THE SPECIES OF CIBORINIA PATHOGENIC TO SALIX,MAGNOLIA, AND QUERCUS

Batra , Lekh R. (Swarthmore Coll., Swarthmore, Pennsylvania.) The species of Ciborinia pathogenic to Salix, Magnolia, and Quercus. Amer. Jour. Bot. 47(10): 819–827. Illus. 1960.—There are 2 species of Ciborinia that attack various species of Salix. One of these, C. wisconsinensis, is reported as new and its phytopathology and life history are discussed. This species forms sclerotia in the leaves along the midrib. The sclerotia germinate in the year following infection and form apothecia in late June. In culture, sclerotia formed from mass ascospore-shootings produce apothecia. Ciborinia candolleana is reported for the first time attacking Quercus spp. in the United States. A key to the known species of the genus Ciborinia is provided.     

Non-gramineous hosts ofMyriosclerotinia borealis

On the basis of cultural, anatomical, and electrophoretic studies,Myriosclerotinia borealis (=Sclerotinia borealis) is shown to occur on cultivated non-gramineous plants includingIris ensata var.hortensis (Japanese iris),I. pseudoacorus, I. hollandica (Dutch iris), Perko PVH (a hybrid green manure crop betweenBrassica campestris andB. chinensis), Allium fistulosum, andCampanula portenshlagiana. The fungus did not kill these plants, but produced functional sclerotia, capable of carpogenic germination, on decayed leaves or necrotic lesions of overwintered leaves. The fungus seems to act as a saprophyte colonizing senescent leaves and/or as a weak parasite on plants injured by freezing during winter. In culture, the fungus produces discrete tuberoid sclerotia closely attached to the agar surface; rind differentiation is poor on the under surface of sclerotia. Medullary cells are embedded in a gelatinous matrix showing no distinct intercellular spaces. The ectal excipulum of apothecia produced under artificial conditions is composed of globose cells.Myriosclerotinia borealis is thus shown to be very close toCiborinia on the basis of these sclerotial and apothecial characters.     

Ciborinia gentianae sp. nov., the causal organism of sclerotial flower blight of cut-flower gentians

A new Ciborinia causing sclerotial flower blight of cut-flower gentians (Gentiana triflora var. japonica and interspecific hybrids between related species or varieties) is described as Ciborinia gentianae on the morphological basis of sclerotia and apothecia. The characteristics of Ciborinia gentianae are (1) an abundant production of spermodochia in the hollow cavity of host stems; (2) flat and thin sclerotia produced beneath the epidermis and the inclusion of host vascular remnants within their medulla; (3) globose cells composed of ectal excipulum of apothecia; (4) elongated cells with a slight apical swelling in ectal excipulum at the apothecial margin; and (5) tetra nucleate ascospores. Asci and ascospores mounted in Melzer's reagent measured 156–208 × 8–12 μm and 11.8–15 × 5.5–7.1 μm, respectively.     

桑椹肥大性菌核病病原菌生物学特性及流行性

【目的】对桑椹灾害性真菌病害——桑椹肥大性菌核病病原菌,即桑实杯盘菌(Ciboria shiraiana)的生物学特性进行研究,分析其流行性。【方法】采用人工接种、调查等研究方法,对C.shiraiana在无性生长阶段中菌丝侵染能力,菌核的休眠期,有性生长阶段中子囊孢子的结构、释放、数目以及萌发等进行研究,并对菌核萌发的物候期进行调查。【结果】C.shiraiana菌丝对桑雌花没有侵染能力;C.shiraiana菌核具有休眠期,低温处理6周以上的菌核才能萌发形成子囊盘;1个菌核可萌发1–15个子囊盘,直径为1.5 cm的子囊盘能产生高达(5.6–6.3)×10~7个子囊孢子;C.shiraiana子囊孢子在酸性环境中的萌发率明显高于在中性和碱性环境中的萌发率;C.shiraiana菌核萌发形成子囊盘产生子囊孢子的物候期,从1月下旬开始到4月中旬结束,其中在3月中旬萌发子囊盘的数目达到最高值。【结论】桑椹肥大性菌核病属于典型的流行性侵染病,在果桑栽培上容易造成毁灭性危害,生产上必须高度重视该病的防控。     

