Length of cuttings in juvenile development of a hybrid poplar clone

New Forests ◽  
1991 ◽  
Vol 5 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Pekka Rossi
Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2220 ◽  
Author(s):  
Isabel Nogues ◽  
Paola Grenni ◽  
Martina Di Lenola ◽  
Laura Passatore ◽  
Ettore Guerriero ◽  
...  

Polychlorinated byphenyls (PCBs) are a class of Persistent Organic Pollutants extremely hard to remove from soil. The use of plants to promote the degradation of PCBs, thanks to synergic interactions between roots and the natural soil microorganisms in the rhizosphere, has been proved to constitute an effective and environmentally friendly remediation technique. Preliminary microcosm experiments were conducted in a greenhouse for 12 months to evaluate the capacity of the Monviso hybrid poplar clone, a model plant for phytoremediation, to grow in a low quality and PCB-contaminated soil in order to assess if this clone could be subsequently used in a field experiment. For this purpose, three different soil conditions (Microbiologically Active, Pre-sterilized and Hypoxic soils) were set up in order to assess the capacity of this clone to grow in the polluted soil in these different conditions and support the soil microbial community activity. The growth and physiology (chlorophyll content, chlorophyll fluorescence, ascorbate, phenolic compounds and flavonoid contents) of the poplar were determined. Moreover, chemical analyses were performed to assess the concentrations of PCB indicators in soil and plant roots. Finally, the microbial community was evaluated in terms of total abundance and activity under the different experimental conditions. Results showed that the poplar clone was able to grow efficiently in the contaminated soil and to promote microbial transformations of PCBs. Plants grown in the hypoxic condition promoted the formation of a higher number of higher-chlorinated PCBs and accumulated lower PCBs in their roots. However, plants in this condition showed a higher stress level than the other microcosms, producing higher amounts of phenolic, flavonoid and ascorbate contents, as a defence mechanism.


Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 770-770 ◽  
Author(s):  
N. Feau ◽  
L. Bernier

During the summer of 2001, leaf spots resembling those caused by Septoria musiva Peck. were observed on shining willow (Salix lucida Mühl. subsp. lucida) at Leclerville, Québec, Canada (46°34′19″N,71°59′35″W). Affected leaves had brown, necrotic leaf spots (>5mm in diameter) surrounded by a darker brown halo. Conidia were cylindrical, straight to curved with 1 to 4 septa, 28 to 54 × 3.5 to 4 μm, and were produced in pycnidia located on the abaxial surface in the center of the leaf spots. The causal agent of this disease was successfully isolated by germinating the conidia on corn meal agar that was supplemented with streptomycin (50mg/ml) and chloramphenicol (300mg/ml) and followed with the transfer of the germinated conidia to potato dextrose agar. Leaf symptoms and morphology matched those of S. musiva, the cause of leaf spot and stem canker of hybrid poplars in North America (2,4). The internal transcribed spacers and the 5.8S portion of the rDNA were amplified using PCR with the ITS1 (5′-TCC GTA GGT GAA CCT GCG G-3′) and ITS2 (5′-GCT GCG TTC TTC ATC GAT GC-3′) primer pair on total genomic DNA extracted from a pure culture of the pathogen. The rDNA sequence obtained (GenBank Accession No. AY555277) had 100% identity at 506 base positions with the ITS1, 5.8S, and ITS2 of three S. musiva isolates from Québec and one from Wisconsin (GenBank Accession Nos. AY549464 to AY549467). To test for pathogenicity, excised leaf disks from plants propagated by softwood cuttings of the source plant and from one hybrid poplar clone (Populus maximowiczii × P. xjackii) were inoculated with 3 μl of a suspension of ground mycelium or sterile water (control). Disks were placed in a 24-well tissue culture plate with 1 ml of distilled water per well and incubated in a growth room maintained at 22°C with a 16-h photoperiod. After 1 month, symptoms were similar to those previously observed. Isolates collected from shining willow or hybrid poplar were able to induce S. musiva leaf spot symptoms on leaf disks excised from shining willow or the hybrid poplar clone. From symptomatic leaf disks, S. musiva was consistently reisolated. To our knowledge, this is the first report of S. musiva on a member of the genus Salix. S. didyma, S. salicicola, and S. salicina have been reported from leaves of species of Salix (1,3). Only a vague morphological description of S. didyma was found (3). Moreover, conidia of S. salicicola (20 to 50 × 2.5 to 3.5 μm) and S. salicina (40 to 60 μm long, unspecified width) overlap dimensions of S. musiva conidia (1). There is a need to reexamine the relationships between these species of Septoria. Evidently, the complete host range of S. musiva is not yet known. References: (1) L. Lanier et al. Mycologie et Pathologie Forestières. Masson. Paris, 1978. (2) M. E. Ostry. Eur. J. For. Pathol. 17:158, 1987. (3) P. A. Saccardo. Sylloge fungurum omnium hucusque cognitorum. Patavii: Sumptibus Auctoris, 1882. (4) L. J. Spielman et al. Plant Dis. 70:968, 1986.


1981 ◽  
Vol 11 (4) ◽  
pp. 830-833
Author(s):  
A. R. Biggs ◽  
D. D. Davis

Growth of hybrid poplar clone NE-388 (Populusmaximowizii Henry × trichocarpa Torr. & Gray) was significantly reduced by repeated continuous 72-h exposures to 0.12 or 0.25 ppm SO2 for 6 or 14 weeks, respectively. Both dosages of SO2 induced significant defoliation of the oldest leaves. The sulfur content of abscised foliage ranged from 0.90 to 1.70% S dry weight basis compared with control values of 0.24 to 0.32% S. These sulfur values may provide information on the role of hybrid poplar in removing pollutants from the atmosphere.


2020 ◽  
Vol 324 (2) ◽  
pp. 242-251
Author(s):  
L.P. Flyachinskaya ◽  
P.A. Lezin

The paper considers the development of Ciliatocardium ciliatum from the stage of straight hinge to juvenile. In the White Sea the spawning of C. ciliatum begins at the end of June, larvae at different stages of development occur in plankton until the end of September. The earliest of the larvae found had shell lengths of 123–130 µm. The paper first examined the anatomy and structure of the larval shell of C. ciliatum. During the development, the main stages of organogenesis were described and special attention was paid to the formation of the digestive and muscular systems. The digestive system begins to function when the larva reaches a size of 170–180 µm. The digestive gland has a two-blade shape and is shifted to the right side. The foot is formed at a size of 230 µm, the gill rudiments appear when the larva reaches 270 µm. The development of the larval shell and larval hinge of the mollusc is considered in detail. The development of the larval shell of C. ciliatum is similar to the development of other family members. Throughout all the larval stages, the shell has a rounded shape with a low umbos, and the prodissoconch II has a clearly visible concentric structure. The C. ciliatum larval hinge is characterized by weak differentiation and the absence of pronounced cardinal teeth typical for other Cardiidae. However, the lateral structures of the castle – ridges and flanges – are well developed. The ligament begins to form at a size of 240–250 µm and occupies a lateral position. The settlement of the cockle takes place in September in the subtidal zone. After the metamorphosis, a large radial sculpture is formed on the dissoconch and a number of small spikes are formed at the rib of the posterior shoulder.


2013 ◽  
Vol 18 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Zhaohong SHI ◽  
Shiming PENG ◽  
Jiangang WANG ◽  
Peng SUN ◽  
Fei YIN

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