Fusarium Spores Research Articles

赤かび病耐病性およびデオキシニバレノール産生抑制型品種の育成状況

Fusarium head blight (FHB) or scab is one of the most serious disease for the wheat production in Hokkaido, the northern most part of Japan. Wheat production in Hokkaido accounts for about 60% of domestic wheat in Japan and yield losses resulting from rain damage, pre-harvest sprouting and FHB, are estimated at 10–20% of total production. Since some Fusarium produce mycotoxins, the government applied guideline levels of 1.1 mg/kg for DON in raw cereals for human consumption and feed material, 1.0 mg/kg in feed for various animal species and 4.0 mg/kg for cattle older than 3 months in 2002. Unlike Honshu district, there is no rainy season, humidity is usually low in the grain filling season except near the seashore or the river in Hokkaido. But it has become more frequent for wheats to be exposed to continuous rain during the maturing stage and the resistance to FHB of Hokkaido varieties is moderate to weak, not sufficient to avoid a contamination with DON. Selection and evaluation of FHB resistance are conducted by several methods, such as inoculation of a suspension of Fusarium spores onto wheat heads or inoculation by oat cultures with mist irrigation and a single floret injection method. Developing resistance lines, we also use Asian materials, such as Sumai 3, Japanese landrace and breeding materials developed at Kyushu agricultural research center, Brazilian varieties and European materials. Every materials have many inferior characters for Hokkaido conditions. Low yield potential, long culm, low qualities, susceptiveness to cold, snow molds and pre-harvest sprouting. Breeders and pathologists are actively screening and developing good resistance varieties and genetic material with excellent resistance to FHB. And DON accumulation of these material are low. The yield potential of these breeding lines are lower than‘Hokushin’, a leading variety in Hokkaido and they are still inferior in some traits, snow molds resistance, culm strength and quality. The improvement of these traits is being investigated.

Effect of spring barley protection on the production of Fusarium spp. Mycotoxins in grain and malt using fungicides in field trials

The effects of different fungicides in four-year trials with a susceptible variety of spring barley, which was grown in field conditions with two previous crops (sugar beet and corn) and artificially inoculated with spores of Fusarium, were investigated. Field trials were laid down in plots of the Agricultural Research Institute Kroměříž, Ltd. (235 m above sea level, average annual temperature 8.7°C, annual precipitation sum 599 mm) in 2000–2003. The variety Kompakt, which was very sensitive to Fusarium head blight (FHB) in other trials, was used in all the trials examined. Incidence and severity of FHB and control with fungicides were measured by deoxynivalenol (DON) contamination of grain and malt. The content of Fusarium trichothecenes was evaluated in one fraction of kernels (diameter 2.5 mm) which is used in malting technology process. In 2000 and 2001, the treatments without adjuvants were applied. In the following two years, Silwet L-77 adjuvant (0.1 l/ha) was used with different rates of water (250 and 150 l/ha in 2002 and 2003, respectively). In all years, DON content increased in most cases after the grain samples were malted. The conditions of high grain moisture, moderate temperature and high relative humidity provide an ideal environment for Fusarium growth during germination. The greatest reduction of mycotoxins was achieved using a combination of azole fungicides with tebuconazole or metconazole or a mixture of metconazole + famoxadone + flusilazole with the addition of Silwet L-77 and a low rate of water.

Comparative aggressiveness of isolates of Fusarium spp. causing head blight on wheat in Canada

Fusarium head blight (FHB) is an important disease of wheat in Canada. To supplement the development of FHB-resistant cultivars, the aggressiveness of Fusarium isolates representing eight species was investigated. Six wheat lines and cultivars were artificially inoculated with 12 isolates of F. graminearum and 6 isolates each of F. acuminatum, F. avenaceum, F. crookwellense, F. culmorum, F. equiseti, F. poae, and F. sporotrichioides at 50% anthesis. Symptoms of FHB were rated as disease severity on a 0 to 9 scale, 4, 7, 14, 21, and 28 days after inoculation, and as percentage of infected spikelets (IS) after 21 days. All species caused visible infections to the wheat lines and cultivars, but only F. graminearum, F. crookwellense, and F. culmorum resulted in severe disease development (>35% IS) and were considered highly pathogenic while the remaining species, which had <15% IS, were moderately and weakly pathogenic. There were significant differences (P < 0.05) in aggressiveness among isolates within species and in susceptibility among wheat lines and cultivars, suggesting that screening for resistance to FHB requires a mixture of several isolates. A new technique for a rapid and mass production of conidial spores of Fusarium spp. was described. This is also the first report showing that F. crookwellense is highly pathogenic to wheat.