Sclerotinia trillii, sp. nov., causing a new sclerotinia disease onTrillium in Japan

Sclerotinia trillii n. sp., which attacksTrillium tschonoskii andT. smallii in Hokkaido and northern Honshu, Japan, is described. The characters identifying this species with the genusSclerotinia are large tuberoid sclerotia, produced both on infected plants and in culture, which consisted of only mycelium (true sclerotia) and flesh apothecia produced on them. This species is distinguished fromS. sclerotiorum, S. minor, S. trifoliorum, andS. nivalis by relatively large sclerotia, cultural colony appearance, and red-brown to yellow-brown, relatively large apothecium, in addition to its parasitic nature onTrillium. Sclerotinia trillii is a psychrophilic having an optimum temperature for mycelial growth at 15–20°C.     

Sclerotinia nivalis, sp. nov., the pathogen of snow mold of herbaceous dicots in Northern Japan

A newSclerotinia, previously reported asS. intermedia from Japan, is described asSclerotinia nivalis on the morphological basis of the sclerotial anamorph and teleomorph produced in culture. The characters assigning this species to the genusSclerotinia are the tuberoid sclerotia superficially produced on suscepts, the small sclerotia produced on aerial mycelium in culture, the interhyphal spaces in medullary tissue of sclerotia, and the globose cells constructing the ectal excipulum of apothecia. It is distinguishable fromS. sclerotiorum, S. minor, andS. trifoliorum by the intermediate sized sclerotia in culture, binucleate ascospores, the molecular mass of major proteins of sclerotia, and the patterns of esterase isozymes in sclerotial extracts. AlthoughS. nivalis causes snow mold of various dicots, it is a mesophile having an optimum temperature for mycelial growth of around 20°C. It attacks edible burdock(Arctium lappa), Chryhsanthemum morifolium, Ambrosia elatior, carrot(Daucus carota), Angelica acutiloba, Ajuga reptans, andPlantago lanceolata.     

Carpogenic Germination of Sclerotia of Sclerotinia sclerotiorum after Periods of Conditioning in Soil

Periods of conditioning in soil reduced the length of the resting period needed before sclerotia of Sclerotinia sclerotiorum could germinate to form apothecia. Curves for germination of sclerotia were fitted by a form of the log-logistic equation and from this equation the time taken for 50% germination (x₅₀) was calculated. These x₅₀ values were used as the basis for comparing germinability of sclerotia collected from infected sunflower plants and others conditioned in soil, or moist vermiculite for various times. Sclerotia from sunflower roots germinated sooner than those from the stem cavities. Germinability increased with the length of the conditioning period. Conditioning in soil was more effective than in moist vermiculite.     

Bacillus thuringiensis C25 suppresses popcorn disease caused by Ciboria shiraiana in mulberry (Morus australis L.)

The mulberry tree is an important crop for silkworm farming and for the health care industry. In Asia, the annual productivity of mulberry fruits is greatly reduced due to popcorn disease mainly caused by Ciboria shiraiana, a sclerotia-forming fungal pathogen. To date, the development of efficient biocontrol agents (BCAs) against this disease has been hampered by the recalcitrance of C. shiraiana to in vitro culturing methods. Here, we established alternative in vitro antifungal assays that directly monitored the effects of BCAs on the growth of C. shiraiana apothecia and further reported that Bacillus thuringiensis C25 suppressed popcorn disease in field conditions. Initially, from mulberry drupelets showing the popcorn disease symptoms, we confirmed the infection of C. shiraiana and observed its morphology in asexual stage. Then, apothecia of C. shiraiana were induced from the sclerotia collected from the disease-infested orchard. Two bacterial isolates, Enterobacter sp. C5 and B. thuringiensis C25, strongly suppressed the elongation and fresh weight accumulation of apothecia stalks, the width of hymenium, and ascus and ascospore formation of C. shiraiana. In addition, both bacterial isolates degraded the ultrastructure of hymenium cells in C. shiraiana apothecia. Ultimately, treatment of mulberry trees with B. thuringiensis C25 mitigated the incidence of popcorn mulberry disease under field conditions. In conclusion, B. thuringiensis C25 is the first reported BCA shown to efficiently control mulberry popcorn disease. Our results also support that B. thuringiensis exerts diverse biocontrol roles in addition to insecticidal behaviour.     

