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Lobiopa insularis (Castelnau) (Coleoptera: Nitidulidae) is a destructive pest, present in the field during the strawberry fruiting season. In this study, we characterized and quantified the damage caused by larvae and adults of L. insularis to strawberries at different ripening stages. Green, semi-ripe, and ripe strawberries were caged with larvae (n = 10) or adults (n = 5) for 72 h. Fruits at the three ripening stages were kept in cages without the presence of insects, representing the controls. The percentage values of damaged fruits varied among the ripening stages. The green strawberries were the least attacked by insects. In contrast, semi-ripe and ripe strawberries were the most prone to pest attack. Adult feeding increased the incidence of the phytopathogenic fungus Rhizopus stolonifer. The implications of these findings are discussed.

Composite dressing composed of Rhizochitosan and Regenplex™ to promote wound healing were assessed. Rhizochitosan was fabricated by deacetylation of Rhizochitin, which obtained by simply depigmenting sporangium-free mycelial mattress produced from Rhizopus stolonifer F6. Physicochemical characterizations of Rhizochitosan demonstrated that it contained 13.5% chitosan with a water-absorption ability of 35-fold dry weight and exhibiting hydrogel nature after hydration. In a wound-healing study on SD rats with full-thickness injury, the composite dressing had a better healing effect than those for each individual components and control group and wound even healed as functional tissue instead of scar tissue. The underlying mechanism of the composite beneficial to wound remodeling is likely attributable to a more reduction level of matrix metalloproteinase (MMP)-9 expression in early stage and a higher MMP-2 expression level in a later stage of healing process. Conclusively, the composite dressing demonstrated to be highly beneficial to the healing of full-thickness injury wound.

Effects of ultrasound (US, 100, 200, 300, 400, and 500 W) and hot water (HW, 25, 40, and 55 °C) treatment combination on Rhizopus stolonifer in sweet potato tuberous roots (TRs) were investigated. US (300, 400, and 500 W) simultaneous HW (55 °C) for 10 min significantly inhibited colony diameters (from 90 mm to 80.08, 65.60, and 6.00 mm) and spores germination (p

Highlights • Ultrasound (US) and slightly acidic electrolyzed water (SAEW) were combined. • US + SAEW treatment inhibited mycelial growth and spore germination of R. stolonifer. • US + SAEW treatment disrupted the cell membranes and caused the leakage of cytoplasm. • US500 + SAEW50 at 40 and 55 °C increased cell membrane permeability and decreased MMP. • US500 + SAEW50 at 40 °C and US300 + SAEW50 at 55 °C controlled soft rot decay in TRs., Effects of ultrasound (US, 300, 400, and 500 W) and slightly acidic electrolyzed water (SAEW, 10, 30, and 50 mg/L) combination on inactivating Rhizopus stolonifer in sweet potato tuberous roots (TRs) were investigated. US at 300, 400, and 500 W simultaneous SAEW with available chlorine concentration of 50 mg/L at 40 and 55 °C for 10 min significantly inhibited colony diameters (from 90.00 to 6.00–71.62 mm) and spores germination (p

This study evaluated, at a meso-scale, the antifungal effect of 405 nm LED illumination against Botrytis cinerea and Rhizopus stolonifer on tomatoes, as well as its effect of on the physicochemical properties. Tomatoes were surface-inoculated with B. cinerea and R. stolonifer, and illuminated with 87 W/m2 for twelve days. Subsequently, the antifungal effect, defined as the difference in mold populations on the control and illuminated samples, was observed to be 1.9 log CFU/g for B. cinerea and 3.2 log CFU/g for R. stolonifer. In terms of physicochemical effects, beginning from day 9, the total phenolic content, TEAC and vitamin C content of illuminated samples was significantly higher (P > 0.05) by 24.6 %, 28.2 % and 16.5 %, respectively, compared to control, but a greater reduction in mass and lycopene content was also observed. Overall, these results suggest the potential of 405 nm LEDs for controlling mold growth on tomatoes during transportation and storage, retaining their physicochemical quality.

