Studies on the Development of the Reproductive Organs of Caloglossa leprieurii (Mont.) J. Ag.

The cell of Caloglossa leprieurli is a polycaryon. The sexual thalli are usually dioecious. Its life cycle involves the alternation of three generations. In the reproductive season, the appearance of tetrasporophyte and female and male gametophyte shows evident difference. The tetrasporophyte is big and flat. The branches are sparse. Many small red spots, i.e. tetrasporogial groups, can be seen with the naked eyes in the upper part of the branch. The terminal part of the female gametophyte is a little twisted with thick branches. The cystocarps are spherical and most of them are located in ventral side of the upper branch points. The male gametophyte is smaller with less branches. Its terminal part is a little twisted with pale colour. The pit connections of the vegetative cells of every thallus are all well developed. The carpogonial branch consists of four cells. Generally, it is formed by the division of the pericentral cell. After fertilization of the carpogonium, an auxiliary cell is formed by the division of supporting cell. Usually five to seven, even more than ten young procarps can be formed at the apical part of the reproductive branch. The procarps often occur on consecutive segments of pericentral ceils. But among most of them only a carpogonium is fertilized and developes into cystocarp. When a carpogonium is fertilized, the other one on this branch usually cease further development. The spermatangia are formed on the lateral wing cells of both sides of the upper part midrib of a reproductive branch and distributed on both dorsal and ventral surfaces. A vegetative cell is divided into three cells in parallel to the surface of the thallus. The cortical cells under the two outer surfaces forms three to four permatangial mother cells. Each spermatangial mother cell divides into two to four spermatangia. After the sperm dispersal of the mature spermatangia, the spermatangial mother cells are still retained on both sides of the middle discoid cells.     

Chlorotetracycline-binding surface regions in gemmalings of Riella helicophylla (Bory et Mont.) Mont.

The unistratose thallus of the gemmaling of Riella helicophylla is divided into an apical growth lobe with the meristem, an intermediate pillar, and a basal rhizoidal lobe. This organization can be correlated with a distinct fluorescence pattern of wall and membrane after treatment with chlorotetracycline. Mature cells of the growth lobe are distinguished by two chlorotetracycline-binding surface regions (CSR) with a diameter of 6–12 μm in the middle of both outer cell surfaces. Meristematic cells are devoid of CSR. The same is true for cells of the pillar which elongate under low light intensity. Rhizoid initials have an enlarged CSR on the site where the rhizoidal tube will emerge, whereas the opposite cell surface lacks any chlorotetracycline fluorescence. With the beginning of the extension of the rhizoid, CSR remains as a ring around the base of the tube. Darkness, plasmolysis, and sulfhydryl reagents inhibit the fluorescence of CSR, whereas calcium antagonists in addition suppress the fluorescence of the rhizoids. Cytochemical methods demonstrate that sulfhydryl proteins and anionic polysaccharides are involved in adsorbing chlorotetracycline in this region. Surface electron-microscopic preparations reveal a local depression of the wall covered with amorphous material.     

Fusarium moniliforme Sheld. In Israel (Gibberella Fujikuroi (Saw.) Wollenw.)

In studies with 58–76 Israeli isolates and 5–9 foreign isolates ofF. moniliforme, growth in vitro on wheat and PDA was best at 24–30° C, with little growth at 6° C and none at 40° C. In the optimal temperature range, equal growth was made in light and darkness. F. moniliforme is widespread in agricultural soils in Israel, but in some 170 samples rarely exceeded about 5 % of the totalFusarium population.Of seventy-six Israeli and nine foreign isolates, seventy-four induced toxic reactions on rabbit skin. This is an unusually high proportion. The histological changes induced by such skin application are described.Inoculation tests were performed with eighty-three Israeli isolates from six field and five fruit crops, and with thirteen foreign isolates (including six from varieties ofF. moniliforme) on ten crop plants. Onions and all dicotyledonous plants tested were affected by a high proportion of the isolates, while wheat was not, and maize was little affected. There was therefore little pathogenic specialization among these isolates.The studies carried out in Israel onF. moniliforme as cause of the black heart disease of banana fruits and of fruit rots of avocado and citrus are reviewed.Morphological studies of all Israeli isolates and of those received from abroad, and a survey of the literature on the taxonomy of the Liseola section ofFusarium, have led to the following conclusion: The section should containF. moniliforme as its only species, andF. moniliforme var.anthophilum andF. moniliforme var.subglutinans as its only two varieties.From the present distribution ofF. moniliforme and its environmental relationships it is concluded that this fungus constitutes a potential danger to crops in warm countries to which irrigation is being introduced, and especially to dense plantation crops.

