scholarly journals Aposporic development of gametophyte in Sematophyllum subpinnatum (Brid.) E. Britton (Sematophyllaceae) from capsule wall

2022 ◽  
Vol 9 (1) ◽  
pp. 48-51
Author(s):  
Meenu Mathew ◽  
Abraham Mathew ◽  
N Sindu
Keyword(s):  
Germ Tube ◽  
Axenic Culture ◽  
Normal Growth ◽  
Capsule Wall ◽  
First Report

In the present study, an axenic culture of Sematophyllum subpinnatum (Brid.) E. Britton was attempted from spores. However, spores failed to germinate, but protonemata were seen arising from the diploid capsule wall cells by apospory. Few cells of the capsule wall turned green, and the protoplast divided, resulting in the extension of the protoplast as a germ tube, which developed into protonemata. Protonemata were less spreading, and adult gametophytes developed from these protonemata. The aposporic plants so developed were transferred to soil, and they showed normal growth but with decreased branching. No sex organs and sporophytes were seen. This is the first report of aposporic development of S. subpinnatum from the capsule wall.

The in vitro induction of adventitious shoot and root apices on Narcissus (daffodil and narcissus) cultivar tissue

1976 ◽  
Vol 54 (9) ◽  
pp. 814-819 ◽  
Author(s):  
Janet E. A. Seabrook ◽  
Bruce G. Cumming ◽  
Leo A. Dionne
Keyword(s):  
Growth Regulators ◽  
Sucrose Solution ◽  
Axenic Culture ◽  
Normal Growth ◽  
Naphthaleneacetic Acid ◽  
Leaf Base ◽  
Rapid Propagation ◽  
Root Apices ◽  
Free Material

A new technique is reported here for the rapid propagation of Narcissus cultivars involving the induction of shoot and root apices from small pieces of leaf base tissue, inverted scape sections, and from ovaries, in axenic culture. Shoot and root apices were obtained on the above explants of all nine Narcissus cultivars tested. The optimal medium contained modified Murashige and Skoog (1962) inorganic salts, the organic constituents recommended by Ziv et al. (1970), and higher-than-normal growth regulator levels. Proliferating shoot apices were induced on a medium containing 4.4 × 10−5 M (10 mg/litre) 6-benzylaminopurine (BAP) and 5.3 × 10−6 M (1 mg/litre) naphthaleneacetic acid (NAA). Plantlets grew optimally if transferred to a medium containing 9.0 × 10−6 M (2 mg/litre) BAP and 2.0 × 10−7 M (2 mg/litre) NAA. The induction of roots on plantlets grown in vitro required a half-strength salt and sucrose solution without growth regulators.In 5 months, 2620 plantlets were produced from two leaf base explants. This technique is considerably more efficient than any known conventional methods of propagating Narcissus.Root apices were optimally produced on a medium containing 2.0 × 10−6 (0.5 mg/litre) to 2.0 × 10−5 M (4 mg/litre) BAP and 1.0 × 10−4 (20 mg/litre) to 2.0 × 10−5 (4 mg/litre) NAA. Callus was induced on leaf base explants, inverted scape sections, and on ovaries; the ovary expiants required the highest levels of auxin for the induction of callus and were most responsive. Thus, the levels of growth regulators required to induce a response in vitro are higher than so far reported for plants that have been propagated by tissue culture.Although the levels of various growth regulators used were found to be important in obtaining apices, the relative ratio of cytokinin to auxin was also found to be critical. Although considerable differences in clonal responsiveness were noted, cultures were obtained from all nine Narcissus cultivars tested.The induction of adventitious meristems of leaf base explants is a particularly promising method for the propagation of virus-free material and for the rapid propagation of valuable horticultural material.

