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1.
Isabel Carrasquinho Ana Lisboa Maria L. Inácio Elsa Gonçalves 《Annals of Forest Science》2018,75(3):85
Key message
This paper presents a greenhouse study for assessing the genetic variation in maritime pine (Pinus pinaster Aiton) in response to pinewood nematode (Bursaphelenchus xylophilus (Steiner et Buhren) Nickle), which is a causal agent of pine wilt disease. Fifteen out of 96 half-sib families were selected as less susceptible. This experiment is an important first step for creating a resistance breeding program.Context
Pine wilt disease is caused by the pinewood nematode (Bursaphelenchus xylophilus (Steiner et Buhren) Nickle), a quarantine pest, and is a concern to maritime pine (Pinus pinaster) in Portugal due to its economic, environmental, and social impacts. This disease is regarded as a major threat to European forests.Aims
This paper aimed to evaluate the genetic variation in maritime pine families that were inoculated with pinewood nematode, identify the most resistant families, and establish the guidelines for a resistance improvement program.Methods
Two-year-old half-sib progenies obtained from 96 plus trees were inoculated. The plants were monitored for survival on four different dates. The statistical analysis followed the mixed model theory.Results
Genetic variability of the susceptibility to pine wilt disease was observed. At 157 days after inoculation, the 15 highest genetic ranking families out of 96 were selected, having a predicted survival mean of 15.6% instead of 11.0% on average for the all 96 families.Conclusion
This study allows for the implementation of an improvement program to help control pine wilt disease.2.
Adult trees of Pinus armandii var. amamiana (PAAm) and P. thunbergii grown in the field were inoculated with 100000 or 1000 of the nematode Bursaphelenchus xylophilus to evaluate their susceptibility to pine wilt disease. PAAm trees inoculated with 100000 nematodes started to show disease symptoms 2 weeks after inoculation, and all died within 29 weeks. Although the PAAm trees inoculated with 1000 nematodes tended to show delayed disease symptoms compared with those inoculated with 100000 nematodes, all of them died within 33 weeks after inoculation. All P. thunbergii trees inoculated with 1000 nematodes had died 6 weeks after inoculation. In the nematode-inoculated PAAm trees, death of branches distal to the nematode inoculation site was the first visible symptom, followed by the systemic discoloration of needles, whereas the whole tree wilted simultaneously in P. thunbergii trees. In nematode-inoculated PAAm trees, the period from inoculation to death was longer than that in P. thunbergii. These results suggest that adult PAAm trees are susceptible to pine wilt disease, but are less vulnerable than P. thunbergii. 相似文献
3.
Anura Pushpakumara Rathnayake Hirofumi Kadono Satoru Toyooka Makoto Miwa 《Journal of Forest Research》2007,12(6):393-402
This study presents the effects of short-term ozone exposure on the nano-scale growth behavior of the fine roots of Pinus densiflora (Japanese red pine) seedlings. Root elongation measurements were obtained in nanometers for very short (sub-second) time
intervals by using the optical interference method called statistical interferometry, developed by the authors. Three categories
of P. densiflora seedlings were investigated; two categories were infected with ectomycorrhiza of Pisolithus sp. (Ps) and Cenococcum geophilum (Cg), while the third was without any fungal infection. In experiments, two points on a root with a separation of 3 mm were illuminated
by laser beams and the elongation was measured continuously by analyzing speckle patterns successively taken by a CCD camera.