Natural occurrence of Fusarium graminearum on adult wheat midge and transmission to wheat spikes

To determine the presence of Fusarium graminearum on wheat midges (Sitodiplosis mosellana), adult females were captured from a spring wheat (Triticum aestivum) field near Quebec City (Canada) and plated on potato dextrose agar. A mouth aspirator was used to capture live midges in sterile vials. F. graminearum was isolated from 2.1, 5.3 and 0.6% of midges captured in 1997, 1998 and 1999, respectively whereas other Fusarium spp. were isolated from 2.5% of the midges in 1999 and from none in 1997 and 1998. To verify that wheat midges can effectively transmit Fusarium spores to wheat spikes, glasshouse-grown wheat plants were exposed for five days to adult female wheat midges previously inoculated in the laboratory with F. graminearum macroconidia and also to uninoculated control wheat midges. At dough stage, the fungus was recovered from 29% of the spikes of plants that had been exposed to inoculated midges, and from none of the other plants. This is the first report of the natural occurrence of F. graminearum, and other Fusarium spp., on female adult wheat midges and of its transmission to wheat spikes by the midge.

Differentiation of allergenic fungal spores by image analysis, with application to aerobiological counts

The ability of an image analysis routine to differentiate between spores of eleven allergenic fungal genera was tested using analysis based on seven basic and up to 17 more complex features, extracted from digitised images. Fungal spores of Alternaria, Cladosporium, Fusarium, Aspergillus, Penicillium, Botrytis, Epicoccum, Exserohilum, Ustilago, Coprinus and Psilocybe were examined in a series of experiments designed to differentiate between spores at the genus and species level. Linear and Quadratic Discriminant Analysis of feature measurements, recorded for 100 to 1600 spores per taxon, differentiated between genera and species with a high level of accuracy. Genus comparisons using only seven basic features resulted in 98% accuracy for the recognition of conidia belonging to Cladosporium, Fusarium and Epicoccum. Differentiation between conidia of Aspergillus and Penicillium was the least reliable, with 56% of Aspergillus conidia correctly identified and 41% misidentified as Penicillium. At the species level, conidia of Cladosporium macrocarpum, Fusarium moniliforme (microconidia), F. oxysporum (microconidia), F. solani (macroconidia), Alternaria helianthi and A. brassicae were consistently identified with 86--100% accuracy. Reduced levels of accuracy in the identification of spores by image analysis reflected similarities between species in their spore morphology. The application of image analysis to aerobiological counting methods is discussed in relation to the results obtained.

New isolation methods and polymerase chain reaction strain discrimination techniques for natural products screening programs

A new isolation method of fungi was established by using the Percoll density gradient centrifugation. We found that the difference in the specific gravity allowed us to separate mixtures of fungal spores of Aspergillus, Fusarium, Listeromyces, Penicillium, and Trichoderma. When this technique was applied to soil samples, a wider variety of fungi were isolated compared with those obtained from an ordinary serial dilution method. For screening purposes, it is necessary to eliminate redundant strains from the strains initially isolated. For the efficient discrimination of strains, the random amplified polymorphic DNA (RAPD) method was applied. The establishment of a standard method for RAPD enabled us to minimize the deviation of Rf values between gels to less than 0.03. Conversion of the Rf values to binary matrices provided a matrix data that could be analyzed statistically. Based on the RAPD, it was possible to select genetically distinct fungal strains within a species. Key words: fingerprinting, isolation method, microbial screening, PCR, Percoll density gradient, RAPD.

In vitro activity of 6-pentyl-α-pyrone, a metabolite of Trichoderma harzianum, in the inhibition of Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici

The compound 6-pentyl-α-pyrone [6-p-p]produced by Trichoderma harzianum IMI 288012 was used in plate tests against Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici. The addition of 0·3 mg ml−1 6-p-p to agar medium caused a 69·6% reduction of growth of Rhizoctonia solani and 31·7% reduction of growth of Fusarium oxysporum f. sp. lycopersici after 2 d. When used in spore germination tests 0·45 mg ml−1 6-p-p was found to inhibit completely the germination of Fusarium spores. A strong relationship was found between the production of the pyrone by T. harzianum and the antagonistic ability of this fungus in vitro.