A synopsis of the genusScleromitrula (=Verpatinia) (Ascomycotina: Helotiales: Sclerotiniaceae)

The systematics ofScleromitrula andVerpatinia of the family Sclerotiniaceae is reevaluated on the basis of morphological, cultural and molecular criteria.Scleromitrula shiraiana, Verpatinia species andCiborinia candolleana share gross morphological, microanatomical and cultural features which clearly distinguish them from the closely relatedCiborinia andRutstroemia species. Phylogenetic analyses of sequences from the internal transcribed spacer region (ITS1, ITS2, and the 5.8S gene) of nuclear ribosomal DNA demonstrate that the stipitate-capitate specimens ofScleromitrula andVerpatinia species plus the stipitate-cupulateCiborinia candolleana constitute a monophyletic clade separate from a clade including the type species ofCiborinia. Scleromitrula is emended to includeS. shiraiana, the new speciesS. rubicola, C. candolleana, and specimens formerly assigned toVerpatinia. A key to the accepted species ofScleromitrula is provided.     

<Emphasis Type="Italic">Endohyalina</Emphasis>, the genus in the Physciaceae to accommodate the species of the <Emphasis Type="Italic">Rinodina ericina-</Emphasis>group

The genus Endohyalina is characterized by crustose, autonomous, or obligately lichenicolous thalli, lecideine apothecia with a hymenium often more or less inspersed with oil droplets and a brown hypothecium, Bacidia-type asci, small Dirinaria-type ascospores developing with type B ontogeny, bacilliform conidia and containing diploicin as the major secondary metabolite. The genus is based on four species previously included in Rinodina—R. ericina s. lat., R. insularis, R. interjecta and R. kalbii—and on two lichenicolous species from the Canary Islands described here as new, Endohyalina brandii and E. diederichii. The generic type, Endohyalina rappii, is reduced to synonymy with E. ericina whereas E. circumpallida is excluded from the genus and returned to Buellia s. lat. Except for the thalline growth form and the common lichenicolous habit, the diagnostic characters of Endohyalina are akin to those of Diploicia. New chemical data on Endohyalina insularis and E. kalbii are reported, and a simple method for determining the secondary chemistry of lichenicolous fungi is provided.     

Use of Coniothyrium minitans and other microorganisms for reducing Sclerotinia sclerotiorum

Biological control agents (BCAs) Bacillus subtilis QST 713, Coniothyrium minitans CON/M/91-08, Streptomyces lydicus WYEC 108, and Trichoderma harzianum T-22 were evaluated for their efficacy in the reduction of survival of sclerotia and production of apothecia of Sclerotinia sclerotiorum under controlled environments. A growth chamber assay was conducted where 25 sclerotia were buried in pots containing potting soil, and BCAs were drenched into the soil at various concentrations, and five soybean seeds were planted in each pot. The presence and number of S. sclerotiorum apothecia were recorded daily. Sclerotinia sclerotiorum sclerotia were retrieved six weeks after seeding and viability was assessed on water agar plates. All BCAs were effective in reducing S. sclerotiorum inoculum at various efficacies. In general, efficacy was positively correlated with the rate of application. At the rate of application when the efficacy did not change significantly by increasing the rate, the BCAs had various reductions of apothecia and sclerotia. B. subtilis reduced apothecia and sclerotia by 91.2 and 29.6%, respectively; C. minitans reduced apothecia and sclerotia by 81.2 and 50%, respectively; Streptomyces lydicus reduced apothecia and sclerotia by 100 and 29.6%, respectively; Trichoderma harzianum reduced apothecia and sclerotia by 80.5 and 31.7%, respectively. In addition, the commercial strain of C. minitans CON/M/91-08, and a wild Michigan strain of C. minitans W09 were compared for their growth and sclerotial reduction. W09 had faster growth rate than the commercial strain, indicating potential diversities of biological control strains to be studied.     

