Longitudinal Septa Research Articles

First Report of Gray Leaf Spot Caused by Alternaria brassicae on Canola in Argentina

Canola (Brassica napus) is a developing oleaginous crop grown commercially in Argentina. During 2003, typical symptoms of a foliar disease were observed on canola plants in experimental field plots in Buenos Aires. Average disease incidence across 14 6-month-old canola cultivars was 27% (range 12 to 42%). Climatic conditions in Buenos Aires during August 2003 included moderate temperatures and periods with high humidity, which were apparently favorable for disease development. Symptoms were observed on leaves, stems, and pods. Leaf symptoms were randomly distributed on the adaxial surfaces and consisted of zonate lesions of alternating light gray and dark brown areas that were 6 to 10 mm in diameter. Remaining leaf tissue was chlorotic and affected leaves abscised. Stem infections appeared as irregular and elongated black lesions, 0.7 to 1.2 cm long. Pods lesions were circular, 6 to 8 mm in diameter, gray in the center, and surrounded by a diffuse dark brown margin. The disease developed progressively from the lower leaves to the pods, resulting in premature senescence of the tissues, chlorosis, and defoliation. Conidiophores bearing conidia colonized the lesions as a dark gray growth of spore masses. Segments (0.5 cm long) taken from leaves, stems, and pods of diseased plants were dipped in 70% ethanol, surface sterilized with NaOCl (1%) for 2 min, and rinsed in sterile water. Each segment was blotted dry and placed on potato dextrose agar. Plates were incubated in the dark at 25°C for 2 to 3 days, followed by incubation under NUV light and a 12-h light/dark photoperiod for 6 to 8 days. Six fungal isolates were obtained. Fungal colonies were pale gray with dark concentric rings. Conidia were yellow to pale brown, ellipsoid to ovoid, produced singly or in short chains, with 8 to 10 transverse septa and 2 to 6 longitudinal septa. The spore body measured 13 to 22 × 68 to 135 µm with a beak cell 42 to 101 µm long. On the basis of conidial and cultural characteristics, the fungus was identified as Alternaria brassicae (Berk.) Sacc (1). Koch's postulates were completed for three isolates by spray-inoculating foliage of 6-week-old canola plants of cvs. Caviar, Dunkeld, Eclipse, Impulse, Mistral, and Sponsor with a conidial suspension (1 × 105 conidia per ml). The experiment, which included four inoculated plants and two noninoculated control plants for each cultivar per isolate, was conducted in the greenhouse at 22 to 24°C and maintained at 75% relative humidity with no supplemental light. Inoculated and control plants were covered with polyethylene bags for 48 h after inoculation. Within 12 days, inoculated plants developed small, brown lesions on leaves and stems for all three isolates; the pathogen was successfully reisolated in all instances. Control plants, inoculated only with sterile distilled water, remained symptomless. The experiment was repeated with similar results. The results suggest that A. brassicae may be a threat to the main cultivars being grown in Argentina. To our knowledge, this is the first report of A. brassicae causing gray leaf spot of canola in Argentina. Reference: (1) J. Joly. Le genre Alternaria. Recherches Physiologiques, Biologiques, et Systématiques. Paul Lechevalier, ed. Paris, France, 1964.

First Report of Alternaria Leaf Blight of Aralia japonica Caused by Alternaria panax in Europe.