The ectomycorrhizal fungi-infected and uninfected seedlings were exposed to ozone at concentrations of 120 and 240 ppb for
periods of 1, 3, or 5 h in separate treatments. The root elongations of P. densiflora seedlings were measured before and immediately after the each ozone treatment and then the root elongation rates (RER) were
determined for growth-measurement periods of 5.5 s and 9.5 min. From the measurements obtained for 9.5 min, we found that
the RERs of uninfected and Cg-infected seedlings were reduced by 42 and 18%, respectively, after 5 h of exposure to 120 ppb ozone compared with that before
exposure, while the reduction in RER of Ps-infected seedlings was not significant. When the concentration of ozone was increased to 240 ppb, the RERs of Ps-infected and Cg-infected seedlings were reduced by 32 and 44%, respectively, after exposure for 5 h, while the reduction in RER of uninfected
seedlings was 59%. These observations prove that the non-mycorrhizal seedling roots are more sensitive to ozone stress. From
this study, we found that the RERs of both mycorrhizal and non-mycorrhizal seedlings apparently fluctuated throughout the
measurements, even within a few minutes. 相似文献
4.
Yoichi Kishi 《Journal of Forest Research》1999,4(4):287-290
The total area ofPinus densiflora andP. thunbergii forests in Ibaraki Prefecture in 1978 was 65,200 ha, which decreased to 30,300 ha by 1985 mainly due to pine wilt mortality
caused byBursaphelenchus xylophilus. This damage has also continued thereafter. To estimate the survivability of pine trees in Ibaraki Prefecture, pine tree
mortality has been studied in eight experimental forests for over 20 years, and ground surveys throughout the Prefecture were
also conducted in 1995. Survival in the experimental forests corresponded well to the results of ground surveys. Pine forests
remained as pure stands if control measures were undertaken or if they were located in cool areas. In warm areas where no
control was undertaken, most of the pine forests disappeared and only a few pine trees remained in mixed forests, while on
dry soils no mature or old pine trees survived. Since surviving pine forests are often cut for wood utilization,P. densiflora andP. thunbergii may decrease in area to become rare species in the future unless controls are applied and/or reforestation with resistant
pines is carried out.
A part of this paper was orally presented at the 108th Annual Meeting of the Japanese Forestry Society (1997). 相似文献
5.
Seedlings from a wide array of 23 species, varieties,and geographic races were screened for resistance topitch canker using artificial inoculation in agreenhouse. Seed to represent these taxa weregenerally collected in natural stands. In addition,seedlings from 79 families of P. radiata fromcommercial populations from Chile and New Zealand werescreened in a separate experiment. There was littlevariation in resistance among the commercial P.radiata families, with over 98% mortality. Similarresults were obtained with native P. radiatapopulations. All close relatives of P. radiata(sub-section Patula) were very susceptible. However,a number of closed-cone pine species (specifically,from sub-section Oocarpa) were generally veryresistant, with survival approaching 100%. Inaddition, in P. oocarpa, P. jaliscana, and P. tecunumanii from low elevation provenances anextremely high frequency of trees suffered no apparentdamage from the pathogen (92%, 85% and 80%,respectively). 相似文献
6.
Katsumi Togashi Kaori Aida Katsunori Nakamura Takao Horikoshi Fumiki Takahashi 《Journal of Forest Research》1997,2(1):39-43
To evaluate the effect of adjacent tree species on the susceptibility of Japanese black pine (Pinus thunbergii) to pine wilt disease, an inoculation experiment was conducted usingP. thunbergii seedlings potted with seedlings of six tree species,i. e. Alnus sieboldiana, Eurya japonica, Lespedeza bicolor formacutifolia, Pinus thumbergii, Robinia pseudo-acacia andSarothamus scoparius. About ten months after planting, they were inoculated with the pinewood nematode (Bursaphelenchus xylophilus) in early July 1992. After that, the proportion of pine seedlings with completely discolored foliage increased more quickly
when the seedlings were potted withR. pseudo-acacia, S. scoparius orA. sieboldiana than when potted withP. thunbergii, L. bicolor orE. japonica. At the end of the study period, 17 weeks after inoculation, it reached 90.6%, 90.0%, 87.5%, 72.7%, 63.3%, and 59.4% when
the pine seedlings were potted withR. pseudo-acacia, S. scoparius, A. sieboldiana, P. thunbergii, L. bicolor andE. japonica, respectively. This indicated that the susceptibility ofP. thunbergii seedlings to pine wilt disease was influence by the species of adjacent trees. 相似文献
7.
