scholarly journals Effect of Watering Regime on Disease Development in Pinus sylvestris Seedlings Inoculated with Bursaphelenchus vallesianus and B. mucronatus

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1055-1061 ◽  
Author(s):  
J. Polomski ◽  
D. Rigling
Keyword(s):  
Drought Stress ◽  
Pinus Sylvestris ◽  
Nematode Species ◽  
Disease Development ◽  
Nematode Density ◽  
Highly Pathogenic ◽  
Initial Inoculum ◽  
Nematode Population Density ◽  
Pine Trees ◽  
Dead Plant

Several Bursaphelenchus spp. have been detected in declining pine trees in Europe during intensive monitoring for the pine wood nematode B. xylophilus. We investigated the pathogenicity of B. vallesianus and B. mucronatus, isolated from declining Scots pine (Pinus sylvestris) forests in Valais (Switzerland), in relation to drought stress. Four isolates of B. vallesianus and two isolates of B. mucronatus were inoculated into 3-year-old P. sylvestris trees, which were subjected to different watering treatments (50, 100, 150, and 250 ml of water per pot, biweekly). Disease symptoms, plant mortality, nematode population density, and nematode distribution in dead plants were assessed. Both Bursaphelenchus spp. proved highly pathogenic to the seedlings and watering treatment affected disease development in the inoculated pine trees. With decreasing water supply, we observed faster disease progress and higher pine mortality for both Bursaphelenchus spp. The overall mortality 70 days after inoculation was 60, 92, 95, and 100% for B. vallesianus and 40, 95, 100, and 100% for B. mucronatus in the 250-, 150-, 100-, and 50-ml watering treatments, respectively. Both nematode species multiplied in the inoculated plants; however, B. mucronatus had higher population densities than B. vallesianus in all watering treatments (on average, 33,159 versus 14,702 nematodes/dead plant compared with the initial inoculum density of 6,000 nematodes/plant). The highest nematode density was found in the lower part of the stem. About 7 to 16% of the nematodes were extracted from the roots. This study demonstrated that B. vallesianus has a pathogenicity potential comparable with that of B. mucronatus and provided experimental evidence that drought stress can result in increased symptoms caused by either Bursaphelenchus sp.

Suppressive effects of Bursaphelenchus mucronatus on pine wilt disease development and mortality of B. xylophilus-inoculated pine seedlings

Nematology ◽  
2014 ◽  
Vol 16 (2) ◽  
pp. 219-227 ◽  
Author(s):  
Si-Mi Liao ◽  
Satomi Kasuga ◽  
Katsumi Togashi
Keyword(s):  
Pine Wilt Disease ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Reproductive Interference ◽  
Dependent Manner ◽  
Nematode Density ◽  
Pine Wilt ◽  
Bursaphelenchus Mucronatus ◽  
Pine Trees

Bursaphelenchus xylophilus causes pine wilt disease in Pinus trees whereas B. mucronatus has no or little virulence to the trees. Interspecific crossing experiments conducted so far suggest reproductive interference between the two nematode species. Theory predicts that one of the two competing species populations quickly displaces the other through reproductive interference in a frequency-dependent manner. Thus, it is anticipated that B. mucronatus suppresses the virulence of B. xylophilus against pine trees when B. mucronatus heavily outnumber B. xylophilus. To determine the suppressive effects of B. mucronatus, the two nematode species were inoculated simultaneously on 30 3-year-old Pinus thunbergii seedlings at three combinations of different numbers, and B. xylophilus alone was inoculated on 30 other seedlings at the corresponding numbers in early August. Seedlings were observed at intervals of 4 or 6 weeks and two stem sections were sampled from each seedling to determine the density and species composition of nematode populations after death or in December. Inoculation of B. mucronatus significantly retarded the speed of foliage discolouration from 0.170 ± 0.024 week−1 to 0.061 ± 0.017 week−1 and significantly prolonged the survival time of seedlings. Bursaphelenchus mucronatus significantly reduced the nematode density from 1799.7 ± 305.0 to 521.0 ± 148.4 (g dried seedling stem)−1. Analysis of rDNA genotype showed 1846 B xylophilus, no B. mucronatus and one hybrid.

