtures of zinc or manganese sulphates with nabam. Hatch stimulation was least with a zinc sulphate/nabam mixture of mole ratio 1.5:1, in which the dithiocarbamate ion became largely replaced by the sparingly soluble zinc dithiocarbamate. Increasing the zinc concentration in the mixture increased hatching because of the hatching activity of the zinc ion. Nabam solutions containing manganese sulphate were inactivated because the manganese ion catalysed decomposition to the hatch-inhibiting carbon disulphide. Sodium N-methyldithiocarbamate (metham-sodium, Vapam), which readily decomposed in aqueous solution, was toxic to, and prevented the hatching of, H. schachtii. Methylisothiocyanate, the major decomposition product, was toxic to H. schachtii at concentrations greater than 0.1 mM.     

Sulphur and phosphorus requirements of Curvularia pallescens Boed

The effect of different sulphur and phosphorus compounds on the growth and sporulation ofCurvularia pallescens Boed. has been studied. Nine different sulphur sources were tried but among them only magnesium sulphate yielded the best dry weight of the fungus. Zinc sulphate, sodium sulphate, sodium thiosulphate, potassium sulphate and calcium sulphate supported good growth. Poor growth was recorded on sodium bisulphite, ammonium sulphate, sodium sulphide and control. Sporulation was excellent on magnesium sulphate. It was good on zinc sulphate, sodium sulphate and potassium sulphate. On sodium thiosulphate, calcium sulphate, sodium bisulphite and control it was fair. Sodium sulphide and ammonium sulphate had inhibitory effect as sporulation was poor and nil on these two compounds respectively.Six phosphorus compounds were studied. Tripotassium phosphate gave best growth and excellent sporulation. Good growth and excellent sporulation was recorded on monobasic potassium phosphate and magnesium phosphate. Growth and sporulation were good on dibasic potassium phosphate and sodium dihydrogen phosphate. Ammonium phosphate was poorly utilized.     

Beneficial effects of combination of P and Zn for green gram (Phaseolus aureus L.)

Summary Dicalcium phosphate dihydrate and potassium dihydrogen phosphate were applied to calcareous soil in combination with zinc sulphate in the molar ratio of 100∶0, 100∶1, 100∶2 and 100∶4. Increasing addition of zinc sulphate into P sources gradually increased KCl (0.01M) soluble P and Zn, NaHCO₃ (0.5M, pH 8.5) extractable P and DTPA extractable Zn from soil and grain and straw yields of green gram.     

Field and glasshouse experiments on the control of potato mop-top virus

Field observations during 3 yr on a stock of potato cv. Red Craigs Royal partially infected with potato mop-top virus (PMTV) confirmed that the virus was passed by an infected mother plant to only a proportion of its progeny tubers, and showed that in this cultivar symptomless plants gave rise only to symptomless progeny. The elimination of PMTV from stocks can therefore be greatly accelerated by removing symptom-bearing plants. Infected potato tubers were not freed from PMTV by treating them at 37 °C for up to 8 wk. Treating ‘seed’ tubers bearing powdery scabs that contain PMTV-carrying resting spores of Spongospora subterranea with formaldehyde or organo-mercurial fungicide greatly decreased PMTV establishment when the tubers were planted in previously uninfective soil, but fumigation with 2-aminobutane was ineffective. Decreasing the pH of infective soil to 5-0 by applying sulphur greatly decreased the infection of potato cv. Arran Pilot with PMTV and S. subterranea in field experiments, but this treatment did not eliminate either; when the pH of treated soil was raised the transmission of PMTV resumed. Treating infective soil with a range of fungicides greatly decreased the infection of Nicotiana debneyi bait seedlings in glasshouse experiments but only calomel at 75 kg/ha controlled spread of PMTV and 5. subterranea to potato in field experiments. In other field experiments, applying zinc frit, zinc sulphate or zinc oxide to infective soil greatly decreased the spread of both to potato. The amount of zinc required increased with increase in clay content of the soil. However, treatment with zinc compounds did not eliminate PMTV-carrying vectors from soil, and when treated soil was diluted with autoclaved soil many of the bait seedlings planted in the mixture became infected. The zinc frit was phytotoxic because of its boron content but zinc sulphate and zinc oxide caused little or no decrease in tuber yield. The zinc content of potato tubers was increased but not doubled in zinc-treated plots, and during the first year after treatment the zinc content of topsoil decreased greatly. The zinc content of ryegrass grown after potatoes was greater than of potato tubers but did not reach a level considered dangerous to livestock. Treatment of soil with sulphur, zinc oxide or calomel may be useful for small plots used in the early stages of propagation of virus-tested potato clones where there is risk of infection with PMTV.     