Six pine species or hybrids were tested for susceptibility to pitch canker caused by Fusarium circinatum. Pinus densiflora, Pinus thunbergii, Pinus x rigitaeda (Pinus rigida × Pinus taeda), P. rigida × P. x rigitaeda, Pinus echinata and Pinus virginiana were inoculated with three spore loads (50, 500 and 5000 per tree) of F. circinatum. External symptoms, lesion length, and the frequency of reisolation of the fungus were investigated. External symptoms were greatest in P. echinata, followed by P. virginiana, however, P. densiflora was not susceptible to F. circinatum. Based on mean lesion lengths, the six pine species or hybrids differed significantly (p < 0.01) in susceptibility to pitch canker. Pinus echinata sustained the longest lesions, whereas P. densiflora sustained the shortest lesions. The effect of inoculum density was not significant among three spore treatments within species (p = 0.17), although lesion length was slightly greater at higher spore loads over all pine species. The fungus was reisolated from inoculated stems of all pine species tested, even on trees showing little or no damage from the disease. Additional studies are needed to further explore the basis for resistance to pitch canker. 相似文献
8.
Jyrki Tomminen 《Forest Pathology》1993,23(4):236-243
The objective of the study was to determine the role of Finnish Bursaphelenchus mucronatus as a possible pathogen in Scots pine, Pinus sylvestris, under Finnish ambient weather conditions. Small seedlings and young field grown trees were used as inoculation targets. The results suggested the nematode being of minor importance as a tree pathogen in Finland. 相似文献
9.
Inoculation experiments were performed in order to evaluate the virulence of Gremmeniella abietina isolates from Spain on the main pine species planted in the Iberian Peninsula, as well as the influence of seedling age on this virulence. Two different experiments were carried out with four isolates of G. abietina from Spain. The greenhouse experiments consisted of seedling inoculations. One‐ and 2‐year‐old seedlings of the following five pine species were used: Pinus halepensis, Pinus pinea, Pinus pinaster, Pinus sylvestris and Pinus uncinata; also, 1‐year‐old seedlings of P. nigra were inoculated. The relative necrosis length (RNL) caused by the pathogen after 130 days was used as a response variable. The laboratory experiments were performed on 2‐ to 6‐year‐old internodes of the above pine species excluding P. uncinata. The necrosis length after 6 weeks of incubation was measured. The results have shown that all G. abietina isolates were pathogens on seedlings of these six pine species and seedlings of P. halepensis were consistently the most susceptible ones, although it is important to take into account that all the isolates used in the present work were isolated from P. halepensis, the only pine species in Spain where G. abietina has been recovered up to now. The susceptibility of the other pine species depended on the age of the seedlings. 相似文献
10.
To determine why pine wilt disease caused by the pinewood nematode (Bursaphelenchus xylophilus) recurs in the same pine stand even after thorough eradication of dead pine trees, the amount of oleoresin exudation from artificial wounds was measured from 72 Pinus koraiensis trees, highly susceptible to this disease, for 4 years. The amount of exuded oleoresin was rated from 0 to 4. All values obtained for each tree were summed at each measurement; thereby a cumulative curve was drawn to monitor the physiological condition of each test tree. Cumulative curves suggest that some pine trees that died had already been infected in the previous year or earlier and then had survived without any visible symptoms. If cessation of oleoresin exudation delays, and overlaps with activity of Monochamus alternatus, the vector beetle of pinewood nematodes, in the following season, such trees can be referred to as latent carriers or asymptomatic carriers. They could play a significant role as attractants for M. alternatus that could then transmit B. xylophilus to neighboring trees. Behavior of M. alternatus caged with several pine seedlings, only one of which acted as an asymptomatic carrier of B. xylophilus, confirmed this idea. The presence of asymptomatic pine trees, which harbored B. xylophilus nematodes or had reduced annual elongation, near stumps of newly dead trees in the study stand also substantiated this hypothesis. 相似文献
11.