Caloplaca erodens [sect. Pyrenodesmia], a new lichen species from Italy with an unusual thallus type

Caloplaca erodens is a new species of sect. Pyrenodesmia, characterised by an orbicular, sorediate, bluish-grey thallus which is endolithic but emerges at the periphery with a white, K−, obscurely lobate prothallus. The species is frequent on calcareous outcrops and walls of isolated churches and ruins of the Central Apennines (Sibillini, Gran Sasso), where it may occur in large monospecific populations, from 1000 to 2500 m asl., and is also known from dry sites of the southern Alps. It has been found with apothecia only in the type locality, being predominantly sterile. The reproduction of this lichen is evidently linked to the release of fragments of clusters of photobiont cells and mycobiont hyphae which are continuously exposed with the dissolution of the substratum. Readily distinguished from the apparently similar endolithic C. alociza (which is characterised by numerous apothecia, black, K+ purple prothallus, and esorediate thallus), C. erodens probably belongs to the C. circumalbata complex, whose taxa are always epilithic but have a white, K− prothallus. The phylogenetic position of the new species within sect. Pyrenodesmia as inferred by ITS sequences of the nuclear ribosomal DNA is shortly discussed.     

Dematiaceous fungal pathogens isolated from nature

This study was conducted to demonstrate the presence of pathogenic dematiaceous fungi in nature. Using hamster and mouse inoculation techniques, 43 isolates of dematiaceous fungi were recovered from 39 samples of woody plant material and soil from the Virginia environment. Thirteen species were identified and included 4 Phialophora spp., 3 Cladosporium spp., 2 Exophiala spp., Sporothrix sp., Wangiella dermatitidis, Bispora betulina, and Scytalidium lignicola. Evidence is presented for the first isolations of C. trichoides from nature in the United States; these isolates proved to be pathogenic for mice in which they produced disease and death in a course similar to that seen in man. Natural isolates of Phialophora verrucosa, Phialophora repens, Exophiala jeanselmei, and Wangiella dermatitidis were identical to those species isolated from man using the following criteria: morphology, 12% gelatin reaction, and survival in laboratory animals.     

Kohninia linnaeicola, a new genus and species of the Sclerotiniaceae pathogenic to Linnaea borealis

A new genus and species is described to accommodate a newly discovered fungus pathogenic to Linnaea borealis. The fungus forms true sclerotia on stems and leaves of its host and apothecia arise singly or gregariously on the surface of ripe sclerotia. The new fungus was collected together with a stromatic conidiomal fungus that occurred on the same host. A putative teleomorph-anamorph connection of the observed taxa was ruled out by sequence comparison of the nuclear ribosomal internal transcribed spacer DNA sequences (ITS rDNA). Based on morphology and pathogenicity, the new fungus belongs in the family Sclerotiniaceae, Helotiales, Ascomycota. A phylogenetic analysis of ITS rDNA sequences from 26 taxa of the family Sclerotiniaceae was performed to conclude on the systematic position of the new fungus. The small tuberoid sclerotia, brownish subsessile to substipitate apothecia, four-spored asci, ellipsoid to isthmoid ascospores, inability to grow on PDA culture media and a number of ITS rDNA sequence autapomorphies characterize and distinguish the fungus from other taxa of the Sclerotiniaceae.     

中国异极衣科地衣二新记录种

该文综合运用形态学、解剖学和化学等方法对山东大型地衣进行分类研究,发现了两个中国新记录种,即德氏蜂窝衣(Heppia despreauxii)和多孢小极衣(Lichinella myriospora).德氏蜂窝衣隶属于蜂窝衣属(Heppia),生于光线充足且裸露的土壤上,主要识别特征为下皮层缺失、子实层IKI+蓝色;多...     