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Zusammenfassung In vitro Wachstum von 58–76 Isolierungen derF. moniliforme aus Israel und aus anderen Ländern, auf Weizenkörnern und PDA, war optimal bei 24–30° C; bei 6° C entwickelte sich der Pilz kaum, und bei 40° C überhaupt nicht. Bei den optimalen Temperaturen war das Wachstum in Licht und Dunkelheit gleich gut. F. moniliforme ist in den Agrarböden Isracls weit verbreitet, jedoch überschritt der Pilz in 170 Bodenproben nur selten 5 % der gesamtenFusarium Bevölkerung.Von 76 Isolierungen aus Israel und 9 aus dem Ausland erregten nicht weniger als 74 Isolierungen toxische Reaktionen als sie auf die Haut von Kaninchen aufgetragen wurden. Die histologischen Aenderungen, die durch solches Auftragen bewirkt werden, werden hier beschrieben.Infektionsversuche an 10 Agrarpflanzen wurden mit 83 Isolierungen aus Israel und 13 aus dem Ausland durchgeführt. Alle Dicotyledone sowie Zwiebeln wurden von vielen dieser Isolierungen befallen, dagegen wurde Mais selten und Weizen fast gar nicht befallen. Es konnte daher nur eine geringe pathologische Spezialisierung unter den Isolierungen vonF. moniliforme festgestellt werden.In Israel ausgeführte Forschungen überF. moniliforme als Erreger der Black Heart Fäule von Bananen Früchten und von Avokado- und Zitrusfruchtfäulen werden hier besprochen.Morphologische Studien an Isolierungen aus Israel und dem Ausland, und eine Literaturübersicht der Liseola Sektion führten zur folgenden Schlussfolgerung: Diese Sektion sollF. moniliforme als ihr einziges Spezies enthalten, undF. moniliforme var.anthophilum sowieF. moniliforme var.subglutinans sind als Varietäten anzuerkennen.Die gegenwärtige Verbreitung vonF. moniliforme und seine Umweltsbeziehungen lassen darauf schliessen, dass dieser Pilz in warmen Ländern in denen Bewasserung eingeführt wird, eine Gefahr für verschiedene Agrarplfanzen, insbesondere dichte Pflanzungen, darstellt.

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The support given this study by the Central Research Fund of the Hebrew University is gratefully acknowledged.     

Comparative study of mycelia growth and sporophore yield of Auricularia polytricha (Mont.) Sacc on selected palm oil wastes as fruiting substrate

The potential for using agricultural and industrial by-products as substrate for the production of the edible mushroom, Auricularia polytricha, was evaluated using several formulations of selected palm oil wastes mixed with sawdust and further supplemented with selected nitrogen sources. The best substrate formulations were sawdust (SD) mixed with oil palm frond (OPF; 90:10) added with 15 % spent grain (SG) and sawdust mixed with empty fruit bunch (EFB; 50:50) added with 10 % spent grain (SG) with mycelia growth rate of 8 mm/day and 7 mm/day respectively. These two substrate formulations were then subjected to different moisture content levels (65 %, 75 % and 85 %). Highest total fresh sporophore yield at 0.43 % was obtained on SD?+?OPF (90:10)?+?15 % SG at 85 % moisture content, followed closely by SD?+?EFB (50:50)?+?10 % SG with 0.40 % total yield, also at 85 % moisture content. Each of the substrate formulations at 85 % moisture content gave the highest biological efficiency (BE) at 288.9 % and 260.7 %, respectively. Both yield and biological efficiency of A. polytricha on these two formulations were almost three times higher when compared to sawdust substrate alone, thus proving the potential of these formulations to improve yield of this mushroom.     

Studies on a strain of Fusarium solani (Mart.) Sacc. Isolated from a case of mycotic keratitis

A strain of Fusarium solani (Mart.) Sacc. (IMI-216517), isolated from a patient of mycotic keratitis, produced experimental keratomycosis in albino rabbit cornea and survived in internal tissues of albino mice for varying periods. Alantolactone, isolated from the plant — Inula racemosa Hook. f. exhibited marked in vitro fungistatic activity against this strain of F. solani at 100–200 g/ml concentrations. The strain was less sensitive to amphotericin B and showed more acid than alkaline proteinase and phosphatase activities.Communication No. 2526.     