The fungi Rhizopus stolonifer (Ehrenb.:Fr.) Vuill. (R. stolonifer (Ehrenb.:Fr.) Vuill.) and Botrytis cinerea Pers. Fr. (B. cinerea Pers. Fr.) are causal agents of important post-harvest diseases in strawberries. For their control, the essential oil (EO) extracted from the leaves of Eucalyptus staigeriana Muell. ex Bailey (E. staigeriana F. Muell. ex Bailey) and Eucalyptus urograndis W. Hill ex Maiden (E. urograndis W. Hill ex Maiden) can be a good alternative to the synthetic fungicides. Thus, the antifungal activity of the EOs from E. staigeriana F. Muell. ex Bailey and from E. urograndis W. Hill ex Maiden was evaluated in vitro on the fungi B. cinerea Pers. Fr. and R. stolonifer (Ehrenb.:Fr.) Vuill.. The effects on pathogen morphology and the in vivo antifungal activity of the EO that presented the highest activity in vitro, associated with carboxymethylcellulose (CMC), were also verified. The chemical composition of the essential oils evaluated was determined. The EO from E. staigeriana F. Muell. ex Bailey was the most efficient in the in vitro assays on the two fungi. This EO, whose major compound is limonene, caused dehydration and rupture of the fungal hyphae, suggesting its action is on the cell wall and membrane. The incorporation of this EO to CMC in the curative way reduced the severity of soft rot, caused by R. stolonifer (Ehrenb.:Fr.) Vuill.; nevertheless, it did not present an effect on the inhibition of B. cinerea Pers. Fr.. These results suggest that E. staigeriana F. Muell. ex Bailey EO, associated to CMC coating, can be an alternative to the use of synthetic fungicides for the control of R. stolonifer (Ehrenb.:Fr.) Vuill., mainly.

Post-harvest diseases of raspberries affect their storage and subsequently the ability to provide consumers with fresh products. The antifungal activity of microbial volatile organic compounds (MVOCs) against both pre and postharvest diseases has previously been demonstrated, but the control of raspberry postharvest diseases caused by Botrytis cinerea and Rhizopus stolonifer using MVOCs has not been extensively studied. We have thus investigated the effects of Bacillus siamensis G-3 volatile organic compounds (VOCs) on controlling the diseases caused by B. cinerea and R. stolonifer. Bioassays of the VOCs of B. siamensis G-3 exhibited significant control effects (89.4%) on the two pathogens. The VOCs composition was studied with solid phase micro extraction and GC/mass spectrometry (SPME-GC-MS), and 22 VOCs, different from the controls, were identified. Among these compounds, only 2, 6-di-tert-butyl-4-methylphenol (BHT), and 2,4-di-tert-butylphenol (2,4-DTBP) had significant control effects on the pathogens (*P

Blue mould caused by Penicillium expansum is one of the major pathogens causing serious losses during the postharvest and storage periods of apples and pears. Rhizopus stolonifer has also been identified as the causative agent of important rot losses in these fruit in packinghouses after humid spring seasons. An early disease detection system could help to reduce such losses. Biotic interactions affect the emission of volatile compounds during infection, and this changed the volatile profile of ‘Golden Smoothee’ apples and ‘Blanquilla’ pears inoculated with P. expansum and R. stolonifer throughout their shelf-life at 20 C for up to 7 days. Dynamic headspace-gas chromatography was used to determine if infected fruit emitted distinct volatile compounds different from those of non-infected fruit and if volatile emissions could be detected before the infection was visible in the fruit. According to the results obtained in ‘Golden Smoothee’ apples inoculated with both pathogens, Z -3-hexenyl 2-methylbutanoate could be a potential biomarker because it was quantified before these diseases were visible and was not detected in non-inoculated control fruit. Similar results were obtained for 2-butanone and α-pinene in ‘Blanquilla’ pears inoculated with R. stolonifer .