Pinus densiflora f.umbraculifera, commonly known as utsukushimatsu, is a distinctively shaped form of Japanese red pine whose growth is restricted to a forest
stand in Shiga Prefecture, Japan. The inheritance mode of morphological characteristics of utsukushimatsu was studied to preserve
the genetic resource of this pine. As previously reported, F1 trees grown from open-pollinated seeds harvested from trees inhabiting the native stand showed two phenotypes: one resembling
utsukushimatsu, which produces multiple trunks, and the other resembling normalP. densiflora, which produces one or a few trunks. In the present study, controlled pollination was carried out using F1 and normalP. densiflora trees. Segregation ratios of the two phenotypes observed in the F2 population showed that the morphological characteristics of utsukushimatsu are inherited recessively. This suggests that
the mutation of one gene or a few closely linked genes controls the morphological characteristics of utsukushimatsu. Since
multiple trunk formation of utsukushimatsu might be related to a loss of lateral bud inhibition, it follows that a simple
gene mutation breaks apical dominance inP. densiflora. 相似文献
12.
Dai Kusumoto Takashi Yonemichi Hiroki Inoue Tomonori Hirao Atsushi Watanabe Toshihiro Yamada 《Journal of Forest Research》2014,19(2):285-294
Pine wilt disease caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, has been epidemic and has had disastrous impacts on pine forests and forest ecosystems in eastern Asia. Many pine species in this area are susceptible to this disease. Pinus thunbergii is particularly susceptible. In Japan, tree breeders have selected surviving trees from severely damaged forests as resistant candidates, and have finally established several resistant varieties of P. thunbergii. However, this breeding procedure requires much time and effort due to the lack of physiological and phenotypical information about resistance. To investigate the resistance mechanisms of selected P. thunbergii, we compared histochemical responses, tissue damage expansion, and PWN distribution in resistant and susceptible clones of P. thunbergii after PWN inoculation. The results suggested that the mechanisms of resistance are as follows: damage expansion in the cortex, cambium, and xylem axial resin canals are retarded in resistant trees soon after inoculation, probably due to the induction of wall protein-based defenses. Suppression of PWN reproduction was particularly caused by inhibition of damage expansion in the cambium. The slow expansion of damage in each tissue provides time for the host to complete the biosynthesis of lignin in the walls of cells that surround the damaged regions. This lignification of cell walls is assumed to effectively inhibit the migration and reproduction of the PWNs. The mechanism of initial damage retardation is presumed to be a key for resistance. 相似文献
13.
To elucidate the synergetic effects of acid rain on the development of pine wilt disease, we measured the sap flow rate in the stems and the chlorophyll content in the needles of 10‐year‐old Japanese black pine trees, Pinus thunbergii and 12‐year‐old Japanese red pine trees, Pinus densiflora, after exposure to simulated acid rain (SAR, pH 3) or tap water (TW, pH 6.3) as a control. The heat pulse method was used for the estimation of the sap flow rate. No apparent difference was found in the sap flow rate between the trees exposed to SAR and TW, but the chlorophyll content of needles at the end of the treatment was significantly higher in the trees exposed to SAR than in those exposed to TW. When the pinewood nematode, Bursaphelenchus xylophilus, the causal agent of pine wilt disease, was inoculated onto the Japanese black pines that had been exposed to SAR repeatedly for 1 year, the period to death was shortened. Japanese red pines that had been exposed to SAR for 2 years, however, did not show any development of symptoms after the nematode inoculation, suggesting that acid rain only affects pine wilt disease slightly, if at all. 相似文献
14.