Beobachtungen anCordyceps sinensis (Berk.) Sacc. und verwandten Pilzen

Ohne Zusammenfassung     

Ligase-Defective Bacteriophage T4 II. Physiological Studies

The timing of the suppression of gene 30 (deoxyribonucleic acid ligase) mutations by rII mutations was studied by temperature shift-down experiments with a temperature-sensitive rII mutation. The rII function must remain inactivated for about 5 to 8 min at 37 C for suppression to occur, thus making suppression an early function. This result is in agreement with the timing of expression of other rII functions. A gene 30 defect can also be overcome by replacing the Na(+) cation in the growth medium with the Mg(2+) cation, a result similar to the relief of the lethality of rII mutations in lambda lysogens. Prior infection with bacteriophages T3 or T7, which produce their own deoxyribonucleic acid ligases, can also partially overcome the lethality of gene 30 mutations.     

Rasterelektronenmikroskopische Untersuchungen anScopulariopsis brevicaulis (Sacc.)Bain. (Fungi imperfecti)

Summary Scanning photos of the imperfect fungusScopulariopsis brevicaulis (Sacc.)Bain. show new aspects of ontogenesis and morphology in this organism. Young conidia have a soft, deformable wall. Along fine spiral striations lateron the definite perisporal sculptures are formed.     

Meristem differentiation in Riella helicophylla (Bory et Mont.) Mont. under the influence of auxin or antiauxin

During the development of the unistratose gemmae of Riella helicophylla, the single intercalary meristem of the very young gemmae is subdivided into two lateral meristems. The duration of the cell reproduction cycle increases from the margin to the median part of the gemmae. This polarization within the meristem disappears after addition of the antiauxin PCIB to the culture medium. PCIB leads to a retardation or blockage of the cell cycle during the light period of the culture. Under the influence of PCIB the amount of starch in the chloroplasts is strikingly increased, probably because of a reduction of starch degradation. Addition of sugars compensates the effect of PCIB on the cell cycle. The effects of PCIB are counteracted by auxin. The results are taken as evidence that auxin plays a role in directing the transport of substances needed for the continuation of the cell reproduction cycle between adjacent cells of the meristem.Abbreviations IAA indole-3-acetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - PCIB p-chlorophenoxyisobutyric acid - G-l-P glucose-l-phosphat - EDTA ethylenediaminetetraacetic acid     

Weitere Untersuchungen zur Resistenz vonMedicago-arten gegenPseudopeziza medicaginis (Lib.) Sacc.

Zusammenfassung Durch Infektionsversuche an 44Medicago-Arten und-Varietäten mit den f. sp.medicaginis sativae undmedicaginis lupulinae vonPseudopeziza medicaginis sowie mitP. meliloti wurden die Kenntnisse über das Resistanzverhalten der GattungMedicago erweitert und frühere Ergebnisse bestätigt.

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Further investigations on the resistance ofMedicago species toPseudopeziza medicaginis (Lib.) Sacc.

Summary Experimental infections of 44 species and varieties ofMedicago with the f. sp.medicaginis sativae andmedicaginis lupulinae fromPseudopeziza medicaginis and withP. meliloti have broadened the knowledge on resistance behavior of the genusMedicago and confirmed earlier results.

     

Fungal Parasites of the Phytoplankton. II (Studies on British Chytrids, XII)

This paper brings together the species of Chytrid fungi recordedfrom large bodies of water in the British Isles. Four new speciesare described.     

Metabolic activities of the sugarbeet pathogens Fusarium solani (Mart.) Sacc. and Sclerotium rolfsii Sacc. under pyramin stress

Effects of different concentrations of active ingredient of the herbicide pyramin on metabolic activities of Fusarium solani and Sclerotium rolfsii were examined. High concentrations of this herbicide (1000 and 2000 g mL^-1 for F. solani and 100 and 200 g mL^-1 for S. rolfsii) had inhibitory effects on the metabolic activities of both fungi. These were demonstrated by significant decreases in growth, and increases in rates of CO₂ evolved, O₂ consumed and keto acids produced. These were accompanied by increased rates of sugar, nitrate and inorganic phosphorus absorption as well as lowered rates of synthesis of carbohydrates and insoluble nitrogenous (including protein) and phosphorus (including RNA-P and DNA-P) compounds. In addition, rates of excretion of both nitrogen and phosphorus fractions by the mycelial mats were increased.A concentration of 25 g mL^-1 exerted little or no effect on the metabolic activities of these fungi, although S. rolfsii was somewhat sensitive to this concentration.