The aim of this work was to investigate the early detection of anthracnose and soft rot diseases in cold stored strawberry fruit by evaluating the CO2 and volatile organic compounds (VOCs) released by the fungi Colletotrichum fragariae and Rhizopus stolonifer. Strawberries were stored at 5, 10 and 21 °C (control group) and the VOCs and CO2 production of inoculated and non-inoculated strawberries were followed by gas chromatography. To evaluate and estimate the growth of both fungi, the CO2 data were fitted to the Gompertz model. Data of the VOCs released at the end of the fungal growth were analyzed using principal components analysis (PCA) to discriminate between infected and non-infected strawberries. The results showed that fungal growth was affected by temperature and C. fragariae had a maximum growth after 14.6 h at 5 °C and R. stolonifer at 21 °C after 45.2 h. On the other hand, through VOCs released by C. fragariae and R. stolonifer and PCA, four groups were obtained: a) strawberry infected with C. fragariae, stored at 10 °C, b) strawberry infected with R. stolonifer, stored at 21 °C, c) control group kept at 10 °C and, d) strawberry infected with C. fragariae and control group (5 and 21 °C), and strawberry infected with R. stolonifer at 5 and 10 °C. In conclusion, CO2 and VOCs released by C. fragariae and R. stolonifer on strawberries could infer the presence of anthracnose and soft rot during storage of the fruit at low temperature.

Fungal decay is a major cause of postharvest losses in strawberries. The traditional approach for controlling fungal decay is the use of fungicides. However, the use of fungicides has been questioned as a sustainable and safe method, and is also prohibited in many countries. One potential physical method for reducing fungal decay is application of a short-term hypobaric treatment prior to storage. In this study efficacy of postharvest hypobaric treatments to control natural rot development in strawberries was evaluated. Strawberries were treated with hypobaric pressures (25 kPaa, 50 kPaa and 75 kPaa) for 4 h at 20 °C and subsequently stored at 20 °C or 5 °C. A 50 kPaa treatment consistently delayed rot development in samples stored at either temperature confirming that the technique has potential as a non-chemical treatment. Moreover 50 kPaa treatments did not affect weight loss and firmness at either 20 °C or 5 °C. An initial increase in respiration rate was observed in 50 kPaa treated samples potentially indicating mild stress due to hypobaric treatment. An in vitro fungal study found that 50 kPaa treatment for 4 h did not affect the rate of radial growth of colonies of Botrytis cinerea and Rhizopus stolonifer, providing further evidence that the potential mechanism of hypobaric treatment is induction of the defence system within the fruit rather than a direct effect on fungal viability. Further molecular and biochemical research is required to evaluate the possible stimulation of resistance in fruit through short-term hypobaric treatments.

Microbial transformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1) by four filamentous fungi, Cunninghamella elegans, Macrophomina phaseolina, Rhizopus stolonifer, and Gibberella fujikuroi, afforded nine new, and two known metabolites 2–12. The structures of these metabolites were characterized through detailed spectroscopic analysis. These metabolites were obtained as a result of biohydroxylation of 1 at C-6β, -7β, -11α, -14α, -15β, -16β, and -17α positions, except metabolite 2 which contain an O-acetyl group at C-22. These fungal strains demonstrated to be efficient biocatalysts for 11α-hydroxylation. Compound 1, and its metabolites were evaluated for the first time for their cytotoxicity against the HeLa cancer cell lines, and some interesting results were obtained.