scholarly journals Scots pine (Pinus sylvestris) dynamics in the Welsh Marches during the mid to late-Holocene

The Holocene ◽  
2021 ◽  
pp. 095968362199465
Author(s):  
Dael Sassoon ◽  
William J Fletcher ◽  
Alastair Hotchkiss ◽  
Fern Owen ◽  
Liting Feng
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Late Holocene ◽  
British Isles ◽  
Loss On Ignition ◽  
Peat Core ◽  
New Information ◽  
Pine Trees ◽  
Pollen Records

Around 4000 cal yr BP, Scots pine ( Pinus sylvestris) suffered a widespread demise across the British Isles. This paper presents new information about P. sylvestris populations found in the Welsh Marches (western central Britain), for which the long-term history and origins are poorly known. Two new pollen records were produced from the Lin Can Moss ombrotrophic bog (LM18) and the Breidden Hill pond (BH18). The LM18 peat core is supported by loss-on-ignition, humification analysis and radiocarbon dating. Lead concentrations were used to provide an estimated timeframe for the recent BH18 record. In contrast to many other Holocene pollen records from the British Isles, analysis of LM18 reveals that Scots pine grains were deposited continuously between c. 6900–300 cal yr BP, at frequencies of 0.3–5.4%. It is possible that individual Scots pine trees persisted through the wider demise on thin soils of steep drought-prone crags of hills or the fringes of lowland bogs in the Welsh Marches. At BH18, the record indicates a transition from broadleaved to mixed woodland, including conifer species introduced around AD 1850 including Picea and Pinus. The insights from BH18 suggest that the current populations may largely be the result of planting. Comparison of the LM18 findings with other regional pollen records highlights consistent patterns, including a Mid-Holocene maximum (ca. 7000 cal yr BP), long-term persistence at low pollen percentages and a Late-Holocene minimum (ca. 3000 cal yr BP). These distinctive trends encourage further studies on refugial areas for Scots pine in this region and elsewhere.

scholarly journals CHRONIC IRRADIATION OF SCOTS PINE TREES (PINUS SYLVESTRIS) IN THE CHERNOBYL EXCLUSION ZONE: DOSIMETRY AND RADIOBIOLOGICAL EFFECTS

2011 ◽  
Vol 101 (4) ◽  
pp. 393-408 ◽  
Author(s):  
Vasyl I. Yoschenko ◽  
Valery A. Kashparov ◽  
Maxim D. Melnychuk ◽  
Svjatoslav E. Levchuk ◽  
Yulia O. Bondar ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Chronic Irradiation ◽  
Exclusion Zone ◽  
Pine Trees ◽  
Radiobiological Effects

A study of the olfactory responses of insect parasites to the food plant of their host

Parasitology ◽  
1938 ◽  
Vol 30 (4) ◽  
pp. 523-528 ◽  
Author(s):  
W. H. Thorpe ◽  
H. B. Caudle
Keyword(s):  
Pinus Sylvestris ◽  
Adult Life ◽  
Egg Laying ◽  
Food Plant ◽  
Next Generation ◽  
Considerable Time ◽  
Olfactory Responses ◽  
The Third ◽  
Pine Trees ◽  
Insect Parasites

1. Pimpla ruficollis is a parasite of the pine shoot moth Rhyacionia (Evetria) buoliana Schiff. (Eucosmidae) which emerges from its host a considerable time before the next generation of larvae are ready for oviposition. It seems that during this period the parasites leave the pine trees and feed on the flowers of certain Umbelliferae and probably other plants. Only after 3 or 4 weeks do they return to the pine trees where the shoots now contain larvae ready for egg laying.2. It has been shown by means of olfactometer experiments that during this first period of the adult life, the parasites are repelled by the odour of oil of Pinus sylvestris. At this time the ovaries are very small and are probably not ready for the production of eggs. After the third or fourth week of life the females become attracted by the oil of P. sylvestris and the ovaries are now relatively large.3. Since Geraniol is known to be a constituent of certain conifers, this substance was also tested. It was, however, found to be invariably repellent to the parasites.4. There is some evidence that conclusions reached as a result of experiments with P. ruficollis also apply to the ophionine ichneumonid Eulimneria rufifemur.

