共查询到20条相似文献，搜索用时 31 毫秒
1.
TheneedlerustofKoreanpine(tbceo3Poriam5bus=vureaeThUm)isacom-lnondiseaseinYichunforestregion.ltmainl}:hamstheneedlesofyoungtrCeswhichareundertheageoffifteen,affectsthegrowthofthemtosomedegree.Thepathogenicfungushadbeenreportedl"'].Inordertoidentifythepathogenand1ifehistoryoftheneedlerustsofKoreanpineandfindouttheoccurringlatvandeffecti\'econtfolmeasure,asystCmaticsurveyx`ascarriedoninYichunforestduringl992-'l994.DISTRIBUTlONANDHARMAccordingtothesurveyofinsectPestsandplantdiscasesin… 相似文献
2.
樟子松疱锈病重寄生菌的分离鉴定 总被引：1，自引：0，他引：1
樟子松疱锈病是樟子松枝干上的主要病害,为利用重寄生菌对樟子松疱锈病进行生物防治,对其病原菌松芍柱锈菌Cronartium flaccidum(Alb.et Schw.)Wint.的重寄生菌进行了分离和鉴定,得到重寄生菌拟枝孢镰刀菌Fusarium sporotrichioides Sherb.、深绿木霉Trichoderma atroviride,并测定ITS序列,获得基因登录号。经显微观察发现接种重寄生菌后锈孢子受到不同程度的破坏,且存在两种不同的作用机理。 相似文献
3.
R. Kasanen 《Forest Pathology》1997,27(4):251-260
The morphology of the aeciospores of the pine stem rust fungi Cronartium flaccidum, Cronartium ribicola and Endocronartium pini, collected from nine locations in Finland, Sweden and Italy, was compared. Surface structures of 900 aeciospores were visually classified using a scanning electron microscope, and dimensions of 1100 aeciospores were measured from micrographs. The data grouping was tested with discriminant analysis. The spores had well-defined smooth areas and annulate warts on their surface. E. pini, C. flaccidum and C. ribicola could not be distinguished by the surface structures of the spores. The grouping of spores by dimensions into sample locations was statistically significant by one discriminant function, while the grouping into species was not. The observed similarities corroborated the current views on the close relationship of C. flaccidum and E. pini. 相似文献
4.
Olga Kozhar Jorge R. Ibarra Caballero Kelly S. Burns Jane E. Stewart 《Forest Pathology》2023,53(3):e12814
The invasive fungal pathogen Cronartium ribicola causes white pine blister rust which is considered one of the most destructive diseases of five-needle (white) pines in North America. The disease has a life cycle that requires two hosts: white pines and Ribes spp., although other non-Ribes species, including Castilleja and Pedicularis, have been demonstrated as alternate hosts as well. Detection of this disease can be difficult because of the ephemeral nature of sporulation on pine hosts with ambiguity in other symptoms, and the alternate hosts for C. ribicola can also be an alternate host for other pine rust species. We used the previously published C. ribicola genome and species-specific real-time PCR assay to develop a field-ready loop-mediated isothermal amplification (LAMP) specific colorimetric assay for this pathogen. Specificity results across regionally identified pine rust pathogens showed the assay is highly specific to C. ribicola and can detect as little as 40 pg of pathogen DNA. We also developed a simple DNA extraction method that works with several tissue types (bark/phloem, aeciospores, and urediniospores/telia) to prepare the DNA samples for the LAMP assay. The DNA extraction and LAMP assay take ~70 min to complete and require a relatively small investment in equipment. This tool enables quick and efficient detection of white pine blister rust. 相似文献
5.
The analysis of random amplified microsatellite (RAMS) markers among aecia of the causal agent of the resin top disease (Peridermium pini) on Scots pine (Pinus sylvestris) suggested that the genetic variation between the populations of this rust fungus is low in Finland. The method used allowed the identification of heterozygotic aecia in two loci, where the degree of heterozygosity was, however, low. The RAMS patterns of the Finnish aeciospores, other aeciospores from Thetford, UK and Cronartium flaccidum from Italy were highly similar suggesting that the autoecious and heteroecious forms of these rust fungi would be genetically closely related. 相似文献
6.
7.
8.
According to the literature the following evidence suggests racial variation in white pine blister rust: changes over site in general level of resistance; interaction of needle spot color types with crosses of western white pine; neutralization of specific resistance reactions; bark reactions and normal cankers on the same tree. 相似文献
9.
10.
The introduction of Cronartium ribicola, the causative agent of white pine blister rust, has been devastating for white pines in North America, including western white pine. Among the observed partial resistance responses to white pine blister rust is a mechanism referred to as difficult-to-infect (DI), which is characterized by lower frequency of infection spots on needles and a lower incidence of branch and stem cankers than susceptible host plants. Parents with the DI trait were selected and bred to produce nine full-sib families. Progeny were propagated and cloned using in vitro techniques in controlled environmental conditions. Explants were inoculated with a single strain of C. ribicola and characterized by using a disease assessment index (DAI), which was used to compare DI full-sib families to several other full-sib families (from Idaho) selected for other partial resistance traits. Most DI families had significantly lower DAI scores and higher epicuticular wax content. When the wax was removed from the surface of needles, the DAI of all full-sib families increased. Scanning electron microscopy revealed that stomata in DI full-sib families are mostly occluded by epicuticular wax. The results of this study suggest that the DI resistance mechanism of western white pine is related to needle surface epicuticular wax, which likely hinders the penetration of stomata by fungal hyphae. The occurrence and magnitude of this trait in the breeding population remains unknown, and special assessment technique for large-scale screening will have to be developed. 相似文献
11.
