淡竹竹秆锈病发生危害调查及防治试验

2001-2004年调查了淡竹Phyllostachys glauca竹秆锈病Stereostratum corticioides在河南省洛宁县的发生危害情况,开展了药剂防治试验.结果表明,该病在湿度大、光照弱的竹林发病重,冬孢子堆主要分布在淡竹1 m以下部位.1-2月人工刮除冬孢子堆对新发生的竹秆锈病有良好控制效果,10月上旬和次年3月下旬用20%粉锈宁5倍液2次涂抹冬孢子堆,防治效果90%以上.     

煤酚皂防治淡竹秆锈病研究初报

应用煤酚皂溶液(含煤酚50％),配成15％的浓度,在竹秆锈病冬孢子堆产生后期的3月中下旬,于病部及其周围涂秆2次,防治效果达96％以上。该法应用方便,安全无药害,成本低,便于推广应用。     

云杉叶锈病化学防治试验

通过不同药剂对云杉叶锈病的防治试验表明：２０％三唑酮乳油、２０％萎锈灵乳渍５００倍液对云杉叶锈病的防治效果分别为８４．６％，８１．０％；在２种药液中各加１ｇ／Ｌ的衣粉或明胶后，其防治效果均在９０％以上，安林Ⅰ号，Ⅱ号烟剂的防治效果分别为４２．０％，４１．７％。采用２０％三唑酮乳油，２０％萎锈灵乳油５００倍液对转主寄主冬孢子堆进行喷雾，冬孢子堆枯萎率分别为８８．０％、９０．７％。     

竹子锈病防治试验初报

竹子锈病(竹杆锈病)(Ｓｔｅｒｅｏｓｔｒａｔｕｍｃｏｒｔｉｃｉｏｄｅｓ)又称竹褥病,危害淡竹、刚竹、桂竹等竹种。在我国发生较为广泛。病害多发生在竹杆中、下部或基部,发病严重时,竹杆中上部甚至小枝也会被害。每年11月至翌年春天病部产出土红色至棕黄色的冬孢子堆。?..     

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煤酚皂防治淡竹秆锈病研究初报(陈森等,《江苏林业科技》,1989,16(3).32—33) 应用煤酚皂溶液(含煤酚50％)稀释成10％、15％、20％三种浓度,在3月中下旬竹秆锈病Stere-cstratum coticiodes冬孢子堆产生后,用油漆刷涂刷病部及周围,6月份调查15％浓度涂刷2次防治效果可达95％以上。其作用机理可能是煤酚渗入病菌细胞、使胞壁增厚,原生质浓缩变形,失去生命。该     

竹杆锈病菌冬孢子堆的存在对夏孢子产生的作用及夏孢子的孕育过程

根据对竹杆锈病菌冬孢子堆的6种处理及夏孢子堆孕育过程的显微镜观察结果表明,冬孢子堆的存在对夏孢子的产生有保护和促进作用,这为及时杀灭冬孢子堆,切断浸染源防治竹杆锈病提供了理论依据。     

落叶松褐锈病的综合防治

落叶松褐锈病是危害落叶松的重要病害。1病原落叶松褐锈病由担子菌亚门的落叶松拟三胞锈菌引起,该菌为同主寄生菌,在落叶松上能够完成发育循环。2发病症状发病初期,叶片尖端或近中部出现退绿小斑,逐渐扩大,到6月下旬~7月上旬在叶背面形成夏孢子堆,直到9月中旬仍可产生。夏孢子堆初寄生于叶表皮下,奶油色或赭黄色形成圆小丘状隆起,叶表皮夏孢子堆破裂后露出铁锈色至血红色的粉状物,夏孢子成熟后飞散,最后在夏孢子原基处留下痕迹,这时在叶片上形成段斑,8~9月在叶背面产生3~5个黑褐色凸起于叶表面的小粉堆,即冬孢子堆。随着病害的发展,冬孢子堆…     