Physiological process of the symptom development and resistance mechanism in pine wilt disease 总被引:4,自引:0,他引:4
Kenji Fukuda 《Journal of Forest Research》1997,2(3):171-181
Pathophysiological changes during the symptom development of pine wilt disease are reconsidered from recent investigations.
The symptom development is divided into two stages: the early and the advanced stages. In the early stage, small number of
nematodes migrate in cortex, then in xylem of the stem, and induce denaturation and necrosis of parenchyma cells. These changes
in parenchyma are regarded as defense reactions of pines which result in terpene synthesis in xylem cells and embolism in
tracheids. Such changes in the early stage can be induced in both susceptible and resistant pine species by either virulent
or avirulent isolates of pinewood nematode (Bursaphelenchus xylophilus), or byB. mucronatus. No change occur in physiological status of leaves, and nematode reproduction is suppressed during this stage. Pine trees
can survive if symptom does not progress from this stage. The symptoms of the advanced stage usually occur only in susceptible
pines infected by virulent nematode isolates. At the beginning of the advanced stage, enhanced ethylene production by stem
which coincides with cambial destruction occurs, and results in embolism of the outermost xylem in the portion. The embolism
causes decrease in leaf water potential and cessation of photosynthesis. After cessation of photosynthesis, symptoms develop
drastically with a burst of nematode population. There seems to be some unknown mechanism which suppress nematode reproduction
and invasion to the cambial zone. This mechanism is thought to be photosynthesis-dependent, so that in photosynthesis-decrased
conditions, even avirulent nematodes can multiply and invade cambium to induce tree death. Water stress in hot and dry summer
should accelerates symptom development from the early to the advanced stage through such decrease of photosynthesis-dependent
“cambial resistance”. 相似文献
15.
White pine blister rust caused by Cronartium ribicola is a damaging non‐native disease of five‐needled pines in North America. Efforts to control the disease and mitigate damage to date have been only somewhat effective. Recent efforts to improve the health of eastern white pine and reestablish the tree as a dominant species in the North Central United States have focused on identification and propagation of disease‐free eastern white pine (Pinus strobus) growing in areas with a high incidence of blister rust. Many of these selections have been shown to resist infection following artificial inoculation with C. ribicola. In this study, 13 eastern white pine families derived from controlled pollination of selections previously determined to possess putative resistance as well as susceptible selections were inoculated with C. ribicola. Mortality data from inoculation studies show superior survivability in three families with over 60% of seedlings able to survive the 52 week post‐inoculation monitoring period compared to 0–10% survival of the most susceptible families. Primary needles were collected for histological analysis from all inoculated families 4 weeks after inoculation and from selected families 6.5 weeks and 38 weeks after inoculation. Histological observations of infection sites show distinct resistance reactions in the families more likely to survive infection based on mortality data. Analysis of the reactions in susceptible families revealed extensive hyphal colonization of the vascular bundle and adjacent mesophyll cells that appear uninhibited by tree responses. In resistant families, collapsed cells adjacent to infection sites, heavy deposition of phenolic compounds and abnormal cell growth were documented more frequently and appear to play an integral role in the ability of these eastern white pine families to impede growth of C. ribicola in primary needle tissue. 相似文献
16.
The pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer, J. Agric Res. 48, 1934, 949), Nickle (J. Nematol. 2, 1970, 375), is the causative agent of the pine wilt disease and causes serious damage to pine forests around the world. During a survey for the pinewood nematode, four other Bursaphelenchus species (Bursaphelenchus mucronatus, B. sexdentati, B. anamurius and B. vallesianus) were isolated from wilted pine trees in Turkey. To understand the effects of these Bursaphelenchus species on wilting of pine trees, a study was conducted under greenhouse conditions. Two‐year‐old seedlings of three pine species (Pinus nigra, P. brutia and P. pinea) and one cedar species (Cedrus libani) were used. Fifteen seedlings of each species were inoculated with nematodes and 10 seedlings of each species served as controls. The inoculum densities used for each seedling contained approximately 1000 (±100) nematodes of all life stages in 0.25 ml of distilled water. The first wilting symptoms were observed in the fifth week in all pine species but not in the cedar seedlings. All seeding mortality occurred between the 5th and 13th weeks of the study; no mortality was observed outside of this period. The most pathogenic nematode species was B. mucronatus, closely followed by the other species. The most susceptible seedling species was P. nigra, and C. libani was the most resistant species. 相似文献
17.