Induction and accumulation of phytoalexins in cowpea roots infected with a mycorrhizal fungusGlomus fasciculatum and their resistance toFusarium wilt disease

The interaction of a vesicular-arbuscular mycorrhizal fungusGlomus fasciculatum with a wilt-causing soil borne pathogen,Fusarium oxysporum, was studied in cowpea (Vigna unguiculata). It was found that pre-establishment by vesicular-arbuscular mycorrhizal fungus reduced the colonization of the pathogen and the severity of the disease, as determined by reduction in vascular discolouration index. In mycorrhizal plants, the production of phytoalexin compounds was always higher than in the nonmycorrhizal plants. There appeared to be a direct correlation between the concentration of the phytoalexins and the degree of mycorrhizal association. Three different compounds withR f values of 0.23 (I), 0.17 (II) and 0.11 (III) were obtained from mycorrhizal plants. Similar compounds were also found to be induced by an abiotic elicitor CuSO4. The first compound was identified as an isoflavonoid, daidzein and the other two remain to be identified. These compounds were checked for their antifungal activityin vitro. The germination of conidial spores ofFusarium oxysporum was strongly inhibited by the compound III than the other two. It is argued that the production of phytoalexin compounds in mycorrhizal plant could be one of the mechanisms imparting tolerance of the plants to wilt disease.

Occurrence of airborne spores of fungi causing grain mould over a sorghum crop

Airborne spores of Fusarium, Curvularia and Alternaria species which cause sorghum grain mould were monitored over rainy season crops of the grain-mould susceptible sorghum hybrid CSH 1 using a Hirst spore trap. Spore trapping began at the flowering stage (GS 61) and was continued beyond grain maturity (GS 92). Spores of all three fungal genera were present during the post-flowering stages. However, more spores were trapped after the hard dough stage (GS 87) than at earlier growth stages. Spore content in the air increased after grain maturity (GS 92) under moist or humid conditions. Fusarium spores were most prevalent before dawn, whereas most spores of Alternaria and Curvularia were trapped during the day. The frequency of Fusarium and Alternaria spores in the two years differed while that of Curvularia was similar in both years. The predominant species isolated from surface-sterilized moulded grain on malt-streptomycin agar were A. tenuissima, F. moniliforme, C. lunata and Phoma sorghina. These results prove that spores of mould causal fungi were naturally available in the air and initiated grain mould epidemics under suitable weather conditions.

Preliminary investigation of the use of indirect immunofluorescence to detect conidia of Brunchorstiapinea

An indirect immunofluorescence staining procedure was developed for detection of Brunchorstiapinea conidia, using antiserum to conidia and a commercially prepared fluorescein isothiocyanate protein A conjugate. The procedure detected B. pinea conidia from culture, pycnidia, and spore-trap collections. Although cross reactivity occurred with spores of Fusarium spp., Sirococcus sp., Phialophora sp., Gliocladium sp., Verticillium sp., and Gelatinosporium sp., these spores were easily distinguished from those of B. pinea by size, shape, septation, and degree of fluorescence. Fluorescent B. pinea like conidia were collected in spore traps located within and outside the New York State quarantine region. However, the identity of B. pinea like conidia could not be corroborated by other methods.

Role of plant growth regulators in host-pathogen relationships

The effect of indol-3-ylacetic acid, gibberellie acid, kinetin, abscisic acid and Ethrel on the growth of mycelium, sporulation and germination of spores ofFusarium culmorum of different pathogenicity to wheat seedlings was studied. The production of gibberellins, auxins, cytokinins, ethylene and growth inhibitors by these isolates was determined as well. It has been found that most pronounced and explicit effect on growth and development in fungi was produced by Ethrel which strongly inhibited these processes. ABA proved to be a strong growth and development stimulator, though to a different extent in different isolates. GA3 strongly stimulated sporulation and spore germination in some isolates. The effect of IAA and K on growth and development in fungi was slight. More sensitive to growth regulators were the fungi in earlier stages of growth. No correlation between the pathogenicity of the isolates and their ability to produce growth regulators as well as between their susceptibility to exogenous growth substances in the processes of fungal growth and development was stated.

