scholarly journals Factors Affecting the Ratio of Female to Male of Pinewood Nematodes Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 763
Author(s):  
Pengfei Wei ◽  
Yongxia Li ◽  
Wei Zhang ◽  
Mengge Gao ◽  
Zhenkai Liu ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Maternal Age ◽  
Environmental Changes ◽  
Population Change ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Factors Affecting ◽  
Primary Sex Ratio ◽  
Pinewood Nematodes ◽  
In The Wild

The pinewood nematode Bursaphelenchus xylophilus (B. xylophilus) is responsible for a devastating disease of pine forests. Its pathogenicity is closely related to the numbers of individual B. xylophilus. The ratio of female to male (sex ratio) is key to understanding population change in this species. The sex ratio of B. xylophilus varies widely, but it is unclear how it is affected by environmental changes. The sex ratios of nematodes, isolated from different samples in the wild, varied between 0.93 and 2.20. Under laboratory conditions, maternal age and the population did not affect the sex ratio of progeny. A change from good to poor nutritional status was associated with a reduction of the sex ratio of progeny from 1.85 to 1.41, which was speculated to result from a change in the primary sex ratio. Thus, B. xylophilus effectively maintains the sex ratio with maternal age and population changes but adjusts the sex ratio of progeny on the basis of the changes in nutrition.

INCIDENCE OF THE PINEWOOD NEMATODE1 IN A SOUTHERN PINE BEETLE2 INFESTATION IN CENTRAL LOUISIANA

1986 ◽  
Vol 21 (2) ◽  
pp. 114-117 ◽  
Author(s):  
D. N. Kinn
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Bursaphelenchus Xylophilus ◽  
Dendroctonus Frontalis ◽  
Southern Pine Beetle ◽  
Pinewood Nematode ◽  
Southern Pine ◽  
Pine Beetle ◽  
Pinewood Nematodes ◽  
Pinus Taeda L

A large infestation of southern pine beetle, (Dendroctonus frontalis Zimm.), located in central Louisiana, was surveyed for the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle. Pinewood nematodes were present in 4.2 percent of 94 loblolly pine (Pinus taeda L.) trees attacked by D. frontalis and were absent from 101 unattacked trees that surrounded the infestation. Monthly sampling of this infestation revealed an increase in the incidence of nematodes as the season progressed. Samples taken from different heights on beetle infested-boles did not differ significantly in the presence of nematodes.

scholarly journals Effects of natural nest temperatures on sex reversal and sex ratios in an Australian alpine skink

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Duminda S. B. Dissanayake ◽  
Clare E. Holleley ◽  
Arthur Georges
Keyword(s):  
Sex Ratio ◽  
Climatic Variability ◽  
Population Decline ◽  
Sex Reversal ◽  
Individual Fitness ◽  
Primary Sex Ratio ◽  
In The Wild ◽  
Genotypic Sex Determination ◽  
Environmental Temperatures ◽  
Bassiana Duperreyi

AbstractAltered climate regimes have the capacity to affect the physiology, development, ecology and behaviour of organisms dramatically, with consequential changes in individual fitness and so the ability of populations to persist under climatic change. More directly, extreme temperatures can directly skew the population sex ratio in some species, with substantial demographic consequences that influence the rate of population decline and recovery rates. In contrast, this is particularly true for species whose sex is determined entirely by temperature (TSD). The recent discovery of sex reversal in species with genotypic sex determination (GSD) due to extreme environmental temperatures in the wild broadens the range of species vulnerable to changing environmental temperatures through an influence on primary sex ratio. Here we document the levels of sex reversal in nests of the Australian alpine three-lined skink (Bassiana duperreyi), a species with sex chromosomes and sex reversal at temperatures below 20 °C and variation in rates of sex reversal with elevation. The frequency of sex reversal in nests of B. duperreyi ranged from 28.6% at the highest, coolest locations to zero at the lowest, warmest locations. Sex reversal in this alpine skink makes it a sensitive indicator of climate change, both in terms of changes in average temperatures and in terms of climatic variability.

Factors affecting the number of Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) carried by several species of beetles

Nematology ◽  
2002 ◽  
Vol 4 (5) ◽  
pp. 653-658 ◽  
Author(s):  
Noritoshi Maehara ◽  
Kazuyoshi Futai
Keyword(s):  
Bursaphelenchus Xylophilus ◽  
The Other ◽  
Monochamus Alternatus ◽  
Factors Affecting ◽  
Pine Wilt ◽  
Blue Stain Fungi ◽  
Pinewood Nematodes ◽  
Blue Stain

AbstractNumerous pinewood nematodes (Bursaphelenchus xylophilus) aggregated around pupal chambers of Monochamus alternatus in pine wilt-killed trees and the beetle carried many nematodes. However, few nematodes aggregated around pupal chambers of the other beetles, i.e., Acanthocinus griseus, Pissodes obscurus and Trogossita japonica, and these beetles carried few or no nematodes. The higher percentage of M. alternatus pupal chambers with intense blue-stain of wood would cause more nematodes to aggregate around such chambers, as blue-stain fungi are suitable for B. xylophilus propagation.

scholarly journals Monochamus Saltuarius Endangers Pinus tabuliformis Carr. and Carries Bursaphelenchus xylophilus (Steiner and Buhrer) in China