Aralia japonica (synonym Fatsia japonica), belonging to the Araliaceae family, is a foliage plant highly valued in Italy for landscape and interior decoration. In the fall of 2002, a leaf blight disease was observed on plants grown in pots that were maintained under shade at a density of 15 to 20 pots per m2 at a nursery located in central Italy (Teramo Province). Typical symptoms were tan-to-dark brown leaf spots and rapid blighting of foliage under moist conditions. Chlorotic zones around necrotic lesions were common, and considerable leaf drop was associated with the disease. Affected plants were rarely killed, but the presence of lesions on mature plants reduced aesthetic quality and market value. The disease occurred on 70% of the plants. A fungus identified morphologically as Alternaria panax (2) was consistently isolated from infected leaves on potato dextrose agar (PDA). The fungus grows slowly and sparsely on PDA and produces a light brown mycelium, a characteristic red diffusible pigment in the agar medium, and rare conidia under 12-hr photoperiods. Measurements were carried out on conidia formed from single-spore isolates grown on autoclavated host tissue on water agar (LWA) at 24°C for 10 days. In LWA culture, conidia were borne singly or in chains of two to four conidia. Conidia produced in culture were smaller than those formed on the host and were highly variable in shape. They appeared obclavate, ellipsoidal, and obpyriform and pale to dark brown with relatively short or false beaks. Conidial bodies were 14.4 to 48.0 μm long (average 30.5 μm) and 7.2 to 12.0 μm wide (average 9.9 μm) with 3 to 10 transverse and a few longitudinal septa. Length of appendages was 9.6 to 26.0 μm (average 16.0 μm). Pathogenicity tests were performed by inoculating leaves of healthy Aralia japonica and Schefflera actinophylla plants by placing mycelial disks (5 mm in diameter) directly on wounded leaf tissues. Uninoculated, wounded plants served as controls. Four plants of each species were used. Plants were covered for 72 h with plastic bags and maintained in a growth chamber at 20°C (12 hours per day of fluorescent light). Control plants were maintained similarly. The first lesions developed on leaves of inoculated plants of both species after 7 days. A. panax was consistently reisolated from the lesions. The pathogenicity test was carried out twice. The presence of A. panax on Aralia japonica has been reported in Japan, Korea (2), and the United States (1) but to our knowledge, this is the first report of A. panax on Aralia japonica in Europe.

Scanning electron microscopy of Aspidogaster ijimai Kawamura, 1913 and A. conchicola Baer, 1827 (Aspidogastrea, Aspidogastridae) with reference to their fish definitive-host specificity.

Two species of aspidogastreans, namely Aspidogaster ijimai and A. conchicola, were studied by scanning electron microscopy. In nine lakes and an old river course, the Tian'ezhou oxbow, investigated in the flood plain of the Yangtze River, A. ijimai was obtained from the common carp ( Cyprinus carpio) in three lakes, and A. conchicola from the black carp Mylopharyngodon piceus in three lakes and the oxbow. In none of the localities, however, were the two species found together. It is suggested that A. ijimai may be considered as a specialist parasite for the common carp, at least in the flood-plain lakes of the Yangtze River. The two parasites were similar in many aspects of their morphology. Their bodies can both be separated into a dorsal part and a ventral disc, with the body surface of the dorsal part elevated by transverse folds, and the disc subdivided into alveoli by transverse and longitudinal septa, although the number of alveoli was different in the two species. The depression on the ventral surface of the neck region was prominent for both species, and their ventral disc was covered densely with non-ciliated bulbous papillae. The position of mouth, osmo-regulatory pore and marginal organ was also similar for A. ijimai and A. conchicola. However, microridges in the trough of the folds in the neck region and numerous small pits on the upper part of the septa were found exclusively in A. ijimai, but uniciliated sensory papillae in A. conchicola.