Contamination of Asparagus Flowers and Fruit by Airborne Spores ofFusarium moniliforme

Contamination of Asparagus Flowers and Fruit by Airborne Spores of<i>Fusarium moniliforme</i>

Glycosidic Enzyme Activity in Pea Tissue and Pea-Fusarium solani Interactions

Membrane barriers which prevent direct contact between Fusarium solani and pea endocarp tissue prevent fungal spores from inducing phytoalexin production. Conversely, preinduced host resistance responses are not readily transported from the plant across the membrane barrier to Fusarium macroconidia.Crude enzyme extracts from pea endocarp tissues partially degrade Fusarium solani f. sp. phaseoli cell walls. Activities of the glycosidic enzymes, chitinase, beta-1,3-glucanase, chitosanase, beta-D-N-acetylglucosaminidase, beta-D-N-acetylgalactosaminidase, beta-D-glucosidase, alpha-D-glucosidase, and alpha-D-mannosidase, were detected in pea endocarp tissue. If pods are challenged with Fusarium spores or chitosan, the chitinase activity of the infected tissue remains higher than water-treated pods 0.5 to 6 hours after treatment. The beta-1,3-glucanase activity increases within 6 hours in both inoculated and control tissue. Chitosanase activity was lower in tissue treated with Fusarium solani f. sp. pisi, f. sp. phaseoli or chitosan than in water-treated control tissue. Thus, the pea tissue contains glycosidic enzymes with the potential to degrade the major compounds of the Fusarium cell walls.

Reduction of the 20-carbonyl group of C-21 steroids by spores of Fusarium solani and other microorganisms. I. Side-chain degradation, epoxide cleavage, and substrate specificity.

The spores of Fusarium solani reduced the C(2)-carbonyl group, 1-dehydrogenated ring "A" and cleaved the side chain of 16alpha, 17alpha-oxidopregn-4-ene-3, 20-dione (16alpha, 17alpha-oxidoprogesterone)(I) to give the following products: 20alpha-hydroxy-16alpha, 17alpha-oxidopregn-4-en-3-one(II); 20alpha-hydroxy-16alpha, 17alpha-oxidopregna-1, 4-dien-3-one(III); 16alpha-hydroxy-17a-oxa-androsta-1, 4-diene-3, 17-dione (16alpha-hydroxy-1-dehydrotestololactone)(IV); and 16alpha, 17beta-dihydroxy-androsta-1, 4-dien-3-one (16alpha-hydroxy-1-dehydrotestosterone)(V). When II was used as a substrate, it was metabolized into III, IV, and V at a slower rate than I. Furthermore, 16alpha-hydroxy-androst-4-ene-3, 17-dione (16alpha-hydroxyandrostenedione)(X) was transformed into IV and V. Pregn-4-ene-3, 20-dione (progesterone)(XII) was transformed into androsta-1, 4-diene-3, 17-dione (androstadienedione)(VIII) and 17a-oxa-androsta-1, 4-diene-3, 17-dione (1-dehydrotestololactone)(IX), while 17alpha-hydroxy-pregn-4-ene-3, 20-dione (17alpha-hydroxyprogesterone)(VI) was converted into its 1-dehydro analogue (VII) without accumulation of any 20-dihydro compounds. Substrate specificity in the 20-reductase system of F. solani, Cylindrocarpon radicicola, Septomyxa affinis, Bacillus lentus, and three strains of B. sphaericus are demonstrated. The 20-reductase is active only on steroids having the 16alpha, 17alpha-oxido, and Delta(4)-3-keto functions. Evidence of competition between side-chain degrading enzymes and the 20-reductase for the steroid molecule and evidence of side-chain degradation followed by epoxide cleavage (and not the reverse) are presented. A mechanism for the epoxide opening by nongerminating spores of F. solani is postulated.