浙江竹秆锈病的观察研究

竹秆锈病(Stereostratum corticioides (Berk et Br.)Magnus)又称竹褥病。七十年代以来,江、浙一带的竹秆锈病有所蔓延,病情逐渐加剧,许多地方的竹林已到毁灭的地步。对该病进一步深入研究,寻求彻底的防治措施十分必要。据定点多年观察,该病多发生在竹秆的下部或基部,严重的蔓延至竹秆的上部或枝条上,甚至发生在竹丛枝病的枝条和地面的跳鞭上。病害的冬孢子堆、夏孢子堆、黄斑三个时期较为分明,以往人们对黄斑这个症状往往忽视。竹秆上病斑多时,将诱发其它竹子秆基病害或全株死亡。经接种试验证明,病菌的冬孢子一担孢子不侵染竹秆和竹笋。夏孢子在5～6月产生释放,从伤口侵染当年新竹及老竹。据普查,该病已广泛分布浙江竹区,计已有1市9县24处竹林发生,寄生竹种达16种以上。它对竹林生长和出笋已带来较大的损失,已成为我省竹子上的常见病、多发病、慢性病、顽固病。笋用竹基地及产笋专业户必须对防治加以高度的重视。     

竹秆锈病防治试验初报

本试验从1980年开始,经过竹秆锈病(Stereos tratum Corticioides)发生规律观察表明,此病专危害竹类。在竹杆上产生冬孢子、夏孢子和菌丝进行侵染循环。其侵染规律是:10月至翌年3月,为冬孢子堆时期;4月,冬孢子堆于雨后吸水膨胀,逐步脱落,在脱落的竹表皮上产生夏孢子;5月至7月,是夏孢子产生和侵染期;8月,夏孢子脱落后,病斑在竹表皮下繁衍大量堆状菌丝;9月中旬,菌丝上产生冬孢子堆,10月突破竹表皮外露。经接种试验,冬孢子无侵染能力,夏孢子是传播的唯一来源,夏孢予的产生又必须经冬孢子阶段。     

10种杀菌剂对花椒枝枯病室内毒力测定及田间防治试验

采用孢子玻片萌发法做了１０种杀菌药剂对花椒枝枯病的室内毒力测定,初选出７种对花椒枝枯病分生孢子较敏感的药剂参加田间防治试验。结果表明：代森铵、退菌特、代森锰锌喷雾防治效果显著,以４５％ 代森铵１００倍液防治效果为好、平均防效可达９２５％ ;多菌灵采用高压注射、根埋防治也可取得８１８％ 以上的良好防效。     

Field ready: Development of a rapid LAMP-based colorimetric assay for the causal agent of white pine blister rust,Cronartium ribicola

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.     

Cronartium flaccidum sporulates on new Euphrasia species in natural habitats in Finland

Natural sporulation of a pine stem rust, Cronartium flaccidum, was investigated in forested habitats in northern Finland. First, a diffuse sample (100) of seven species of hemiparasitic plants was collected in their natural habitats close to one another. C. flaccidum was found to sporulate on six species. The rust was most common on Melampyrum sylvaticum with 21% of the plants and 2% of the leaves carrying telia. Telia occurred occasionally also on Euphrasia frigida, E. nemorosa, E. stricta, Pedicularis palustris ssp. palustris and Melampyrum pratense (less than 5% of the plants and 0.3% of the leaves). The rust was absent on Rhinanthus minor. Second, a diffuse sample of each of M. sylvaticum, M. pratense, Euphrasia sp. and Rhinanthus sp. was collected from 10 sample plots surrounding the city area. C. flaccidum occurred on 0.29% of the leaves of M. sylvaticum, and 0.02%–0.03% of M. pratense and Euphrasia, but it was lacking from Rhinanthus. The results indicated that C. flaccidum was most common and widespread on M. sylvaticum, but sporulated sporadically also on Euphrasia sp., P. palustris and M. pratense. This is the first report of sporulation of C. flaccidum on Euphrasia frigida and E. nemorosa in their natural habitats. In contrast, a second rust observed in this survey, Coleosporium sp. needle rust, was much more common than C. flaccidum on the investigated plants. In the first site, 43%–54% of plants and 8%–17% of leaves of Melampyrum spp. and 0%–13% of plants and 0%–2% of leaves of Euphrasia spp., Rhinanthus minor and Pedicularis palustris carried uredinia or telia. In the second site, 9%–15% of leaves of Melampyrum spp. and 1%–2% of Euphrasia sp. and Rhinanthus sp. carried rust uredinia and/or telia. The results indicate frequent spore dispersal of both Cronartium and Coleosporium in the area, and versatile rust sporulation on hemiparasitic plant species.     