Boarding abilities of Bursaphelenchus mucronatus and B. xylophilus (Nematoda: Aphelenchoididae) on Monochamus alternatus (Coleoptera: Cerambycidae)

Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 843-849 ◽  
Author(s):  
Shota Jikumaru ◽  
Katsumi Togashi
Keyword(s):  
Pine Wilt Disease ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Insect Vector ◽  
Species Replacement ◽  
Monochamus Alternatus ◽  
Bursaphelenchus Mucronatus ◽  
Initial Load ◽  
Pine Trees ◽  
The Difference

Abstract Bursaphelenchus mucronatus is closely related to Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Both nematodes are transmitted between host pine trees as the fourth-stage dispersal juveniles (JIV) by insect vectors. After the invasion of Japan by B. xylophilus, B. mucronatus, native to Japan, appears to have been replaced in the pine forests during the spread of the disease. To help understand this species replacement, the number of JIV carried by an insect vector (the initial nematode load) was compared between the two nematode species by using the beetle, Monochamus alternatus, in the laboratory. The initial load of B. mucronatus was significantly smaller than that of B. xylophilus although the number of third-stage dispersal juveniles (JIII) concentrated at the pupal chambers did not differ. Statistical analysis showed that the proportion of JIII moulting to JIV was the most important among three components explaining the difference in the initial load of B. mucronatus while the number of JIII concentrated at the pupal chamber was the most important for B. xylophilus. The phoretic affinity between the nematode and its vector is discussed in relation to its role in the species replacement.

scholarly journals Effects of pruning on heartwood formation in Scots pine trees

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 11-16
Author(s):  
B. Bergström ◽  
R. Gref ◽  
A. Ericsson
Keyword(s):  
Growth Rate ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Heartwood Formation ◽  
Growth Rings ◽  
Significant Negative Effect ◽  
Growing Seasons ◽  
Pine Trees ◽  
Negative Effect ◽  
Proportional Increase

The object of this study was to investigate the effect of pruning on heartwood formation in mature Scots pine (Pinus sylvestris L.) trees. Fifty trees were treated by three different intensive pruning regimes: 42, 60 and 70 percentage of defoliation. After five growing seasons numbers of growth rings were counted and the width and the area of sapwood and heartwood were calculated. The results did not show any proportional increase or decrease in the heartwood area or in the number of growth rings in heartwood associated with the pruning. A statistically significant negative effect of pruning was found on the width of the five most recently formed sapwood growth rings. This decreased growth rate did not influence the ratio of sapwood and heartwood. However, it cannot be excluded that the proportion of heartwood may increase during a longer period. It is concluded that pruning is not a practicable silvicultural method for regulating heartwood formation in mature Scots pine trees.

scholarly journals First Report of the East-Asian Type of Bursaphelenchus mucronatus in Pinus sylvestris in Slovenia

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1015-1015
Author(s):  
G. Urek ◽  
S. Širca
Keyword(s):  
Pinus Sylvestris ◽  
East Asian ◽  
Abies Alba ◽  
Rflp Analysis ◽  
The European Union ◽  
Conifer Forest ◽  
Bursaphelenchus Mucronatus ◽  
Three Samples ◽  
Pine Trees ◽  
First Time