Alternaria carthami와 A. alternata에 의한 잇꽃 잎점무늬병

잇꽃 잎점무늬병이 2000년 경북 의성군 일대의 잇꽃재배농가포장에서 발생하였다. 조사지역의 발병엽율은 30% 내외였다. 병징은 발아 후에 떡잎에 갈색의 반점을 만들어 완전히 전개하지 못하여 갈변하여 갈라지는 증상과 생육중기이후 잎에 갈색의 반점과 주위에 노랗게 탈색되는 병징이 생기고 이후 중앙부위는 회색 또는 검은 색으로 확대되면서 주위의 노란 변색부위도 확대되었고, 심해지면 전체가 갈색으로 고사하여 낙엽 되었다. Alternaria alternata의 균학적 특징은 분생자경의 길이는 20~110<TEX>${\mu}m$</TEX>; 포자의 크기가 10~20 <TEX>${\times}$</TEX> 30~60 <TEX>${\mu}m$</TEX>이었으며, 격벽수는 3~8개; beak의 길이는 5~35 <TEX>${\mu}m$</TEX>로 짧은 형태의 포자가 연쇄상으로 붙어 있었다. A.carthami는 분생자경의 길이는 40~80<TEX>${\mu}m$</TEX>; 포자의 크기가 10~15 <TEX>${\times}$</TEX>40~100 <TEX>${\mu}m$</TEX> 이었으며, 격벽수는 4~10개; beak의 길이는 30~65 <TEX>${\mu}m$</TEX>로 대부분의 포자는 하나씩 분리되어 있었다. 잇꽃의 점무늬 병징에서 분리한 병원균의 균학적 특징을 Joseph(1994)의 보고와 비교해본 결과 생육중기에 분리된 균은 A. carthami이었으며, 떡잎과 노쇄한 잎의 병반에서 분리한 병원균은 A. alternata로 동정되었다. 그러므로 이 병을 A. carthami와 A. alternata에 의한 잇꽃의 잎점무늬병으로 명명할 것을 제안한다. Leaf spot diseases were found on safflower (Carthamus thinctorius) leaf in several fields located in Euisong-Gun, Gyengbuk province in Korea. The infected leaf rate of the diseases in surveyed area were different each years from 2001 to 2003 such as about 5%, 10%, and 30%, repectively. The typicla symptoms of diseases appeared first as small, light brown spots on leaves. And then spot turn dark brown and magnified. And yellow decoloration zone appeared surrounding dark brown spots. Mycological characteristics of Alternaria carthami, isolated from safflower mature leaf spot were dark gray colonies, conidiophores simple erect, septated, 40~80 <TEX>${\mu}m$</TEX> length; conidia solitary, straight, body size fo without beak length 40~100<TEX>${\mu}m$</TEX>, 10~15<TEX>${\mu}m$</TEX> thick, Number of transverse septa 4~10 and longitudinal septa 4~7 ; beak with 2~4 septa, 30~65<TEX>${\mu}m$</TEX> length. And A. alternata, isolated from old leaf were gray~dark gray colonies, conidiophores simple or branched, 20~110 <TEX>${\mu}m$</TEX> length; conidia long chaines, short conical or cylindrical beak, 2~6 transverse septa and several longitudinal septa, body size of without beak length 30~60 <TEX>${\mu}m$</TEX>, 10~20 <TEX>${\mu}m$</TEX> thick ; beak length 5~35 <TEX>${\mu}m$</TEX>. These are the first report on the leaf spot of safflower caused by Alternaria carthami, A alternata in Korea.

First Report of Bulb Canker of Garlic Caused by Embellisia allii in Korea

Embellisia allii causing bulb canker of white garlic (Allium sativum) has been observed on harvested or stored garlic bulbs. Identification of the fungus was determined based on the symptoms and morphological characteristics on in vitro potato dextrose agar (PDA) and malt extract agar (MEA). Colonies were effuse, blackish brown to black, velvety or powdery. Conidia were solitary, almost straight, most commonly ellipsoidal (or subcylindrical) to ovoid, mid to dark brown, smooth, with very dark 1 to 6 transverse (commonly 3~4) and occasionally 1 or 2 oblique or longitudinal septa, and 30.4×13.4 μm (av.). Conidiophores were simple or branched, straight or flexuous, up to 80 μm long and 5.1~10.2 μm thick. Chlamydospores were developed through enlargement and repeated cellular division of several adjacent hyphal cells to form a complex of thickwalled cells. The conidial measurements of garlic isolates closely matched the previous description of E. allii.

Achondrogenesis Type IB Agenesis of Cartilage Interterritorial Matrix as the Link Between Gene Defect and Pathological Skeletal Phenotype

Achondrogenesis type IB is a lethal osteochondrodysplasia caused by mutations in the diastrophic dysplasia sulfate transporter gene. How these mutations lead to the skeletal phenotype is not known. Histology of plastic-embedded skeletal fetal achondrogenesis type IB samples suggested that interterritorial epiphyseal cartilage matrix was selectively missing. Cartilage was organized in chondrons separated by cleft spaces; chondrocyte seriation, longitudinal septa, and, in turn, mineralized cartilaginous septa were absent. Agenesis of interterritorial matrix as the key histologic change was confirmed by immunohistology using specific markers of territorial and interterritorial matrix. Biglycan-enriched territorial matrix was preserved; decorin-enriched interterritorial areas were absent, although immunostaining was observed within chondrocytes. Thus, in achondrogenesis type IB: (1) a complex derangement in cartilage matrix assembly lies downstream of the deficient sulfate transporter activity; (2) the severely impaired decorin deposition participates in the changes in matrix organization with lack of development of normal interterritorial matrix; and (3) this change determines the lack of the necessary structural substrate for proper endochondral bone formation and explains the severe skeletal phenotype.