Cronartium flaccidum fruitbody production on Melampyrum spp. and some important alternate hosts to pine

Four Vincetoxicum species, Paeonia anomala and Melampyrum sylvaticum known to act as alternate hosts for Cronartium flaccidum, and a potential host Melampyrum pratense were inoculated either in vitro or in vivo with various aeciospore sources of C. flaccidum. All fresh C. flaccidum aeciospore sources variably produced uredia or telia on Vincetoxicum hirundinaria, Vincetoxicum mongolicum, Vincetoxicum fuscatum, Vincetoxicum nigrum, P. anomala, nine geographic provenances of M. sylvaticum, and two provenances of M. pratense. This is the first time that C. flaccidum telia were artificially produced on M. sylvaticum and the first time that M. pratense was shown to act as alternate host for C. flaccidum. The results suggest that M. sylvaticum is relatively susceptible to C. flaccidum, whereas M. pratense is almost resistant to this rust. The low host-specificity of the Finnish population of C. flaccidum was demonstrated, as V. hirundinaria from Italy was susceptible to the rust.     

Relative Susceptibility of Four Melampyrum Species to Cronartium flaccidum

The relative susceptibility of Melampyrum arvense, M. pratense, M. sylvaticum and M. nemorosum to Cronartium flaccidum was investigated by artificial inoculations. Uredinia and telia were artificially produced on plants from sown seed or transplanted from the wild in the greenhouse. This is the first report in which C. flaccidum telia were artificially produced on leaves of whole plants of M. arvense and M. pratense, the first report of successful artificial disease establishment on M. arvense and the first report of telia production on the upper surface of Melampyrum leaves. As an earlier unreported observation, telia were occasionally formed on both upper and lower leaf surfaces of M. arvense, M. sylvaticum and M. pratense. Host species, spore source and their interaction each affected some aspects of disease development. Melampyrum arvense and M. sylvaticum were the most susceptible hosts, while M. nemorosum was least susceptible. Melampyrum arvense should be considered a potentially important alternate host of C. flaccidum with its limited area of distribution.     

Susceptibility of Pedicularis spp. to Cronartium ribicola and C. flaccidum in Finland

Aeciospores of Cronartium ribicola and C. flaccidum were collected from several locations in Finland and used to inoculate Pedicularis spp. and some known and suspected alternate hosts in 2008–2009. In all trials, C. ribicola formed uredinia and telia on leaves of Ribes nigrum. No uredinia or telia of C. ribicola formed on older leaves of Pedicularis spp. but both uredinia and telia were found on young leaves of P. palustris ssp. palustris. Cronartium flaccidum produced uredinia and/or telia on leaves of P. palustris ssp. palustris, P. lapponica, Vincetoxicum hirundinaria and Melampyrum sylvaticum. Neither rust infected P. sceptrum‐carolinum, Vaccinium myrtillus, Calluna vulgaris or Ledum palustre. Similar to rusts in Asia and North America, the results showed that European C. ribicola exhibit more variable host reactions and wider alternate host ranges than earlier described. Pedicularis palustris may play a role in the spread of Cronartium in natural forests.     

Pathogenicity of Thekopsora areolata from seed orchards in Finland on Prunus spp. and Picea abies

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.     