《Scandinavian Journal of Forest Research》2012,27(1-4):349-357
The blister rust of two‐needle pines in Europe is caused by the rust fungus, Cronartium flaccidum (Alb. Schw.) Wint. There are two races of the fungus: One host‐alternating and another pine‐to‐pine race. The latter race is considered to be more common in northern Sweden. The impact of this rust on growth of Scots pine (Pinus sylvestris L.) was investigated in three selected stands in northern Sweden. Radial stem increment was reduced 40–70% by severe attacks and 20–40% by minor attacks. The reduction of stem volume growth was probably greater. The faster growing trees seemd to be more severely attacked. Trees growing on poor soils appeared to lose almost as much growth capacity from a minor attack as from a severe attack. 相似文献
12.
Loblolly pine (Pinus taeda) seedlings from 12 full-sib families obtained from a six-parent half diallel mating design were challenged in a greenhouse
using two basidiospore inocula of the fusiform rust fungus (Cronartium quercuum f.sp. fusiforme) at extremely high spore density. Each basidiospore inoculum originated from a mixed gall collection of aeciospores obtained
from field-infected trees. Assessments at 4.5 months after inoculation showed that rust disease levels were high for every
full-sib family and were typically above 90% for most full-sib families for both inocula. However, disease (% galled) for
family E by A progeny, even at 9 months post inoculation, was lower, around 75%. A genetic model for interaction of two pairs
of genes was proposed to explain the observed infection levels (% galled) in this diallel based on a gene-for-gene hypothesis.
The putative genotypes of host parents and virulence compositions of mixed inocula were postulated. A bulk-segregant analysis
approach based on phenotype (gall vs. no gall) was used to search for dominant molecular markers associated with the potential
resistance genes in the host parents. A few candidate marker polymorphisms were observed between the gall vs. no gall bulks;
however, none of the candidates appropriately co-segregated with phenotype when tested across the progeny set. An alternative
model involving recessive resistance controlled by a single locus was also considered, but as with the two gene model, no
markers to support the appropriateness of the recessive resistance model were observed. 相似文献
13.
The relative susceptibility to fusiform rust of provenances of 6 European species of pine was tested at Athens, Georgia U.S.A. Needle and stem spots caused by rust were found on the seedlings of all the species and their provenances. Several maritime pine and Aleppo pine seedlings showed particular longitudinal cracks caused by the fungus mycelium in the stem; those of Austrian pine and of Swiss Mountain pine had a violet zone around the cotyledons due to the presence of the fungus mycelium in the needle tissues. If the percentage of galled seedlings is taken into consideration, the test results indicate that Aleppo pine, Austrian pine and Italian stone pine are more susceptible to infection than are maritime pine, Swiss Mountain pine or Scots pine. 相似文献
14.
Woo Kwan-Soo Fins Lauren McDonald Geral I. Wenny David L. Eramian Aram 《New Forests》2002,24(2):113-129
Statistically significant differences were found in 14 needle traits of western white pine (Pinus monticola Dougl.) seedlings grown from the same seed orchard source in the three nurseries in northern Idaho. Traits with significant variation included needle length and width, number of stomatal rows, number of stomata per row, total stomata per needle, adaxial surface area, stomatal density, major axes of stomata, stomatal shape, stomatal area, stomatal occlusion, epistomatal wax degradation, weight of wax per dry weight of needle, and the contact angles of water droplets placed on adaxial needle surfaces. Wax crystallites on needle surfaces were hollow and tubular and the amount of surface wax appeared to be associated with surface wettability. Our results may have important implications for tree improvement programs that require successful inoculation of nursery-grown seedlings with spores of Cronartium ribicola J. C. Fisch. ex Rabenh. to reliably screen white pines for resistance to blister rust. 相似文献
15.
《Scandinavian Journal of Forest Research》2012,27(3):202-207
Abstract Seasonal fruiting and sporulation of cone rusts were investigated in Norway spruce cones during the growing season of 2007, a year after an excellent cone crop and a severe outbreak of rust. Current-year and 1-year-old cones were collected bimonthly to monthly from case-stands in southern and northern Finland and checked for rust fruitbodies. A previously unreported species of rust formed spermogonia and aecia, and sporulated on the cone scales of Norway spruce in two study areas. Morphologically, the rust was distinct from other spruce cone rusts and, based on ultrastructure of aecia and aeciospores, most closely resembled Chrysomyxa ledi. Molecular analysis of the aeciospores confirmed that the rust belonged to the C. ledi/C. rhododendri complex. The rust fruited frequently but only colonized a few scales per cone and presumably had a minor effect on cone development and seed crop. 相似文献
16.