The microbiology of cut-away peat

Fungi occurring commonly in cut-away peat were selected for autecological study, being chosen to represent both cosmopolitan and indigenous elements of the peat flora. A fungus alien to peat,Fusarium culmorum, was also included in the study. The germination in peat of the spores of these species and their ability to grow and colonise organic material added to peat were examined. It was concluded that the cosmopolitan element was composed of efficient saprophytes but that the ability of their spores to germinate in unamended peat was limited. Although Fusarium spores germinated, the germ tubes subsequently formed chlamydospores. Only spores of the indigenous peat fungi germinated well in peat but their growth habit was not suited to the colonisation and utilisation of organic matter, added to peat, in competition with the cosmopolitan flora. The concept of ‘source potential’ is introduced to explain the variance in fungal growth from different substrate bases.

Structures and pesticidal activities of derivatives of dinitrophenols. XII. In vitro activity of C3 to C13 alpha-branched alkyldinitrophenols and their esters and ethers against the spores of Venturia inaequalis and other fungi.

AbstractThe activity in vitro of 2‐(C3 to C13 α‐branched alkyl)‐4,6‐dinitrophenols and 4‐(C4 to C13 α‐branched alkyl)‐2,6‐dinitrophenols and of their various esters and ethers was determined against the spores of Venturia inaequalis (Cooke) Wint., Botrytis cinerea Pers., Fusarium bulbigenum, Cooke &amp; Massee, var. lycopersici (Brushi) Wollenw. and Cercospora melonis Cooke. Several alkyldinitrophenols were highly active against Venturia and the 2‐alkylphenols were generally more active than the 4‐alkylphenols. The alkyldinitrophenols were not effective against the spores of Botrytis, Fusarium and Cercospora..Esterification of several lower alkyldinitrophenols to methyl carbonates gave compounds with enhanced activity, but methyl carbonates of C7 to C11 alkyl dinitrophenols showed considerably reduced activity. Esterification to ethyl‐ or other alkyl‐carbonates gave compounds with considerably reduced activity against Venturia. Esterification of 2‐isopropyl‐ and 2‐t‐butyl‐4,6‐dinitrophenols to crotonates gave compounds with enhanced activity against Venturia, but crotonates of other phenols showed reduced activity. The acrylates of several C6 to C8 alkyl dinitrophenols proved highly active. Ethers of active phenols showed considerably reduced activity.

On the Phytoalexin production of the soybean pod in reaction to Fusarium sp., the causal fungus of pod blight.

Phytoalexin (PA for short) has been defined by Müller (1954) as antibiotics which are the result of an interaction between the host and the parasite, and which inhibit the growth of microorganism pathogenic to plants. In the present paper the results are dealt, of a study on the rate of production of PA, as affected by host plant conditions, and activities of PA, using soybean (Gylcine max Mer.) and Fusarium sp. which causes pod blight.Drops of spore suspension of Fusarium were mounted on the inner surface of the seed rooms of the pods at different ages, and after centrifuging, the supernatant was tested for inhibitory action on the germination of fresh spores of Fusarium. It was found that the PA diffused distinctly into the drops placed on the young, unmatured pods, while hardly or not in the drops on the mature pods.The PA productivity of the host tissue was determined by changing daily the drops placed on given points of young pods with new spore suspension, and by measuring the inhibitory action of the diffusates on each day. It was shown that the production of PA decreased remarkably on the second day, and sank nearly to zero on the fourth day.PA in the diffusate from the pods lost most of its inhibitory activity, when heated at 100°C for 5 minutes or diluted to 1:8.