Two new species of Duplicibothrium Williams & Campbell, 1978 (Tetraphyllidea: Serendipidae) from the Pacific cownose ray Rhinoptera steindachneri.

Two new tetraphyllidean species, Duplicihothrium caircae n. sp. and D. paulum n. sp., are described from Pacific cownose rays Rhinoptera steindachneri collected from the Gulf of California. D. cairae n. sp. differs from the only other known species in this genus, D. minutum, in its possession of two posteriorly bifurcating longitudinal septa on each bothridium and having a greater number of loculi per bothridium, wider bothridia and a greater number of segments per worm. D. paulum n. sp. differs from the above two species in being shorter, having two continuous longitudinal septa on each bothridium, rather than posteriorly bifurcating or absent longitudinal septa, having a greater number of loculi per bothridium and having fewer segments per worm. The generic diagnosis of Duplicibothrium is amended to reflect the inclusion of the two new species. Species of Duplicibothrium appear to be restricted to host species of the genus Rhinoptera. Systematic information gained from the study of these two new species supports the monophyly of the tetraphyllidean family Serendipidae and suggests that Duplicibothrium shares a phylogenetic heritage with species in the genera Glyphobothrium and Serendip, taxa that are also parasitic in cownose rays. Evidence for a phylogenetic relationship between serendipid species and species of Dioecotaenia is discussed, as are potential molluscan hosts for cestode species in Duplicibothrium and Dioecotaenia.

First Occurrence of Alternaria alternata on Gypsophila paniculata in Bulgaria.

During late summer 1996 to 1997, 27 to 30% of Gypsophila paniculata (baby's-breath) plants were noted as diseased in an experimental field (Kazanlak, Bulgaria). Symptoms on lower and middle leaves consisted of small circular spots, with light brown centers and reddish purple margins. Development of numerous spots (which grew larger) and, especially, damage to the midrib led to withering of leaflets. Conidiophores of the isolated fungus were dark, formed singly or in clusters, were unbranched with three to eight septa, and were 40 to 120 µm long. Conidia, produced in branched chains (four to six conidia or longer), were brown, globose, and ovate to pyriform with short beaks, contained four to five transverse and zero to two longitudinal septa, and were 36.6 to 46.6 × 10.0 to 13.3 µm. The fungus was identified as Alternaria alternata. Pathogenicity was confirmed by artificial inoculation of potted G. paniculata and Dianthus caryophyllus plants. Conidia (2 weeks old) produced on potato dextrose agar were sprayed on plants in a 5 × 103 suspension, and plants were incubated at 20 to 24°C in a moist chamber for 2 days. Lesion development in both plant species was observed and recorded at 4 to 5 and 6 to 7 days after inoculation, respectively. Lesions were most numerous on G. paniculata. This is the first report of A. alternata on baby's-breath in Bulgaria.

Outbreak of Leaf Spot of Saponaria Caused by Alternaria saponariae in California.

Saponaria (Saponaria vaccaria [= Vaccaria hispanica]) is a Caryophyllaceae plant that is grown commercially in California as a cut flower. In 1998, a leaf spot disease devastated the commercially grown saponaria in coastal California. The entire saponaria crop was completely unmarketable because of extensive leaf spotting. Symptoms consisted of circular, brown, necrotic leaf spots with diameters up to 8 mm and concentric zones of lighter and darker tissue. Chlorotic borders developed around the spots. Conidia from leaves were obclavate, usually had 7 transverse and 1 to 4 longitudinal septa, and narrowed gradually toward the apex into a blunt-tipped, unbranched beak cell. The spore body measured 69 to 90 (to 119) × 17 to 21 (to 25) μm, with the distinctive beak cell 17 to 53 μm long. Conidia formed short chains on host tissue. The fungus was identified as Alternaria saponariae (Peck) Neergaard (2). For pathogenicity tests, six representative isolates were grown on V8 juice agar under fluorescent tube lighting. Potted saponaria were sprayed with either conidial concentrations (1 × 10e5 conidia per ml) or water. Plants were incubated in a chamber with a humidifier for 48 h and then maintained in a greenhouse (23 to 25°C). After 14 days, leaf spots similar to the original symptoms developed on all inoculated plants, and the pathogen was reisolated. Plants sprayed with water were symptomless. The experiment was repeated and the results were similar. Using the same isolates and method, we inoculated carnation (Dianthus caryophyllus), sweet William (Dianthus barbatus), and saponaria. However, disease developed only on saponaria. While A. saponariae on saponaria was reported previously in California (1), this is the first report to characterize the pathogen and document that isolates are pathogenic on saponaria but not on other commercial Caryophyllaceae hosts.