The aim of this study was to evaluate the fungicidal effect of the thyme and Mexican lime essential oils studies against Colletotrichum gloeosporioides and Rhizopus stolonifer, and to determine the possibility of incorporating them in edible coatings to control postharvest diseases of papaya fruits. For in vitro studies, both essential oils were tested to evaluate their effect on mycelial growth of C. gloeosporioides and R. stolonifer during given incubation times. For in vivo tests, fruit were dipped in the thyme and Mexican lime essential oils before and after inoculation. Non-inoculated fruits were similarly treated. A further experiment was carried out by dipping papayas in a coating formulated with both essential oils. Results indicated that the fungicidal effect was more evident with essential thyme than with Mexican lime oil. For the essential thyme oil, concentrations up to 0.060% stopped mycelial growth for both C. gloeosporioides and R. stolonifer. Papaya fruit dipped in both the essential oils experienced reduced decay caused by C. gloeosporioides and R. stolonifer by up to 50% and 40%, respectively, compared with the 100% infection observed in non-treated papayas. It was also observed that concentration was not a key factor in reducing the development of these two fungi as it occurred in in vitro studies. In papayas immersed in mesquite gum emulsion and formulated with both the essential oils, it was possible to reduce the disease incidence caused by C. gloeosporioides by 100% with the thyme and Mexican lime essential oils at 0.1% and 0.5%, respectively. Conclusion Thyme and Mexican lime essential oils demonstrated inhibitory effects against C. gloeosporioides and R. stolonifer growth in in vitro evaluations and over development of storage rots in papaya fruit. Incorporation of these two oils in mesquite gum-based coating gave excellent control of these two postharvest diseases. Significance and Impact of the Study Control of postharvest diseases of papayas by using synthetic fungicides is becoming increasingly difficult. Thyme and Mexican lime essential oils are considered as GRAS compounds. This investigation highlights the potential of using these two essential oils to control anthracnose disease and Rhizopus rot of papaya. We also confirmed that the mesquite-based gum coating formulated with thyme and Mexican lime oils accomplished what is expected in a film material: microorganism inhibition and shelf-life extension of papayas.

Eighty per cent of the total tomato postharvest losses in pre-packaged and loose tomato fruits in Mexico were caused by Alternaria rot and Rhizopus rot. A sensor was developed to detect Rhizopus stolonifer infected tomatoes using three relative humidity sensors. Green and red mature tomatoes were inoculated with R. stolonifer conidia on a wound and stored for 5 days. A small extractor sucked moist air from the tomato peduncle scar through a measuring cavity. The relative humidity of air exiting from the peduncle scar was differentiated from the ambient air relative humidity and amplified in order to obtain a value which could predict infected tomatoes. A compression surface applied a controlled pressure to green and red infected tomatoes which were detected with accuracies of 91 and 89%, respectively. Peduncle scar measurements are more useful as infected tomatoes can be monitored non-dependent on its maturity stage and within all the fruit.

The microbial transformation of leucosceptrine ( 1 ), the first member of class leucosesterterpenes, by Rhizopus stolonifer afforded two metabolites, 1α-hydroxyleucosceptrine ( 2 ), and 8α-hydroxyleucosceptrine ( 3 ).

Rhizopus stolonifer causes significant postharvest losses and about 80% of the total loss in pre-packaged and loose tomato fruits were due Alternaria rot and Rhizopus rot. The feasibility of using near infrared spectroscopy (NIR) for Rhizopus stolonifer conidia detection was studied. Visible and near infrared spectra were acquired before and after inoculating 200 tomatoes in the laboratory. The spectral data were studied using discriminant analysis, and Rhizopus stolonifer conidia were detected with an accuracy of 78%. A test set of 200 tomatoes was used for testing the algorithm, measuring the fruits only once. Spore-free and infected tomatoes were classified with an accuracy of 81 and 75%, respectively, and 96% of the infected tomatoes were properly detected by a neural network method.