Bursaphelenchus mucronatus Mamiya & Enda, a nematode associated with aboveground tissues of pine trees, is very similar morphologically to the pine wood nematode (PWN), B. xylophilus, a devastating pest that has caused widespread losses to pine woods in some parts of Asia since the early 1900s. During 1999, B. xylophilus was identified for the first time in Europe in Portugal (3), leading to concern that pines and other conifers all over Europe might be endangered. To protect forests from PWN and other pests, the European Union and other countries now regulate the importation of all coniferous chips, sawn wood, and logs and also have organized surveys to determine the extend of PWN infestation. Slovenia has approximately 1,227,832 ha of forest that makes up more than 60% of the surface of the country. The percentage of conifers within forests is 47.9% and comprised mainly of Picea, Pinus, Abies, and Larix species (2). During the summers of 2002-2004, approximately 100 ha of conifer forests in Slovenia were surveyed for the presence of PWN. In total, 170 wood samples from dead and dying pine (Pinus sylvestris L., P. nigra Arnold), spruce (Picea abies L.), and fir (Abies alba Miller) were analyzed. B. xylophilus (Steiner & Buhrer) Nickle was not found in the area, but a closely related nematode, B. mucronatus, previously shown to be pathogenic on conifer seedlings (4), was isolated from samples of P. sylvestris. Of 34 P. sylvestris samples analyzed, B. mucronatus was found in three samples. Samples were taken from a conifer forest located in the central part of Slovenia near the international airport of Ljubljana. The species was identified morphologically and also characterized by polymerase chain reaction restriction (PCR)-fragment length polymorphism (RFLP) analysis on the basis of ITS-rDNA fragment patterns. According to RFLP patterns (1), the analyzed species was recognized as the East-Asian type of B. mucronatus. Beside these findings, the specimens of B. homanni (Braasch) and Bursaphelenchus sp. have also been found in Slovenia. The results of the survey show that PWN was not found in Slovenia, but three different species of the Bursaphelenchus genus were present. References: (1) H. Braasch et al. Nachrbl. Dtsch. Pflanzenschutzd. 51:312, 1999. (2) M. Jurc et al. Zb. Gozdarstva in Lesarstva 72:121, 2004. (3) M. M. Mota et al. Nematology 1:727, 1999. (4) J. R. Sutherland. Pine wilt nematode. Pages 19–20 in: Compendium of Conifer Diseases. E. M. Hansen and K. J. Lewis, eds. The American Phytopathological Society, St. Paul, MN. 1997.

scholarly journals An interesting chemical polymorphism in Pinus sylvestris L.

2014 ◽  
Vol 51 (3-4) ◽  
pp. 441-452 ◽  
Author(s):  
Jerzy Szweykowski ◽  
Lech Urbaniak
Keyword(s):  
Phenolic Compounds ◽  
Pinus Sylvestris ◽  
Chemical Polymorphism ◽  
Pine Trees

Intra- and interpopulational polymorphism in the production of phenolic compounds is described in Polish populations of <em>Pinus sylvestris</em> L. Two mutually exclusive forms of pine trees are present in changing proportions in all populations studied. This allows three groups of populations to be distinguished. The character of this differentiation is discussed.

scholarly journals Vertical Distribution of Pratylenchus Alleni and P. Scribneri in Soybean Roots

1969 ◽  
Vol 66 (1) ◽  
pp. 60-64
Author(s):  
N. Acosta
Keyword(s):  
Population Density ◽  
Vertical Distribution ◽  
Root Zone ◽  
Lateral Roots ◽  
Nematode Species ◽  
Nematode Population ◽  
Infested Soil ◽  
Nematode Population Density ◽  
Soybean Roots ◽  
Total P

In a study of the distribution of Pratylenchus alleni and P. scribneri within Clark 63 soybean roots from nematode-infested soil, populations of both nematode species were most abundant in the first 10-15 cm of the root zone, 30 days after planting. There was a distinct decrease in nematode population density in both species with depth of the taproot. Fifty percent of the total P. alleni population in lateral roots was located in the first 5 cm from the taproot, whereas only 26% of P. scribneri population occurred in this region.

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