排序方式： 共有35条查询结果，搜索用时 93 毫秒
21.
Tania Manzanos Glen R. Stanosz Denise R. Smith Jannes Muenchow Patrick Schratz Alexander Brenning Ana Aragons Eugenia Iturritxa 《Forest Pathology》2019,49(1)
Diplodia sapinea and Diplodia scrobiculata are opportunistic pathogens of Pinus species. Several studies about taxonomy, impact and epidemiology of these fungi have been conducted in previous years, which have provided useful information and have raised new issues. These diseases produce a considerable impact on plantations resulting in significant economic losses. The main aims of this study are to increase the knowledge of the potential of genetic exchange and the relative aggressiveness of these organisms that can persist in healthy tissues of asymptomatic trees. A collection of 250 isolates among which are 149 strains collected from Pinus radiata plantations in Basque Country (Spain) and 101 strains from different countries was included in this work. Mating type ratios were analysed and compared using the structure of the MAT locus (MAT1‐1‐1 and MAT1‐2‐1). Inoculations of Pinus radiata seedlings were performed in a biosafety greenhouse (P2) to confirm pathogenicity of isolates and compare their aggressiveness. The frequency of occurrence of both idiomorphs of D. sapinea in Basque Country isolates was close to 1:1, however, for collection of isolates of this fungus from around the world, the ratio was 1:2. Furthermore, the spatial distribution of the two mating types in the Basque Country was random. Despite no detection of a sexual state, these results could suggest sexual reproduction behaviour. The pathogenicity of all strains in the collection was confirmed. Although aggressiveness (in terms of lesion lengths resulting from inoculation) varied greatly, no statistically significant effects of MAT type or pathogen species were detected. 相似文献
22.
从自然发病的柑橘果实表面分离出柑橘黑色蒂腐病菌(Diplodia natalensis Evans),对其生物学特性研究的结果表明:不同培养基对菌落形态、菌丝生长速率及产孢量都有很大影响,其中以马铃薯蔗糖培养基菌丝生长旺盛,生长速度最快,产孢量最大。病原菌适宜的生长及产孢温度为25~30℃,最适温度为30℃;光照条件对病菌的生长及产孢没有显著的影响;病菌的致死温度在75℃左右,在测试的常用化学药剂中,以咪鲜胺对其抑制效果最好。 相似文献
23.
对从云南澳洲坚果速衰病株上分离的色二孢属(Diplodia sp.)和腐霉属(Pythium sp.)D.13、P.01菌株形态进行了描述;同时通过对澳洲坚果苗根系的接种试验证实,两种真菌是云南澳洲坚果速衰病的致病病原菌。 相似文献
24.
25.
Climate change poses severe pressures to European conifer forests. Using non-native tree species, such as Douglas fir (Pseudotsuga menziesii), is one proposed strategy to circumvent adverse effects for forest management. However, novel forest health risks can impair the cultivation of non-native trees. In 2022, we observed large Douglas fir trees (approximately 40–50 years old, diameter at breast height (dbh) 21–41 cm) that had recently died in spring or summer 2022 in three forest stands in Eastern Austria. Intensive resin flow, blue-staining of the sapwood and the absence of bark- and wood-boring insects indicated a fungal infection. Isolations from blue-stained sapwood of the dead trees consistently yielded cultures of the opportunistic pathogen Diplodia sapinea. In a greenhouse wound inoculation experiment, seven D. sapinea isolates obtained from Douglas fir caused phloem necrosis, blue-staining of sapwood and mortality and thus displayed pathogenicity towards seedlings of both Ps. menziesii and its common host, Scots pine (Pinus sylvestris). Diplodia sapinea produced significantly longer areas of blue-stain as well as higher and faster mortality in Ps. menziesii compared to P. sylvestris. We conclude that D. sapinea substantially contributed to the death of seven of the 13 examined large Douglas fir trees. While this fungus has been described as a pathogen of young Douglas fir trees before, this is the first report that it can potentially kill large individuals of this conifer species under drought conditions. Thus, our results indicate that D. sapinea could represent a severe threat to the cultivation of Ps. menziesii in European forestry. 相似文献
26.
27.
Sawssen Hlaiem Islem Yangui Olfa Ezzine Gianni Della Rocca Sara Barberini Roberto Danti Mohamed Lahbib Ben Jamâa 《Forest Pathology》2023,53(5):e12824
Decline phenomena of shrub species such as Quercus coccifera and Retama raetam have occurred throughout Tunisian forests since 2012. These evergreen shrubs have long been regarded for their medicinal and ecological interests. Therefore, their preservation as valuable forest resources is of great interest. However, information regarding aetiology of this disease is still scarce. Hence, the aim of this study was to identify and characterize the causal agents associated with disease symptoms in two Tunisian forests. Thirty-eight isolates were obtained from symptomatic Q. coccifera and R. raetam twigs. Morphological characterization and phylogenetic analysis of the internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene cluster and partial sequence of the translation elongation factor 1-alpha gene (tef1-α) allowed the identification of three Diplodia species namely Diplodia africana, D. seriata and D. pseudoseriata. Our findings revealed that the incidence of Diplodia species was significantly correlated to the altitude, the temperature and the rainfall. Pathogenicity test showed that all Diplodia isolates are pathogenic. However, D. africana revealed to be the most aggressive species toward R. raetam. These findings were the first record of D. seriata as fungal pathogen associated with Q. coccifera dieback and D. pseudoseriata and D. africana on R. raetam in Tunisia. 相似文献
28.