Peracetic acid (PAA) treatment of stone fruits (sweet cherry, apricot, peache and nectarine) reduced the incidence of brown rot caused by Monilinia laxa and soft rot caused by Rhizopus stolonifer. The efficacy of the treatment depended on the length of time. Fruit, neither wounded nor inoculated and dipped for 1 min in a 125 mg L-1 PAA solution, showed a significant reduction of Monilinia rots with respect to control. Significant inhibition was also observed on fruit wounded and inoculated with R. stolonifer and treated for 1 min with 250 mg L-1 PAA solution. Preliminary experiments were also conducted to determine the effects of sodium bicarbonate (SBC) sodium propionate (Na-Pro) and potassium sorbate (K-Sorb), substances generally regarded as safe (GRAS) against pathogens. Phytotoxic effects appeared on fruit treated with SBC at the minimum effective concentration (3%). Only K-Sorb at 1.5% was able to significantly reduce Monilinia infections in sweet cherries (61.6%), apricots (78%) and nectarines (31.8%) with respect to control, without any visible damage on the skin. Similar results were obtained on apricot wounded and inoculated with three different concentrations (102, 103 and 104 conidia ml-1) of R. stolonifer. PAA and K-Sorb showed the same efficacy on apricots and nectarines against M. laxa. K-Sorb was less effective than PAA on nectarines and peaches inoculated with R. stolonifer. Fruit hydro-refrigeration significantly reduced the incidence of brown rot in Nero I and Van sweet cherries; disease control was improved by addition of PAA (125 mg L-1) in cold water. PAA efficacy on pre-existing infections can be very useful to control stone fruit diseases that can spread during shipping and marketing.

Nuclease Rsn from Rhizopus stolonifer catalyzes the hydrolysis of ss- and dsDNA in a ratio of approximately 2:1. Time course of 3 ′ and 5 ′ terminal analysis of the hydrolytic products of ss- and dsDNA showed that nuclease Rsn does not show any strict base preference and cleaves DNA in a non-specific manner. Moreover, separation of the hydrolytic products of ss- and dsDNA in the presence of Mg 2+ , Mn 2+ or Co 2+ showed the predominance of tetra-, tri-, and dinucleotides followed by mononucleotides, suggesting an endo mode of action.

The synthesis of new pyrazolo[3,4-b]pyrazines and related heterocycles has been reported. The key intermediate 1,6-diphenyl-3-methyl-1H-pyrazolo[3,4-b]pyrazine-5-carbonitrile 2 was obtained in one pot synthesis from the reaction of 5-amino-3-methyl-4-nitroso-1-phenylpyrazole 1 with benzoylacetonitrile. Modest antifungal activity was shown for some of the prepared compounds.

Invasive pulmonary mycosis caused by Aspergillus niger and Rhizopus stolonifer is reported in a 2-year-old horse, one of three that died after being housed in a disused, uncleaned stable. Lesions were characterized by thrombosis of the blood vessels with haemorrhage and tissue necrosis. Fungal hyphae were observed both in thrombosed vessels and in adjacent necrotic tissue. In culture media inoculated with lung samples and samples from the bedding hay, two types of colony were recorded and identified as A. niger and R. stolonifer. This study is the first description of equine pulmonary mucormycosis and of A. niger as an aetiological agent in the horse.

Peanut pod wart is a new disease in Israel that causes ugly warts on the pod. The causal agent, Streptomyces sp., contaminates seed during mechanical cracking of pods. Low-volume application of 3% iodine dissolved in glacial acetic acid resulted in effective pod disinfection and reduced the surface pods microflora by 4 log orders, but this mixture causes eye irritation and has an unpleasant smell. A 4 s exposure of the pods to a butane-air flame at 740 °C eradicated the pathogen and even a 6 s exposure did not affect seed germination or yield. This physical treatment also reduced significantly the incidence of other seedborne fungi, e.g. Aspergillus niger and Rhizopus stolonifer, in the laboratory and in a large-scale field test. Flaming enables the treatment of large quantities of pods prior to cracking.