Intra-follicular visceral musculature in Omorgus freyi (HAAF) (Coleoptera: Trogidae) testes

The testicular follicles of the desert-adapted beetle Omorgus freyi (Haaf) (Coleoptera : Trogidae) are unusually large, relative to male size. The advance of the sperm-producing cells towards the efferent duct and, eventually, that of spermatozoa to the deferent duct, is apparently facilitated by the unique structure of these extended follicles. In contrast to the typical insect follicle, those of O. freyi and other scarabaeoid beetles have an internalized and elongated efferent duct. But, additionally, in O. freyi, the follicles are subdivided by longitudinal septa, radiating from the central efferent duct. A net of slow-supercontracting visceral muscles extends throughout the septa and efferent duct. We hypothesize that this unique structure is an adaptation maximizing reproductive potential by mobilizing large numbers of spermatozoa throughout the huge testes and transferring them to the female during the irregular short bouts of reproductive activity following the unpredictable rainfall.

Leaf Spot of Radicchio Caused by Alternaria cichorii in California.

A foliar disease of commercially grown radicchio (Cichorium intybus) was observed in 1996 and 1997 in the Salinas Valley (Monterey County), California. Symptoms consisted of circular to oblong, necrotic spots ranging in diameter from 3 to 20 mm and having concentric zones of darker tissue. A fungus identified as Alternaria cichorii Nattrass (1) was observed fruiting on the spots and was consistently isolated from the margins of the spots. Conidia from leaves were obclavate in shape with slender, unbranched beaks extending from the narrow end of the spore body. Spore body dimensions measured 56 to 78 × 14 to 20 μm, and beaks measured 36 to 81 × 1 to 2 μm. Spore bodies had 7 to 9 transverse septa. Often there were no longitudinal septa, but occasionally there were 1 or 2 such septa. For pathogenicity tests, five isolates were grown for 4 weeks on potato dextrose agar under a combination of cool white and Vita-Lite fluorescent tubes on a 12 h light/dark cycle. Conidial suspensions (4.0 × 104 conidia per ml) were sprayed onto 8-week-old radicchio (cv. Rossana Rogers). Plants were incubated in a moist chamber for 48 h and then maintained in a greenhouse. After 12 days, leaf spots similar to the original symptoms developed on all plants inoculated with the five isolates, and the pathogen was reisolated. Control plants sprayed with distilled water remained symptomless. The experiment was repeated and the results were similar. When inoculated onto endive (Cichorium endivia cv. Tres Fine Maraicchere) and two lettuce (Lactuca sativa) cultivars, the isolates caused small (1 to 2 mm in diameter), necrotic, circular leaf spots on endive and Romaine lettuce cv. Green Towers, but did not cause symptoms on the iceberg lettuce cv. Alpha. This is the first report of A. cichorii on commercially grown radicchio in California. In addition, the same disease was confirmed on commercially produced greenhouse transplants of radicchio, indicating that primary inoculum can possibly be seed-borne. Reference: (1) J. C. David. Mycopathologia 129:41, 1995.