Marine Phytoplankton Growth in High Concentrations of Pulpmill Effluent

1976 ◽  
Vol 33 (12) ◽  
pp. 2758-2765 ◽  
Author(s):  
John G. Stockner ◽  
Anne C. Costella
Keyword(s):  
Exponential Growth ◽  
Skeletonema Costatum ◽  
Axenic Culture ◽  
Normal Growth ◽  
Marine Phytoplankton ◽  
Culture Studies ◽  
Coastal Marine ◽  
High Concentrations ◽  
Kraft Effluent

Axenic culture studies with the marine phytoplankton Skeletonema costatum, Dunaliella tertiolecta, and Amphidinium carteri demonstrated the ability of these species to adapt to and exhibit normal growth in relatively high concentrations of pulpmill effluent. Skeletonema costatum and A. carteri required a preadaptation period prior to commencement of exponential growth in high concentrations of kraft effluent (20–30%), while D. tertiolecta exhibited exponential growth in 90% kraft effluent with no requirement for preadaptation. Of six pulpmill effluent types tested, kraft was considered most inhibitory to growth, while combined kraft and newsprint effluent passed through an XAD-8 resin column was least inhibitory. The effects of the six effluent types on lag, exponential, and stationary growth phases are discussed in relation to in situ concentrations and relative ecological significance in the coastal marine environment.

Isolation and axenic culture of poplar rust

1974 ◽  
Vol 52 (10) ◽  
pp. 2228-2229 ◽  
Author(s):  
W. David Lane ◽  
Michael Shaw
Keyword(s):  
Populus Trichocarpa ◽  
Axenic Culture ◽  
Fresh Medium ◽  
Black Cottonwood ◽  
First Report ◽  
Development In Vitro

Surface-sterilized leaf pieces of black cottonwood (Populus trichocarpa) leaves centered on uredial infections of Melampsora occidentalis Pers. were placed, pustule side up, on a defined, agar-based medium. After 4 months the fungus became established on the medium. Axenic colonies, some of which produced urediospores, were established by transfer to fresh medium and were capable of reinfecting excised leaf pieces of the host. The technique bypasses germling development in vitro. This is the first report of the axenic culture of Melampsora occidentalis.

scholarly journals First Report on Resistance to Pyraclostrobin, Thiophanate-methyl, Fenhexamid and Boscalid in Botrytis cinerea from Eucalyptus Seedlings in Florida Greenhouses

Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 851-851 ◽  
Author(s):  
A. Amiri ◽  
A. I. Zuniga ◽  
J. Mertely ◽  
N. A. Peres
Keyword(s):  
Botrytis Cinerea ◽  
Germ Tube ◽  
Crop Protection ◽  
Malt Extract ◽  
Thiophanate Methyl ◽  
First Report ◽  
Research Triangle ◽  
Extract Agar ◽  
Bayer Cropscience ◽  
Syngenta Crop Protection