The Japanese black pine (Pinus thunbergii) is highly susceptible to pine wilt disease caused by the pine wood nematode (PWN; Bursaphelenchus xylophilus). To cope with this disease, researchers and tree breeders selected PWN‐resistant individuals in a previous breeding program. In an attempt to understand the mechanisms of resistance in the Japanese black pine, we created four LongSAGE (serial analysis of gene expression) libraries. A total of 20 818 tags were studied, including 5194 tags from a PWN inoculated resistant pine, 5218 a non‐inoculated resistant pine, 5194 an inoculated non‐resistant pine, and 5212 a non‐inoculated non‐resistant pine. The analysis of the libraries indicated that 14 tag species were significantly up‐regulated (e.g., pathogenesis‐related proteins 2 and 4, osmotin, lipoxygenase, and chalcone synthase), and nine were down‐regulated (eukaryotic translation initiation factor SUI1, translationally controlled tumor protein, and xyloglucan endotransglycosylase) by the PWN inoculation in both the resistant and non‐resistant pines. On the other hand, 38 tag species were significantly expressed at a higher level only in the resistant pine (catalase, dienelactone hydrolase family protein) and 25 were expressed at a higher level in the non‐resistant pine (pathogenesis‐related proteins 1, 2, and 3, and leucoanthocyanidin dioxygenase). These differentially expressed genes are presumed to reflect some of the differences between the resistant and non‐resistant pines. Our results provide valuable information on the complex responses induced in the resistant and non‐resistant pine trees in response to PWN invasion. 相似文献
18.
Junichi Kikuchi Souichirou Iida Tamio Akema Kazuyoshi Futai 《Journal of Forest Research》1996,1(1):37-40
The process of decrease in seedlings of Japanese red pine (Pinus densiflora Sieb.et Zucc.) and the effect of litter and humus layers on the mortality were studied in their stand and adjacent bare land. After
the rainy season, only small number of individuals died in the bare land but more seedlings died in the forest. The number
of seedlings killed by drought was greater in the forest than in the bare land. The population of naturally occurring current
year seedlings was larger in the forest than in the bare land, but that of 1- to 5-year-old seedlings was smaller. Severe
summer drought exceeding the permanent wilting point was observed only in the forest F-H horizon where greater part of seedling
roots distributed, this may be one of major mortality factors. Inhibitory substances to seedling growth in fresh fallen pine
needles were also suggested. 相似文献
19.
When pine trees are invaded by pine wilt diseases, the severely infected pine trees will die and fall down, or they will be
removed when found to be damaged by the disease. It gives rise to the invasion of other species in these empty niches originally
occupied by pine trees, i.e., competing surrounding trees or understory shrubs will invade the empty niches during the following
years. As a result, the spatial distribution and pattern of the main tree species in a pine forest will change, and a niche
variety in the main population will occur. In the end, the direction of the succession and restoration of the pine forest
ecosystem will be affected. In our study, a Pinus massoniana forest with the dominant shrub, Pleioblastus amarus, was invaded by pine wood nematode and was clear cut. Selecting this community as our research object, we studied the effect
of the invasion of the pine wood nematode on the growth of the dominant shrub, P. amarus, in this Pinus massoniana forest. Our results show that, after the attacked pine trees were removed, the niche was occupied by Pleioblastus amarus and other shrubs, which benefited the growth of P. amarus to its climax. Growth of P. amarus at the climax stage was greater compared with the unhealthy pine forest and the control group. 相似文献
20.