Ultrastructure of conidia and conidium germination in the plant pathogenic fungus Alternaria cassiae

Transmission electron microscopy of plunge-frozen and freeze-substituted samples was used to examine germinating conidia of Alternaria cassiae, a plant pathogenic fungus used as a biological control agent for sicklepod (Cassia obtusifolia). Hydrated conidia on small pieces of dialysis membrane were incubated for 1, 2, or 3 h on the surface of corn meal agar prior to fixation. Conidia were large, darkly pigmented, and surrounded by a thick, two-layered wall. Each conidium was divided by transverse and longitudinal septa into multiple cells, a few of which sometimes appeared necrotic. Each septum tapered to a small central pore region with which Woronin bodies were associated. Each healthy cell of a conidium contained a typical complement of cellular organelles including multiple nuclei. With the exception of lipid bodies, all the various organelles were well preserved by plunge freezing and freeze substitution. Evidence of germ tube development was visible by 2 h post-incubation and well-developed germ tubes were present by 3 h. Two modes of germ tube development were observed. In the less common mode germ tubes developed inside conidia and grew internally through one or more adjacent cells before emerging from the conidium surface. Cells penetrated by internal germ tubes appeared necrotic. In the more common mode of germination, germ tubes developed directly from the conidium surface. Multiple germ tubes usually arose from each conidium and grew out in all directions. Germ tubes that contacted the underlying dialysis membrane continued to grow along its surface. Extracellular material was produced in association with developing germ tubes and coated the sides of germinated conidia and covered germ tubes growing along membranes. Key words: transmission electron microscopy, cryofixation, freeze substitution, germ tube development.

Pollinium development and number in the Orchidaceae

Development of anthers in three subfamilies of Orchidaceae was studied anatomically to examine homology hypotheses for pollinium number characters and to produce a model of pollinium development for the family. Serial sections of plastic‐embedded embryonic inflorescences revealed that anther primordia were either flattened or ovoid; subsequent expansion of thecae and their inward (adaxial) reorientation (“rotation”), achieved by differential cell division and elongation in the connective, result in a mature anther with strongly introrse morphology and pollinia oriented side by side (juxtaposed). Strongly introrse anthers occur in at least some members of all subfamilies and are probably the basal state for the family. All anthers examined (from Orchidoideae, Spiranthoideae, and Epidendroideae) showed a single meristematic region, which would later give rise to pollen, per theca at earliest stages; septation of each of these regions resulted in four or eight pollinia per anther, while lack of septation in some members of the Epidendroideae gave two pollinia. In contrast, the two bipartite pollinia found in many Spiranthoideae and Orchidoideae were produced by adherence of the contents of two locules at a late ontogenetic stage, and should be recognized as a distinct character state. Eight pollinia result from partitioning by two longitudinal septa or a longitudinal and a transverse septum; these two morphologies may also represent separate character states.

Cartilage-bone replacement in endochondral ossification of mandibular condylar heads in young beagle dogs.

The cellular mechanisms of cartilage-bone replacement in endochondral bone formation, in mandibular condylar heads, are poorly understood. In particular, there is no definitive evidence indicating whether cartilage is resorbed by so-called chondroclasts. Using 3-week-old male beagle dogs, we examined the cartilage-bone replacement processes in mandibular condylar heads by means of light and electron microscopy. Calcification of the cartilage matrix occurred in the central area of the longitudinal septa but not in thin transverse septa. Chondrocytic lacunae were opened by the removal of transverse septa by perivascular rough-surfaced endoplasmic reticulum (RER)-rich mononuclear cells. These cells also phagocytosed calcified cartilage fragments in the surface layer of longitudinal septa. Shortly thereafter, a thin bone layer was deposited on the remaining longitudinal septa by invading osteoblasts. Preosteoclastic multinucleated cells in lacunar canals developed neither ruffled borders nor clear zones in the cartilage matrix, but once the bone layer had been deposited on the remaining cartilage, these structures formed. Our results suggest that the cartilage-bone replacement in mandibular condylar heads involves four sequential processes: 1) degradation of the transverse septal cartilage by RER-rich mononuclear cells, 2) phagocytosis of calcified cartilage fragments in the longitudinal septa by these cells, 3) bone deposition of the remaining longitudinal septa, and 4) degradation of both bone and calcified cartilage by differentiated osteoclasts.