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1051
Author(s):  
Long Pan ◽  
Yongxia Li ◽  
Rong Cui ◽  
Zhenkai Liu ◽  
Xingyao Zhang
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Vector Species ◽  
Pinus Tabuliformis ◽  
Longhorn Beetles ◽  
Average Annual Temperature ◽  
Pine Trees ◽  
Pinewood Nematodes ◽  
And Control

The pinewood nematode (Bursaphelenchus xylophilus) can cause fatal damage to trees and is transmitted by the vector species of the Monochamus genus. In December 2017, pinewood nematodes were found to be harming a large plot of pine trees, Pinus tabuliformis, in a new region with an average annual temperature of 6.7 °C in China. However, the vector insects were unknown and urgently needed to be identified. Hence, in April 2018, we collected wood sections of P. tabuliformis trees that had died from pine wilt disease. All 127 longhorn beetles that emerged from the P. tabuliformis samples were identified as Monochamus saltuarius, and the nematodes they carried were fourth-stage dispersal juveniles of the pinewood nematode. The carrier rate of pinewood nematodes in the M. saltuarius population was 58.3%, and the average carrying capacity was 642.4 ± 89.3. In the same P. tabuliformis plot, 742 M. saltuarius beetles were collected from hormone traps. Our results revealed that M. saltuarius can damage P. tabuliformis and is a new vector species of the pinewood nematode in China. These findings can inform the prevention and control of pinewood nematode damage to pine forests.

scholarly journals Bxy‐fuca encoding α‐L‐fucosidase plays crucial roles in development and reproduction of the pathogenic pinewood nematode, Bursaphelenchus xylophilus

2019 ◽  
Vol 76 (1) ◽  
pp. 205-214 ◽  
Author(s):  
Jia Tang ◽  
Ruoqing Ma ◽  
Najie Zhu ◽  
Kai Guo ◽  
Yiqing Guo ◽  
...  
Keyword(s):  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode

scholarly journals Genetic characteristics of Bursaphelenchus xylophilus third-stage dispersal juveniles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qiaoli Chen ◽  
Ruizhi Zhang ◽  
Danlei Li ◽  
Feng Wang
Keyword(s):  
Fat Metabolism ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Genetic Characteristics ◽  
Highest Weight ◽  
Homologous Genes ◽  
Third Stage ◽  
Highly Correlated ◽  
Oil Red O Staining ◽  
Oil Red O

AbstractThe third-stage dispersal juvenile (DJ3) of pinewood nematode (PWN) is highly associated with low-temperature survival and spread of the nematode. Oil-Red-O staining showed that its lipid content was significantly higher compared with other PWN stages. Weighted gene coexpression network analysis identified that genes in the pink module were highly related to DJ3 induced in the laboratory (DJ3-lab). These genes were arranged according to their gene significance (GS) to DJ3-lab. Of the top 30 genes with the highest GS, seven were found to be highly homologous to the cysteine protease family cathepsin 1 (CATH1). The top 30 genes with the highest weight value to each of the seven genes in the pink module were selected, and finally 35 genes were obtained. Between these seven CATH1 homologous genes and their 35 highly related genes, 15 were related to fat metabolism or autophagy. These autophagy-related genes were also found to be highly correlated with other genes in the pink module, suggesting that autophagy might be involved in the mechanism of longevity in DJ3 and the formation of DJ3 by regulating genes related to fat metabolism.

scholarly journals Chitosan increases Pinus pinaster tolerance to the pinewood nematode (Bursaphelenchus xylophilus) by promoting plant antioxidative metabolism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Nunes da Silva ◽  
Carla S. Santos ◽  
Ana Cruz ◽  
Adrián López-Villamor ◽  
Marta W. Vasconcelos
Keyword(s):  
Phenolic Compounds ◽  
Pinus Pinaster ◽  
Plant Defence ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Nematode Population ◽  
Post Inoculation ◽  
Pinewood Nematode ◽  
Plant Tolerance ◽  
The Moment

AbstractThe pine wilt disease (PWD), for which no effective treatment is available at the moment, is a constant threat to Pinus spp. plantations worldwide, being responsible for significant economic and environmental losses every year. It has been demonstrated that elicitation with chitosan increases plant tolerance to the pinewood nematode (PWN) Bursaphelenchus xylophilus, the causal agent of the PWD, but the biochemical and genetic aspects underlying this response have not been explored. To understand the influence of chitosan in Pinus pinaster tolerance against PWN, a low-molecular-weight (327 kDa) chitosan was applied to mock- and PWN-inoculated plants. Nematode population, malondialdehyde (MDA), catalase, carotenoids, anthocyanins, phenolic compounds, lignin and gene expression related to oxidative stress (thioredoxin 1, TRX) and plant defence (defensin, DEF, and a-farnesene synthase, AFS), were analysed at 1, 7, 14, 21 and 28 days post-inoculation (dpi). At 28 dpi, PWN-infected plants elicited with chitosan showed a sixfold lower nematode population when compared to non-elicited plants. Higher levels of MDA, catalase, carotenoids, anthocyanins, phenolic compounds, and lignin were detected in chitosan-elicited plants following infection. The expression levels of DEF gene were higher in elicited plants, while TRX and AFS expression was lower, possibly due to the disease containment-effect of chitosan. Combined, we conclude that chitosan induces pine defences against PWD via modulation of metabolic and transcriptomic mechanisms related with plant antioxidant system.

Sign in / Sign up

Export Citation Format

Share Document