Quantitative Studies of Fungus Spores in the Air

SUMMARYTwo hundred fifty-six silicone treated slides were exposed to the air in a Pady-Rittis sampler between June, 1953, and June, 1955, and the total number of fungus spores, as well as the commonest types were determined on a cubic foot basis. An exposure of 30 min. was made daily in summer and once or twice a week in winter. Fungus spores were present throughtout the year but were seasonal in their distribution with peaks in July and August and low concentrations in winter. Numbers in summer ranged from 50 to 700/cu ft with occasional peaks to over 1300/cu ft. In the winter numbers were usually 5 to 20/cu ft.Cladosporium was present throughout the year, comprising the bulk of the spores in summer. Numbers, in the summer were usually 25 to 350/cu ft, but higher concentrations were common, with one spore load 1080/cu ft July 7, 1953. Ustilago chlamydospores were also present all year with a peak in June at harvest time, ranging from 3 to 50/cu ft in the summer with occasional spore loads up to 415/cu ft. In the winter numbers were from 1 to 10/cu ft. Puccinia urediniospores were found chiefly in June with high numbers on only a few days and in concentrations from 1.2 to 12/cu ft. Alternaria spores were seasonal in distribution with numbers ranging from 2 to 40/cu ft in the summer, with a maximum of 97.8/cu ft on July 7, 1953. Yeast, Fusarium, and basidiospores were definitely seasonal in their occurrence and appeared to be abundant following rains. Yeast cells were usually 1–40/cu ft with one high of 211/cu ft, whereas Fusarium spores were usually lower. Basidiospores were sporadic in appearance with numbers occasionally up to 75/cu ft.Spores of the following were found occasionally on the slides: Helminthosporium, Cercospora, Penicillium (or Aspergillus), Septoria, Stemphylium, Sporormia, Pleospora, Venturia-like, Leptosphaeria-like, Curvularia, Erysiphe, Heterosporium, Nigrospora-like, Cephalothecium, Monilia-like chains and Sordaria-like. Unidentified spores, usually 1-celled, made up a large portion of the spore deposit. Hyphal fragments were present throughout the year without seasonal peaks, ranging from 2 to 15/cu ft and sometimes as high as 53/cu ft.

Factors affecting survival of lyophilized fungal spores and cells.

Spores of Alternaria, Aspergillus, Fusarium, Gliocladium, Penicillium, and Pestalotia, budding vegetative cells of Ustilago, and uredospores of Puccinia graminis, P. helianthi, and Melampsora lini were lyophilized using several techniques and various conditions. The best percentage survival of the lyophilized spores and cells was obtained when the initial freezing of the spore suspensions was just low enough to keep the suspension solid until evaporative freezing conditions were reached. Freezing to very low temperatures was unnecessary. Conditions permitting fast warming of the frozen suspension resulted in increased survival. A preliminary degassing treatment greatly enhanced percentage germination, as did the conditioning of the spores in a moist atmosphere immediately after the opening of the tubes for revival of the organisms.

FURTHER EXPERIMENTS ON THE FUSARIUM BULB ROT OF NARCISSUS

Summary.1. Experiments on the inoculation of roots of Narcissus with Fusarium bulbigenum in the autumn show that, under suitable conditions of moisture and rather high temperature, the fungus is able to penetrate and destroy the roots of all varieties tested. Under similar suitable conditions it can penetrate bulbs of susceptible varieties via the parasitised roots. It is concluded that temperature conditions in England are seldom favourable to such penetration via the young roots during the autumn.2. Some evidence is given that penetration of the bulbs may take place via the old roots at the end of the growing season when soil temperature is likely to be more favourable to attack. Further work on this point is desirable.3. Gregory's statements that heavy losses from Fusarium may follow the standard hot‐water treatment against bulb eelworm, when carried out in the autumn, and that in such cases penetration usually takes place at the base of the bulb are confirmed and amplified.4. Experiments in which bulbs were hot‐water treated, with the addition of Fusarium spores to the water, at intervals during the storage period, indicate that bulbs pass through, a phase of minimum susceptibility in late August and early September, i.e. at the normal time of bathing.5. It has been shown that, where bulbs are hot‐water treated in the presence of Fusarium spores, the addition of formalin (0.1 per cent. or more) to the water materially reduces the resulting losses.6. A comprehensive series of experiments, with fourteen varieties, has been carried out during four seasons in order to test the effects of the addition of fungicide to the hot‐water bath. These experiments, for reasons which are discussed fully in the text, have not yielded any conclusive evidence on the effect of this treatment on the spread of the disease. It has been amply shown, however, that the incorporation of 0.1‐1.5 per cent. formalin in the bath has no harmful effects on foliage, date of flowering, quality and number of blooms or amount of increase in weight of bulbs during the growing season, but is often beneficial.7. Cold steeps in 0.1 per cent. mercuric chloride solution led to a retardation of the date of flowering.8. It is desirable that fungicidal treatment should take place before the normal date of hot‐water treatment, and experiments are in progress to test the efficacy of various cold steeps and dry dustings carried out in the early part of the storage season.In conclusion the writer wishes to express her thanks to Prof. W. Brown, who suggested this work, for much advice and assistance during its progress. Thanks are also due to Dr A. K. Ghamrawi who carried out some of the observations in the 1931 experiments.