Botryotinia fuckeliana de Bary (anamorph Botrytis cinerea Pers.) is an ubiquitous plant pathogen causing gray mold disease on more than 200 crops grown in the field or in greenhouses. Eucalyptus seedlings originating from three different greenhouses showing stem lesions were submitted to the Gulf Coast Research and Education Center Disease Clinic in June 2012. Ten single spore isolates of B. cinerea were obtained and tested for sensitivity using spore germination and germ tube elongation assays described previously (4). Fungicides tested were pyraclostrobin at 100 μg/ml (Cabrio, BASF, Research Triangle Park, NC), thiophanate-methyl at 100 μg/ml (Topsin-M, UPI, King of Prussia, PA), fenhexamid at 1 and 50 μg/ml (Elevate, Arysta Life Sciences, Cary, NC), fludioxonil at 0.1 and 10 μg/ml (Medallion, Syngenta Crop Protection, Research Triangle Park, NC), and iprodione at 5 and 50 μg/ml (Rovral, Bayer CropScience, Greensboro, NC) on 1% malt extract agar (MEA, 10 g malt extract and 15 g agar), and to cyprodinil at 1 and 25 μg/ml (Vanguard, Syngenta Crop Protection) on 0.5% sucrose agar (4). Sensitivity to the succinate dehydrogenase inhibitors (SDHIs) boscalid at 5 μg/ml (Endura, BASF), penthiopyrad at 1 and 3 μg/ml (Fontelis, DuPont Crop Protection, Willington, DE), and fluopyram at 3 μg/ml (Luna Privilege, Bayer CropScience) was evaluated on yeast bacto acetate agar (YBA) (3). The discriminatory dose for boscalid was adapted from (2) whereas those used for penthiopyrad and fluopyram were developed in this study. Isolates were grown on malt yeast extract agar for 7 to 10 days and spore suspensions were prepared in sterile distilled water and diluted to 106 conidia/ml. Respective media in 9-cm petri dishes were seeded with 7-μl droplets from each isolate allowing testing for all isolates on one plate. Two plates were used for each fungicide and sensitivity tests were repeated twice. Germination and germ tube growth were assessed microscopically after 16 to 24 h incubation at 22°C. The frequency of isolates resistant to two, three, and four fungicides was 90, 60, and 10%, respectively. Nine isolates (90%) were resistant to thiophanate-methyl and pyraclostrobin, simultaneously, whereas six (60%) and two isolates (20%) were resistant to boscalid and fenhexamid, respectively. All boscalid-resistant isolates were also resistant to pyraclostrobin and thiophanate-methyl, but one fenhexamid-resistant isolate was sensitive to the other three fungicides. Eight isolates that germinated at 5 μg/ml iprodione but not at 50 μg/ml were considered sensitive. All isolates were sensitive to the SDHIs penthiopyrad and fluopyram as well as to cyprodinil and fludioxonil. To our knowledge, this is the first report of resistance to pyraclostrobin, thiophanate-methyl, fenhexamid, and boscalid in B. cinerea from eucalyptus seedlings in Florida. The absence of resistance to fludioxonil and iprodione is likely because these fungicides are not registered in nurseries as well as fluopyram and penthiopyrad which were developed only recently. Management practices should be developed to limit the selection and spread of additional resistant populations in eucalyptus nurseries as has occurred in Florida strawberries where multi-fungicide resistance is widespread (1). References: (1) A. Amiri et al. Plant Dis. 97:393, 2013. (2) M. Leroch et al. Appl. Environ. Microbiol. 79:159, 2013. (3) G. Stammler and J. Speakman. J. Phytopathol. 154:508, 2006. (4) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011.

scholarly journals First Report of Powdery Mildew Caused by Erysiphe heraclei on Chervil in California

Plant Disease ◽  
2004 ◽  
Vol 88 (10) ◽  
pp. 1163-1163
Author(s):  
S. T. Koike ◽  
G. S. Saenz
Keyword(s):  
Powdery Mildew ◽  
Host Range ◽  
Germ Tube ◽  
Apium Graveolens ◽  
Petroselinum Crispum ◽  
First Report ◽  
Tube Forming ◽  
Disease Impact ◽  
Symptoms And Signs ◽  
Culinary Herb