At Florence, Italy, several species of pine were experimentally infected with blister rust. Inoculations were carried out on 3 and 15 months-old seedlings. After antificial and natural inoculation, Brutia, Aleppo, Austrian, Swiss mountain, Maritime and Italian stone pine showed pyenia and aecia. Spotted seedlings of Ponderosa pine showed only mycelium of C. flaccidum in needle and stem tissues. The exotic species seemed to have a very high degree of resistance to blister rust. 相似文献
17.
The aim of this study was to assess the effect and importance of the feeding of the pine top weevil (Pissodes piniphilus) on the germination of Endocronartium pini (syn. Peridermium pini) in Scots pine (Pinus sylvestris), and thus to establish the possibility of the E. pini infection via insect woundings. Germination tests were therefore carried out on current and previous year needle and phloem extracts. Elucidation of the importance of pathogen infection for the insect's feeding preference was also required; for this purpose feeding preference tests were carried out with healthy and infected pine branches using the pine top weevil as a test insect. Weevil feeding increased the germination of E. pini aeciospores on pine extracts. Germination on previous year annual-shoot extracts was lower than that on current year annual-shoot extracts. The advance of the growing season increased this trend, but weevil feeding increased germination on extracts from older annual shoots to the levels found on extracts from current annual shoots. Spores germinated equally well on needle extracts and on phloem extracts. The weevils ate more often on infected branches than on healthy branches. E. pini infections may occur via woundings on branches and weevil feeding may facilitate this. 相似文献
18.
Pathogenicity of cherry‐spruce rust, Thekopsora areolata, was investigated by inoculations with aeciospores from seven Norway spruce, Picea abies, seed orchards that had suffered from successive severe rust epidemics in the 2000s in Finland. Detached leaves of Prunus spp. were inoculated in the laboratory using aeciospores from cones of various ages. In the greenhouse, live Prunus padus plants were inoculated, and possible autoecism of the rust was tested by inoculations of Picea abies seedlings. Thirty‐five spore sources from the seed orchards formed uredinia on Prunus spp. in the laboratory 2 weeks after incubation, but no telia developed. In the greenhouse, uredinia developed on live P. padus, but no rust symptoms, cankers or sporulation were detected on Picea abies. Thus, no evidence of autoecism was observed among the T. areolata populations and therefore all populations, suggesting all those tested from the Finnish seed orchards were heteroecious. 相似文献
19.
R.‐L. Petäistö 《Forest Pathology》2008,38(1):1-15
First‐ and second‐year containerized Norway spruce seedlings were inoculated with conidia of type A (large tree type) and type B (small tree type) of Gremmeniella abietina var. abietina at different times during the summer. The appearance of symptoms after artificial inoculation and natural infection on spruce seedlings were recorded the following spring and compared with the disease symptoms on Scots pine seedlings. The proportion of diseased seedlings after inoculation reached as high as 80%. The susceptible period during the summer began later on the first‐year seedlings than on the second‐year seedlings, and was similar for the pine seedlings. Susceptibility of first‐year seedlings was highest in August and on second‐year seedlings in July. The accumulated temperature sum, relative humidity and height growth for first‐ and second‐year seedlings was assessed. Natural infection in 2002 caused more disease on pine than on spruce seedlings. Experimental thinning of seedlings had no effect on disease incidence. In a preliminary comparison between the ability of A and B types to cause disease in Norway spruce seedlings, type B caused more damage than type A after inoculation. However, type A caused a high disease frequency in other experiments in this study. Symptoms on Norway spruce seedlings often first occurred in the mid‐section of the shoot, and were similar to those observed on pine seedlings: needles turned brown, starting at the needle base, in the spring following inoculation. On first‐year spruce, diseased needles were shed rapidly, in contrast to a slower rate of shedding on first‐year pine seedlings. Pycnidia developed about 2 years after inoculation (on pine 1 year after inoculation). On Norway spruce seedlings the lower part of the shoot, including the lateral shoots, often remained alive. The experiments show that G. abietina can cause disease on containerized Norway spruce seedlings under nursery conditions in Finland. The coincidence of spore dispersal, seedling susceptibility and predisposing factors are important in disease development. 相似文献
20.
INTRODUCTIoNSSPCCiesdiversityistheoneofthreekcysubjcctS(Theglobalweatherchange,speiesdiversltyandsustainedecologysystem)inccologicalandenvironmentalscienceinrecenttenyears.Williams(I943)firstputfonvardsPecicsdiversitywhenhestUdiedtherelationbctx`centhcabundanccandinsectspecicsofLcl,i`mptcra.In6()'s~7()'s-ccologicaIscicn-tistshadgotagreatofachicvementsonsPCcicsdlt'crslti'stud\.Sinccl98()-s.somcscientistsstartcdtostud}'sPCcicsdivcrsityinCl1ina.Thcy'havcgotsolnercsultsol1artl1roPOdcom… 相似文献