Nicholas J. Brazee Isabel A. Munck Kelsey McLaughlin Savannah Ferreira Nicole Keleher 《Forest Pathology》2023,53(4):e12822
The 2015–2018 outbreak of spongy moth (Lymantria dispar) in southern New England initiated a severe oak decline and mortality event. While defoliation was a primary driver, increased secondary pest and pathogen activity contributed to decline and death. Following this large defoliation event, Diplodia was frequently recovered from northern red oaks (Quercus rubra) with serious outbreaks of twig cankering. Given the many recent reports of Diplodia corticola on oak in eastern North America, it was presumed to be the causal agent. To confirm, a limited survey was conducted from five states in the region (Maine, Massachusetts, New Hampshire, New York, and Vermont). Based on ITS, tef1 and tub2 sequences generated from 28 isolates collected primarily from northern red oak, Diplodia gallae, two potentially novel Diplodia species and Diplodia sapinea were identified. Surprisingly, D. corticola was not found in this study. ITS sequences alone failed to discriminate among isolates of D. gallae and D. corticola, creating uncertainty over previous reports of D. corticola in eastern North America. Only a combined ITS + tef1 dataset successfully distinguished D. gallae and D. corticola along with two other closely related species that also occur on oak (Diplodia quercicola and Diplodia quercivora). Additional cankering and endophytic fungi (Coryneum, Dendrostoma, Gnomoniopsis, Pestalotiopsis and Tubakia) were also found on symptomatic oaks in the region. Identification of Diplodia isolates from non-Quercus hosts also detected Diplodia neojuniperi on Juniperus chinensis and Microbiota decussata, which has not been reported previously in North America. 相似文献
29.
火炬松,湿地松抗松枯梢病,松针褐斑病种源和个体选择的研究 总被引：3，自引：0，他引：3
南京老山林场火炬松、湿地松种源试验林在１０ａ生时（１９９１年）开始感染松枯梢病和松针褐斑病,病情日趋严重,在１３ａ生（１９９４年）和１５ａ生（１９９６年）时两次重复测定感病和生长变异,火炬松不同种源感病和生长变异均极显著,两者间及年度间相关极显著。按照选择指数的大小选出抗病、生长优良种源４个即９号（佛罗里达·纳索）,１０号（路易斯安那·利文斯通）,１２号（阿拉巴马·埃尔卡拉）和１９号（佐治亚·爱克特）,其选择指数比平均值大２１．４３％～４８．１０％,感病指数低３３．７１％～４９．５３％,树高大７．３２％～１３．５２％,胸径大７．５０％～１７．１９％。同时选出两年重复测定均优良的单株４０多株（占总株数６．７％左右,其中优良种源占５０％）,其感病级别０～Ⅰ级,生长量比平均值大１０％以上。湿地松种源间感病变异不显著,生长虽然有一定变异,但两者相关不显著。选择主要在个体间进行。已选出并经两年重复测定均优良的单株２０多株（占总株数３．３％左右）,其感病级别为０～Ⅰ级,生长量比平均值大１０％以上。 相似文献
30.
在室内离体条件下,对不同日龄的棉铃用孢子液浸铃法接种铃疫病菌、黑果病菌和炭疽病菌。结果表明,不同日龄的棉铃抗病性表现了较大差异,其病铃率和病情指数以开花后 １０ ｄ 左右的棉铃最低,其次是 １５ ｄ 的棉铃,２５ ｄ 的棉铃表现也较低,而蕾、幼龄（５ ｄ 左右）和高龄（３５ ｄ 以上）的棉铃接种后,病铃率和病情指数均较高。此外,铃疫病菌采用菌丝块贴铃法,黑果病菌和炭疽病菌采用孢子液浸铃法,在室内离体条件下对中棉 １０、中棉 １２、岱 １５、盐棉 ４８、苏棉 １ 号、泗棉 ２ 号、苏农 ８２０１ 等 ７ 个棉花品种（系）进行了抗病性测定。结果表明无免疫或高抗品种,但不同品种对这三种铃病的抗病性存在着较大差异。对铃疫病抗性较好的为泗棉 ２ 号,其次为盐棉 ４８、中棉 １２。对黑果病抗性较好的有岱字棉 １５、泗棉 ２ 号和中棉 １２。对炭疽病、无伤接种时表现较好的为岱字棉 １５,其次为中棉 １２ 和泗棉 ２ 号。 相似文献