Chervil (Anthriscus cerefolium) is a culinary herb in the Apiaceae family that is grown commercially in California. In 2003 and 2004, shade house plantings of chervil in central coastal California exhibited symptoms and signs of a powdery mildew disease. White, epiphytic mycelia and conidia were present on petioles and leaves. Severely affected leaflets became slightly twisted and bent. Mycelium was amphigenous and effused or in patches. Hyphae measured 5.0 to 7.5 μm in diameter and had lobed appressoria. Conidiophores were straight and had cylindric foot cells measuring 25.0 to 37.5 × 7.5 to 10.0 μm, followed by a longer cell and one to two shorter cells. Conidia formed singly, were cylindric, and measured (37.5-) 40.0 to 50.0 (-52.5) × 15.0 to 17.5 μm. Conidia lacked fibrosin bodies and germinated at the ends with either a very short or a long germ tube forming a lobed appressorium (Polygoni type). No cleistothecia were observed. On the basis of these characteristics, the fungus was identified as Erysiphe heraclei (1). To confirm pathogenicity, severely colonized chervil leaves from a commercial nursery were gently pressed onto leaves of potted chervil plants. Plants were then maintained in a greenhouse (22 to 24°C). After 10 to 12 days, signs of powdery mildew developed on the foliage of inoculated plants, and the pathogen morphology matched that of the originally observed pathogen. Noninoculated control plants did not develop powdery mildew. To investigate the host range of this chervil isolate, parsley (Petroselinum crispum) and celery (Apium graveolens) plants were inoculated in the same way as described. However, after more than 3 weeks, no powdery mildew developed on these two Apiaceae plants. Control chervil plants again developed the disease. To our knowledge, this is the first report of powdery mildew of chervil caused by E. heraclei in California. Disease impact was severe, and in some cases, chervil crops were not harvested. The inability of the chervil isolate to infect two other Apiaceae plants that are listed as hosts of E. heraclei indicates that this pathogen may consist of strains having different host ranges. Reference: (1) U. Braun. Nova Hedwigia 89:1, 1987.

Association of Trechispora alnicola with yellow ring disease of Poa pratensis

1987 ◽  
Vol 65 (1) ◽  
pp. 150-153 ◽  
Author(s):  
H. T. Wilkinson
Keyword(s):  
Germ Tube ◽  
Culture Medium ◽  
Poa Pratensis ◽  
Crystalline Material ◽  
First Report

Trechispora alnicola (Bourd. & Galz.) Liberia was associated with Poa pratensis L. roots and in the thatch layer of blue-grass sod. These plants had yellowed leaves. On thatch and culture medium, the fungus isolated from diseased plants produced hyaline mycelium typical of T. alnicola, and crystalline material. Conidia produced on thatch or on culture medium germinated by the production of a single germ tube. Basidia from basidiomata produced in nature were arranged in an effused manner; basidiospores were echinulate. This is the first report of T. alnicola associated with a member of the Graminae.

Ultrastructure of basidiospore germination and development of intrasporal hyphae in the snow mold, Coprinus psychromorbidus

1991 ◽  
Vol 37 (9) ◽  
pp. 697-702 ◽  
Author(s):  
J. A. Traquair ◽  
E. G. Kokko ◽  
E. R. Moskaluk
Keyword(s):  
Electron Microscopy ◽  
Germ Tube ◽  
Dense Body ◽  
Axenic Culture ◽  
Potato Dextrose Agar ◽  
Normal Complement ◽  
Transmission Electron ◽  
Apical Pore ◽  
Dense Cell ◽  
First Time

Basidiospores of Coprinus psychromorbidus, produced for the first time in axenic culture, were germinated on potato dextrose agar in slide culture. After incubation for 24 h, all stages of germination, the development of monokaryotic and dikaryotic hyphae, and the invasion of ungerminated basidiospores were observed using standard transmission electron microscopy. Each basidiospore has a complex, layered wall and dense cell contents containing one nucleus and the normal complement of organelles, plus lipids and dense-body vacuoles. The germ tube emerges through an apical pore in the basidiospore wall. Some abnormal ungerminated spores are invaded by adjacent germling hyphae, which enter through the pore and the hilum. Key words: basidiospore, transmission electron microscopie, invasion.

A fossil Aspergillus from Eocene Dominican amber

1988 ◽  
Vol 62 (01) ◽  
pp. 141-143 ◽  
Author(s):  
Gerard M. Thomas ◽  
George O. Poinar
Keyword(s):  
Dominican Republic ◽  
Fossil Species ◽  
First Report ◽  
Dominican Amber ◽  
Eocene Amber

A sporulating Aspergillus is described from a piece of Eocene amber originating from the Dominican Republic. The Aspergillus most closely resembles a form of the white spored phase of Aspergillus janus Raper and Thom. This is the first report of a fossil species of Aspergillus.

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