Decay of Sclerotia of Botrytis cinerea by Trichoderma spp. at Low Temperatures

In vitro, tests were conducted at 10°C and 5°C against sclerotia of Botrytis cinerea with 58 isolates of Trichoderma spp., highly antagonistic at 24°C but differing in their cold tolerance. Some isolates macerated and colonized sclerotia even at 5 °C. With 19 isolates of Trichoderma spp. less than 10 % of the sclerotia remained viable after 42 d at 5 °C. Conidia ol some Trichoderma spp. germinated at 5 °C within a few days and reached germination rates higher than 80 %. It seems to be feasible to use selected isolates of Trichoderma spp. for biological control of sclerotia of ß. cinerea also during the colder season.     

植物病原真菌的菌核研究进展

真菌菌核是相关真菌在特殊环境下由营养体菌丝交织和聚集形成的具有抵御恶劣环境能力的休眠结构,在真菌生活史及病原真菌的病害循环中具有重要的生物学和生态学意义。许多引起严重植物病害的病原真菌能够形成菌核,这类真菌通过菌核度过逆境。菌核在适宜条件下萌发形成子囊盘和孢子或菌丝,造成植物的侵染。本文从形成菌核的真菌种类、生物学特性、黑色素及分子生物学等方面进行综述,旨在为深入研究真菌菌核及其在真菌学、植物病理学及药用真菌学等领域应用提供研究思路和参考依据。     

Phyllopsora leprosa,eine neue Flechten-Species aus Surinam

Zusammenfassung Phyllopsora leprosa H.Riedl, sp. n., unterscheidet sich von allen anderen bisher bekannten Arten der Gattung durch den staubig-sorediös aufgelösten vegetativen Flechtenthallus und extrem kleine Apothezien, Asci und Sporen.

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Phyllopsora leprosa, a new lichen species from surinam

Summary Phyllopsora leprosa H.Riedl, sp. n., is distinct from all the other species of the genus hitherto known by its powdery vegetative lichen-thallus, and extremely small apothecia, asci and spores.

     

THE LABORATORY CULTIVATION OF PHYSARUM FLAVICOMUM

Gray , William D. (Ohio State U., Columbus.) The laboratory cultivation of Physarum flavicomum. Amer. Jour. Bot. 48(3): 242–243. 1961.—The laboratory cultivation of P. flavicomum on artificial medium is reported here for the first time. The plasmodium of this species can be easily cultivated on dry rolled oats in a moist chamber in the same manner as plasmodia of P. polycephalum, or on 3% rolled-oats agar. Plasmodia form sclerotia from which new cultures can later be started or they can be obtained by sowing spores on rolled oats agar. Like P. polycephalum, the plasmodia of P. flavicomum must be illuminated with visible light in order to induce the onset of the sporulating stage. Sporangia which develop in culture vary most noticeably with respect to the type of peridium. The nature of the peridium is largely determined by whether the sporangium develops under moist or dry conditions; dry conditions favor the formation of a lime-encrusted peridium, while humid conditions favor the development of a thin, limeless peridium which has a metallic luster.     

<Emphasis Type="Italic">Typhula maritima</Emphasis>, a new species of <Emphasis Type="Italic">Typhula</Emphasis> collected from coastal dunes in Hokkaido,northern Japan

Typhula maritima on coastal dunes in Ishikari and Yoichi, Hokkaido, northern Japan, is illustrated as a new species on the basis of morphology and molecular evidence. The sclerotia in the sand had mycelial strands that extended upward to support basidiocarps. Mycelial strands also connected sclerotia with plant tissues of the dunegrass Eylmus mollis Trin. Typhula maritima is psychrotrophic and halotrophic, and sclerotia floated on seawater for 1 week. These physiological characteristics are important factors for adaptation to the coastal dune environment. Inoculation tests indicated that T. maritima could grow on living E. mollis, but it was not pathogenic. The results suggested that this fungus was, at least, not an active pathogen in the coastal dune ecosystem. Ex-holotype is TH-AIST-Tm-1 (= NBRC 104266).