TAXONMIC SIGNIFICANCE OF SYMPTOM CHARACTERISTICS AND AECIOSPORES SURFACE STRUTURE OF PINE NEEDLE RUST

INTRoDUrnoNRneneedlerustdiseasecausedbyCo-leosPoriumsPP.seriouslyharmspinetreesthatarelessthanloyearsold.Sincel847,LeviellsetuPCoIeosPoriumgenus,sofarintheworld,morethan9Ospeieshavebeendescribed.AInOngthem,8speCiesareautoec1ous,1speciesarendcI-OCyclic,and3speciesaredenti-cyclic,theremainingareheteroeciousI7'l6l.fuStorically,theclassificahonofColeosPo-riumisnotveryclear.lntfadihonalclassifica-hon,genusofCoIeosPorilunwasdecidedbythemorpholOgyofteliosPOres,andspecieswasdecidedbyaltem…     

Climatic favourability zones for Eucalyptus rust in Brazil

Brazilian forest‐based industries are supported by more than 5.5 million hectares of Eucalyptus growing under different climatic conditions with different degrees of favourability for rust Puccinia psidii, including both traditional and expanding areas, where such disease is of major concern for the industry, foresters and scientists. The main objective of this study was to define favourable climatic zones for Eucalyptus rust in Brazil with the following aims: (i) to develop a spatial method for estimating the mean night‐time temperature (T_ng); (ii) to assess and validate a Eucalyptus rust model; and (iii) to map Eucalyptus rust favourability zones in Brazil based on the proposed model. A straightforward method, based only on latitude, day of the year, maximum and minimum air temperatures, was developed to estimate T_ng, which is a key variable for a proper application of Ruiz rust model. Based on 37 field experiments with natural rust occurrence, it was observed that climatic conditions are determining factors for disease severity. Significant correlations between disease severity observed in the field and climatic conditions were found: a negative correlation with temperature (r = .50, p < .01) and a positive correlation with relative humidity (r = .89, p < .0001). A significant correlation (r = .81, p < .0001) between the normalized infection index, produced from Ruiz model, and the average rust score was also observed. Once the model was validated under field conditions, it was applied using historical average data of air temperature and leaf wetness duration to obtain monthly Eucalyptus rust favourability maps for the whole country. These final maps show that favourable climatic zones for Eucalyptus rust are extremely dynamic, with high temporal and spatial variability in Brazil and that climatic conditions should be considered for expansion of Eucalyptus to new areas, in breeding programmes, and for defining the most suitable seasons for forest establishment in each climate of the country. These results provide forestry managers with practical tools to reduce uncertainty about the expected severity of Eucalyptus rust in Brazil.     

Cronartium flaccidum produces uredinia and telia on Melampyrum nemorosum and on Finnish Vincetoxicum hirundinaria

Uredinia and telia were produced on Melampyrum nemorosum through inoculations with Cronartium flaccidum aeciospores collected from northern Finland, proving that M. nemorosum serves as the telial host of C. flaccidum. Melampyrum nemorosum plants were either grown from seeds collected from several geographical provenances or transplanted from natural forest stands. They were inoculated with several geographical aeciospore sources of C. flaccidum in a greenhouse. Vincetoxicum hirundinaria, M. pratense and M. sylvaticum were used as positive controls. Detached leaves of Melampyrum spp. and V. hirundinaria were also inoculated but uredinia and telia formed only on V. hirundinaria. Most of the aeciospore sources from northern Finland produced abundant uredinia and telia both on M. nemorosum from two geographical locations and on V. hirundinaria in the greenhouse. Statistically significant differences were observed in the dimensions of artificially produced telia, teliospores and urediniospores among the tested alternate hosts and spore sources. The results suggest that M. nemorosum is susceptible to C. flaccidum and therefore may play a role in southern Fennoscandia as an alternate host but it has potentially a greater role in central and eastern Europe, where M. nemorosum occurs commonly.