Preussomerin D from the Endophyte Hormonema Dematioides

Preussomerin A, an aromatic bis-ketal, was first isolated from the coprophilous fungus Preussia isomera Cain during a study of interspecies competition among dung inhabiting fungi (Weber et al., 1990). Upon further investigation, a group of compounds closely related to preussomerin A was isolated from the same organism and identified as preussomerin B, C, D, E, and F, some of which exhibited significant antifungal and antibacterial properties (Weber and Gloer, 1991). We report the isolation and antibiotic activity of preussomerin D (FIG. 1) from the endophytic fungus Hormonema dematioides Lagerberg & Melin recovered from living plant tissue of a coniferous tree. During a comparative study of fungal endophytes from apparently healthy living leaves and twigs of Chamaecyparis thyoides (L.) B.S.P. (white Atlantic cedar) collected from the Pine Barrens in the intercoastal region of New Jersey, H. dematioides was isolated infrequently from four of five study sites (Bills and Polishook, 1992). One particular isolate JP 184 was recovered from disinfected living foliage collected near Dover Forge, Ocean Co., New Jersey during the spring of 1990. When submitted for natural products screening, this fungus produced in vitro a cytotoxic compound L-733,757 that later proved by silica gel chomatography, mass spectrometry, high pressure liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) to be chemically identical to preussomerin D. Hormonema dematioides, a slow-growing black yeast usually associated with conifer wood, is characterized by basipetal conidiogenesis and dark, thick-walled hyphae with cells wider than long, often with longitudinal septa (FIG. 2) (Hermanides-Nijhof, 1977). It is morphologically similar to and often isolated from coniferous tissue along with Aureobasidium pullulans (de Bary)

Ascomal Development in Leptosphaerulina Crassiasca

Cultures of Leptosphaerulina crassiasca from single ascospores formed ascostromata, indicating that the fungus is homothallic. Mycelial hyphae were septate, with uninucleate cells, and they gave rise to fertile hyphae which were larger and had binucleate or multinucleate cells. Certain cells of the fertile hyphae divided repeatedly in all planes to form ascostromal initials. Small binucleate ascogonial cells with dense cytoplasm soon filled the central part of the young ascostroma; later they give rise to ascogenous cells that developed directly into asci. No sterile centrum tissues were formed. The asci contained eight ascospores which were initially uninucleate. Mature ascospores were multinucleate and had 3–5 transverse septa and 0–2 longitudinal septa. The ascus wall was two-layered, with the inner layer (endotunica) extending through the outer layer (ectotunica) during ascospore discharge. The ascoma is a uniloculate pseudothecium with a papillate ostiolar neck and bitunicate asci. Ascomal ontogeny is typical of the Dothidea type of development.

Taxonomic Studies on Australian Isolates of Stemphylium spp. And Associated Teleomorphs

Taxonomic studies on monosporic pure cultures of Australian isolates of Stemphylium revealed the presence of three species, namely S. botryosum, S. globuliferum and S. vesicarium. A group intermedi- ate between S. botryosum and S. vesicarium but more closely resembling S. vesicarium was recognised. The circumscription of S. vesicarium was broadened to accommodate this taxon which was found on Medicago sativa, M. rugosa and Simmondsia chinensis. Studies on herbarium specimens deposited as S. botryosum on M. sativa from a number of overseas locations indicated that in all cases the pathogen fitted our concept of S. vesicarium. Teleomorphs were induced in pure culture for each of the above-mentioned anamorphs, and in all instances the teleomorph was identified as Pleospora herbarum. The ascospore morphology was similar for all isolates, and the shape of the ends of the spore and the number of longitudinal septa were variable characters even within an isolate. However, the teleomorphs could be separated into two distinct groups on the basis of ascal length.