Many yeasts, including yeast-like fungi, were selectively isolated from fruits and vegetables. In several assays performed on strawberries, table grape berries and kiwifruit, the yeast-like fungus Aureobasidium pullulans L47 and the yeasts Candida vanderwaltii L60 and C. oleophila L66 were the most effective antagonists of Botrytis cinerea and Rhizopus stolonifer . Isolates L47 and L66 were utilized in trials on strawberries grown under plastic tunnels. They were applied at flowering (full bloom and late petal fall) and at fruit maturity (just before or after harvest). Isolate L47 was the most effective against both B. cinerea and R. stolonifer . Both antagonists were more active when applied at the flowering stage, with isolate L47 more effective than vinclozolin. The antagonist population was consistently high on flowers and developing fruits, and on cold-stored strawberries. Isolates L47 and L66 showed a low sensitivity towards some fungicides in culture and were able to grow at temperatures between those of cold storage and 33 °C. Competition for nutrients seems to be the main mode of action.

2,5-Dimethoxybenzoic (DMB) acid was tested as an antifungal compound to control the postharvest decay pathogens of strawberry fruits. The compound completely inhibited in vitro spore germination and mycelial growth of Botrytis cinerea and Rhizopus stolonifer at a concentration of 5 × 10 −3 M. The effect of DMB acid treatments on the decay of strawberry fruits, stored at 20°C or at 3°C plus a period of simulated shelf-life storage, was investigated. A marked reduction in decay development was observed when commercially harvested strawberries were dipped or sprayed with 10 −2 M DMB acid. Its practical use on berries under field conditions has been also tested. The best results were obtained when fruits were dipped for 1 minute in 10 −2 DMB acid in combination with 0.05% (v/v) Tween 20.

Endophytic bacteria were tested in the postharvest biocontrol of Monilinia laxa and Rhizopus stolonifer in stone fruits. Of a total of 122 strains of these sub-epidermis micro-organisms isolated from various horticultural sources (cucumber, eggplant, pepper, tomato, zucchini, apricot, peach and plum), approximately twenty showed greater than 90% control of the given pathogens. R. stolonifer appeared to be less susceptible than M. laxa to the endophytes. The influence of conidial concentration of M. laxa and of antagonist/pathogen contact time on the effectiveness of biocontrol were also evaluated.

A hot water dip at 50°C for 2 min was more effective than 1 KGy of gamma radiation in reducing Botrytis cinerea and Rhizopus stolonifer decay in inoculated light-red tomatoes. The combined hot water and radiation treatment acted synergistically on fungal development resulting in 1.7% and 10.0% infection by B. cinerea and R. stolonifer, respectively, after 5 days at 23°C compared with 67% and 100% infection in the non-treated controls. Under natural infection conditions, hot water dip followed by irradiation at 0.5 KGy totally eliminated decay by Alternaria alternata during 8 days at 23°C. All treatments caused more rapid fruit softening, with 20% soft fruit in the combined treated fruit compared with zero soft fruit in the non-treated control.

Part of tre work was carried out under the H.E.J. Institute Karachi-University of Sussex Link Scheme. We thank Professor Atta-ur-Rahman. Dr. D.R.M. Walton and the British Council for establishing this link. We also thank the Spanish Ministry of Education for a grant.

The relationship between the structure of the substrates and the action of the fungus Rhizopus nigricans has been studied in order to obtain, in the highest possible yield, 11-hydroxyl derivatives which were dehydrated to the “exo” position, hydroborated with 9-BBN and oxidized with RuH2(Ph3P)4 to give 11-R and 11-S-6-epi-dendroserin. In the course of the biotransformation processes, 8α-hydroxyl and 7α-hydroxyl derivatives were also obtained, as well as the oxidation of the hydroxyl groups at C-1, an unusual process with Rhizopus nigricans. We have proved that the eudesmanones are more easily hydroxylated at C-11 than the hydroxyeudesmane compounds.

Incubation of methyl ent-15-oxokaur-16-en-19-oate with Rhizopus stolonifer and Mucor plumbeus gave methyl ent-7β,11α-dihydroxy-15-oxokauran-19-oate and methyl ent-7β,16β-dihydroxy-15-oxokauran-19-oate, respectively.