Effect of reducing the top concentration used in the in vitro chromosomal aberration test in CHL cells on the evaluation of industrial chemical genotoxicity

A current concern with in vitro mammalian cell genotoxicity testing is the high frequency of false or misleading positive results caused in part by the past use of excessively high test concentrations. A dataset of 249 industrial chemicals used in Japan and tested for genotoxicity was analyzed. Of these, 116 (46.6%) were positive in the in vitro chromosomal aberration (CA) test, including 6 that were positive only at test concentrations >10mM. There were 59 CA-positive chemicals at test concentrations ≤ 1mM. At >1mM, 51 chemicals were CA-positive, including 13 Ames-positive chemicals, which were therefore not "missed" by the test battery. Thus, 38 potentially positive chemicals would not have been detected in the test battery if the top test concentration was limited to 1mM in CA test. Analysis of the relevance of CA results on the 38 missed chemicals was conducted based on a weight of evidence approach, including evaluations of effects of extreme culture conditions (low pH, high toxicity, or precipitation), in silico structural alert analysis, in vivo genotoxicity and carcinogenicity test data (where available), mode of action, or information from closely related chemicals. After an exhaustive review, there were four chemicals with some concern for human health risk assessment, nine with minimal concern, and the remaining 25 with negligible concern. We apply different top concentrations to the 38 missed chemicals to identify the most accurate approach for predicting the genotoxicity of industrial chemicals. Of these 2mM or 1mg/mL, whichever is higher, was the most effective in detecting these chemicals, i.e., relatively higher (8/13) or lower (17/25) detection among 13 chemicals with some or minimal concern, or 25 with negligible concern, respectively. Lower top concentration limits, 1mM or 0.5mg/mL, whichever is higher, are not as effective (2/13) for detecting these chemicals with concern. Therefore, we conclude 2mM or 1mg/mL, whichever is higher, would be an appropriate top concentration limit for testing industrial chemicals for chromosome damage.     

Selected zinc metabolism parameters in women with arterial hypotension

In the present study, differences between selected zinc parameters in healthy women and arterial hypotension patients were compared. The patients had baseline systolic blood pressure that did not surpass 100 mmHg. During the orthostatic test, a decrease of over 20 mm Hg was seen and the patients reported dizziness, limpness, and palpitations. The patients had higher levels of lymphocyte zinc than those of the controls and exhibited a positive correlation between serum zinc and the ouabain-dependent zinc efflux from lymphocytes (r=0.49), and, in turn, this efflux was negatively correlated to the serum aldosterone level (r=−0.35). Except for the differences in their systolic blood pressure and lymphocyte zinc, none of the tested zinc metabolism parameters showed significant differences between the patients and the controls. As in arterial hypertension, the obtained results indicate that zinc plays a significant role in regulation of arterial blood pressure.     

The mouse spot test. Evaluation of its performance in identifying chemical mutagens and carcinogens

The published results on 60 chemicals and X-rays investigated in the mouse spot test were compared with data on the same chemicals tested in the bacterial mutation assay (Ames test) and lifetime rodent bioassays. The performance of the spot test as an in vivo complementary assay to the in vitro bacterial mutagenesis test reveals that of 60 agents, 38 were positive in both systems, 6 were positive only in the spot test, 10 were positive only in the bacterial test and 6 were negative in both assays. The spot test was also considered as a predictor of carcinogenesis; 45 chemicals were carcinogenic of which 35 were detected as positive by the spot test and 3 out of 6 non-carcinogens were correctly identified as negative. If the results are regarded in sequence, i.e. that a positive result in a bacterial mutagenicity test reveals potential that may or may not be realized in vivo, then 48 chemicals were mutagenic in the bacterial mutation assay of which 38 were active in the spot test and 31 were confirmed as carcinogens in bioassays. 12 chemicals were non-mutagenic to bacteria of which 6 gave positive responses in the spot test and 5 were confirmed as carcinogens. These results provide strong evidence that the mouse coat spot test is an effective complementary test to the bacterial mutagenesis assay for the detection of genotoxic chemicals and as a confirmatory test for the identification of carcinogens. The main deficiency at present is the paucity of data from the testing of non-carcinogens. With further development and improvement of the test it is probable that the predictive performance of the assay in identifying carcinogens should improve, since many of the false negative responses may be due to inadequate testing.