Pseudoachondroplasia

Cartilage from patients with pseudoachondroplasia is characterized by unique inclusions in the cisternae of the endoplasmic reticulum and proteoglycan abnormalities have been suggested in this form of dwarfism. To elucidate the nature of the proteoglycan defect, we determined the amount of the individual glycosaminoglycans present in iliac-crest cartilage of three patients and extracted the proteoglycan monomers from one of the samples. Sections of iliac-crest cartilage and proximal fibular growth plates were examined by electron microscopy and also stained with hematoxylin and eosin, safranin O-fast green, and alcian blue in the presence of increasing concentrations of magnesium chloride (zero to one molar). The chondrocytes of the iliac crest and fibular physes were arranged in clusters more than in columns and contained characteristic endoplasmic reticulum inclusions, which were particularly large in the hypertrophic cells. The cartilage stained very poorly with hematoxylin and eosin and with safranin O-fast green. The alcian-blue stain was abolished from perilacunar areas and from longitudinal septa by magnesium chloride concentrations that were lower than those required by normal tissue. The proteoglycans of iliac-crest cartilage were found to be significantly enriched in keratan sulphate and had a below-normal ratio of chondroitin-4-sulphate to chondroitin-6-sulphate, although the amount of the two isomeric chondroitin sulphates combined was within normal limits. The urinary excretion of glycosaminoglycan by the three patients was normal. Pseudoachondroplasia appears to be a generalized cartilage disorder involving abnormalities of proteoglycans, probably related to the core protein or to enzymes that are responsible for the formation of the glycosaminoglycan chains.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of an extracellular protein (chondrocalcin) with the calcification of cartilage in endochondral bone formation.

We examined bovine fetal epiphyseal and growth plate cartilages by immunofluorescence microscopy and immunoelectron microscopy using monospecific antibodies to a newly discovered cartilage-matrix calcium-binding protein that we now call chondrocalcin. Chondrocalcin was evenly distributed at relatively low concentration in resting fetal epiphyseal cartilage. In growth plate cartilage, it was absent from the extracellular matrix in the zone of proliferating chondrocytes but was present in intracellular vacuoles in proliferating, maturing and upper hypertrophic chondrocytes. The protein then disappeared from the lower hypertrophic chondrocytes and appeared in the adjoining extracellular matrix, where it was selectively concentrated in the longitudinal septa in precisely the same location where amorphous mineral was deposited in large amounts as demonstrated by von Kossa staining and electron microscopy. Mineral then spread out from these "nucleation sites" to occupy much of the surrounding matrix. Matrix vesicles were identified in this calcifying matrix but they bore no observable morphological relationship to these major sites of calcification where chondrocalcin was concentrated. Since chondrocalcin is a calcium-binding protein and has a strong affinity for hydroxyapatite, these observations suggest that chondrocalcin may play a fundamental role in the creation of nucleation sites for the calcification of cartilage matrix in endochondral bone formation.

Ultrastructural cytochemistry and immunocytochemistry of proteoglycans associated with epiphyseal cartilage calcification.

Proteoglycans (PGs) are closely associated with cartilage calcification. We have examined the hypertrophic zone of rat epiphyseal cartilage, in which calcification is occurring, using the high-iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) method for sulfated glycosaminoglycans, an immunoferritin method specific for chondroitin sulfate A, and the tannic acid-ferric chloride (TA-Fe) method to stain cartilage matrix granules (MGs) presumed to be PG monomers. HID-TCH-SP produced stain deposits with a diameter of 11.2 +/- 3.2 nm (mean +/- SD; n = 200) in the MGs. However, HID-TCH-SP staining was not discernible in membrane-limited matrix vesicles (MVs). In areas of advanced calcification, partially disrupted MVs and globular bodies (GBs), derived in part from disrupted and/or degenerated MVs, contained a few too many small HID-TCH-SP stain deposits. Further down the epiphyseal cartilage, intact MVs markedly decreased and the GBs, containing many small HID-TCH-SP stain deposits, significantly increased in number. These GBs were found exclusively in the longitudinal septa rather than in the transverse septa. After enzyme digestion with testicular hyaluronidase, small (7.2 +/- 1.2 nm in diameter) stain deposits remained in the MGs and GBs, presumably localized to keratan sulfate. Immunoferritin localizing chondroitin sulfate strongly stained MGs, whereas MVs and GBs lacked staining. TA-Fe staining of glycoconjugates in the GBs demonstrated a striking decrease in the diameter of MGs associated with calcification in the GBs as compared with those in the noncalcifying area around the GBs. These results indicate that the GBs containing needle-like apatite crystals in morphologic preparations represent sites of chondroitin sulfate degradation. Testicular hyaluronidase-resistant sulfated glycosaminoglycans presumed to be keratan sulfate and partially degraded PGs selectively remain within the GBs as a probable requisite for expansion of the initial calcification in MVs.