Background Airborne fungi, a significant constituent of atmospheric bioaerosol, are well-known source of allergens and can cause allergic rhinitis and bronchial asthma in sensitive subjects. Rhizopus stolonifer, the filamentous fungus is a widely distributed thread-like Mucoralean mold. Commonly found on bread surfaces, it takes food and nutrients from the bread and causes damage to the surface where it lives. Although a significant exposure risk is assumable in indoor environment, the role of this fungus in provoking allergic symptoms in pre-sensitized individuals, however, was poorly investigated. We conducted this study to monitor airborne R. stolonifer and to evaluate its potential as an aeroallergen causing nasobronchial allergy in sensitized individuals. Methods Seasonal periodicity of R. stolonifer was studied for 2 years (March, 2009-Feb.11) by Andersen air sampler. The relationships between meteorological parameters and airborne R. stolonifer concentration were explored by linear regression models. The allergic potential of R. stolonifer extract was studied on 389 respiratory allergic patients by performing skin prick tests (SPT) and measuring the allergen-specific IgE levels in SPT positive patient's sera by Enzyme-linked Immunosorbent Assay. SDS-PAGE and immunoblotting with pooled patient sera were performed to identify its IgE-binding components. Results Airborne R. stolonifer concentration range was 4 to 47 CFU/m3 and reached the peak concentration in March. Relative humidity was found to be a significant predictor for occurrence of R. stolonifer in air. Positive skin reaction was observed in 105 patients (27%) including 10 (9.5%) showing markedly high (2+ to 3+) skin sensitization. Crude antigenic extract of R. stolonifer was resolved in 16 protein bands in the molecular weight range of 12 to 72 kDa on SDS-PAGE (12% gel). Three IgE-binding protein bands (17, 21and 67.12 kDa) were detected by immunoblot analysis. Conclusions Exposures to R. stolonifer in environments where it naturally occurs may confer risk of IgE-mediated sensitization in sensitive individuals.

In the absence of nutrients, Rhizopus nigricans transforms progesterone into a mixture of 11 alpha-hydroxy-4-androstene-3,17-dione and 11 alpha-hydroxy-1,4-adrostadiene-3,17-dione. The same mixture is obtained by the transformation of testosterone and its acetate.

Rhizopus stolonifer sporangiospores were harvested with and without contact with water. The wet-harvested spores differed from the dry-harvested spores in that they: (i) incorporated 14 CO 2 into both tricar☐ylic acid-soluble and -insoluble material; (ii) possessed polyribosomes; (iii) did not maintain viability during storage at room temperature; and (iv) gradually exhibited altered nutritional requirements for germination. Consequently, wet-harvested spores cannot be considered to be either native or dormant. Even brief (30 min) exposures to water during harvesting caused the spores to commence metabolic activity.

A survey of the storage rot diseases of Treculia africana was conducted in Imo State, Nigeria in 1985–86. The storage loss was about 15·2% during severe infection. Four types of microorganisms, namely Botryodiplodia theobromae, Rhizopus stolonifer, Aspergillus niger and yeasts, were consistently isolated from the rotten seeds. A. niger, B. theobromae and R. stolonifer were associated with about 90% of the total loss. This is the first report of the occurrence of these microorganisms associated with T. africana seeds in Nigeria. The ability of each to cause storage rot of seeds was established and the effect of temperature, pH and different carbon sources on growth of the organisms investigated.

Polyadenylic acid [poly(A)]segments and polyadenylate-containing [poly(A+)] RNAs were isolated from dormant and germinating sporangiospores of Rhizopus stolonifer . At all stages of germination the poly(A) segments (i) composed about 0.1% of the total RNA, (ii) averaged about 33 residues in length, and (iii) were attached to large heterodisperse RNA molecules. From this information and knowing the weight of RNA per spore, we estimated that each dormant spore contained about 6.6 × 10 5 molecules of poly(A+) RNA. Translation of the spore poly(A+) RNA in vitro revealed that at least some of these molecules were functional messenger RNAs and that they coded for the synthesis of many discrete polypeptides.