Pseudostem rot caused byCorticium rolfsii,a new disease ofMusa sp. in Tamil Nadu,India

In 1987 a new disease, called pseudostem rot, was observed on 3–5-month-old banana plants(Musa sp.) cv. ’Robusta’. The pathogen was isolated in pure culture and identified asCorticium rolfsii (Sacc.) Curzi, teleomorph ofSclerotium rolfsii Sacc. The teleomorphic stage of the fungus was observed inside the pseudostem sheath. The pathogen produced leaf spot diseases (by basidiospores) on 16 tested host plants from various families.     

Collar rot of Chlorophytum borivilianum caused by Corticium rolfsii: a new disease

A new disease of Chlorophytum borivilianum , characterized by symptoms of collar rot, has been observed in experimental farms of the National Botanical Research Institute, Lucknow, India. The pathogen has been isolated and identified as Corticium rolfsii.     

烟草赤星病危害烤烟产量产值损失测定

在烤烟生长中后期 ,应用40%菌核净500倍液人为控制烟草赤星病发生程度 ,形成不同危害梯度 ,以研究烟草赤星病对产量产值的影响。经试验分析 ,建立数学模型。中上等烟产量损失率(Y₁)与病情指数(X)的关系式:Y₁=0.1516+1.2824X;产值损失率(Y₂)与病情指数(X)的关系式:Y₂=0.3239+0.9831X。     

牡丹上的一种新病害——牡丹瘤点病

介绍了牡丹瘤点病的症状,病菌经PDA培养基培养,进行病原菌鉴定,引起该病发生的病原菌为瘤座孢菌(Tubercularia sp.)。     

A new yellowing disease of cucurbits caused by a luteovirus, cucurbit aphid-borne yellows virus

Since 1988, a yellowing disease of melon, cucumber and zucchini squash has been frequently observed in summer and autumn crops in France. Infected plants show yellowing and thickening of the older leaves; symptom intensity differs depending upon cultivar and season, and can be easily overlooked when plants are already infected by mosaic-inducing viruses or other pathogens. The disease is associated with the presence of a virus with spherical particles c. 25 nm in diameter, which is readily transmitted in a persistent manner by the aphids Myzus persicae and Aphis gossypii , but not mechanically. Serological analysis, nucleic-acid-hybridization experiments and host-range studies indicate that the virus is distantly related to, but distinct from, beet western yellows virus (BWYV). We propose to name this virus cucurbit aphid-borne yellows virus (CABYV), and to consider it as a tentative new member of the luteovirus group. CABYV was found to reduce significantly the yields of melon and cucumber by decreasing the number of fruit per plant but not by altering the fruit shape or quality. Preliminary investigations of the epidemiology of CABYV indicate that the virus is common in weeds and in cultivated cucurbits. CABYV was frequently detected in various regions of France, suggesting that it is one of the most prevalent viruses infecting cucurbits in this country.     

Biological control of southern blight disease of tomato caused by Sclerotium rolfsii with simplified mycelial formulations of Trichoderma koningii

Two simple formulations of an antagonistic strain of Trichoderma koningii were employed against southern blight disease caused by Sclerotium rolfsii in seedling, potted outdoor and field-grown tomatoes (cvs. Ife No. 1 and Ibadan Local). Corn cob germling inoculum and mycelium powder of T. koningii significantly controlled ( P ≤0·05) symptoms of damping off, blight and wilting in both tomato cultivars. The populations of the antagonist increased from an initial 1 × 10⁴ to about 1 × 10⁶ colony-forming units per g of soil in the protected plants. Moreover, sclerotial counts decreased significantly ( P ≤0·05) in these soils and those sclerotia found had been parasitized by T. koningii. Trichoderma -protected plants were more vigorous than those in the other treatment categories. The significance of these results is discussed in relation to the use of Trichoderma in appropriately simplified formulations.     

A new disease in tulip caused by Corynebacterium oortii nov. spec.

A new bacterial disease in tulip is described. The symptoms consist of: yellow spots on the bulb and silvery streaks and spots or roughened areas on the leaves. Some of the leaf symptoms have been observed in the field for many years, which indicates that the disease has been present for a long time but has never been disastrous. The occurrence seems to be strongly influenced by climatic conditions. Some characters of the pathogen are compared with those of other species ofCorynebacterium.Samenvatting In 1967 werd vastgesteld dat in tulp een bacterieziekte voorkomt, waarvan in 1964 de eerste duidelijke symptomen op de bol werden waargenomen. De symptomen in het blad zijn al veel langer bekend. De symptomen op de eerste witte rok van de bol kunnen tijdens de bewaring worden waargenomen nadat de bruine huid is gescheurd. Eerst ontstaan plekken die zijn samengesteld uit witte puntjes ter grootte van een speldeknop. Deze plekken worden geel, zwellen op en scheuren tenslotte vaak met kleine barstjes. Op grond van dit symptoom is de naam geelpok aan deze ziekte gegeven. In een varder stadium van het onderzoek werden bovengrondse symptomen bekend. In de kas en op het veld werden in ontwikkeling geremde planten gevonden, die over de gehele lengte van het blad één of enkele zilverkleurige smalle strepen toonden. De bollen van dergelijke planten toonden altijd de beschreven gele pokken. Op het veld werden bovendien later nog andere bovengrondse symptomen gevonden. Ten eerste zilverkleurige plekken van circa 5 mm diameter op het blad. Ten tweede een scheuren en opkrullen van de epidermis vooral aan de bladpunt. Dit laatste symptoom is al vele jaren bekend onder de naam helsvuur; het werd tot nut toe aan een fysiologische oorzaak (kou) toegeschreven. Opmerklijk is dat van aangetaste bladeren met de genoemde verkleuring reeds bij een lichte aanraking de epidermis scheurt.Uit alle beschreven symptomen werden herhaaldelijk identieke bacteriën geïsoleerd. Met deze isolaties werden na kunstmatige infectie de beschreven symptomen verkregen. Hoewel de bacterie door vele eigenschappen vrij nauw verwant is aanCorynebacterium betae zijn voldoende argumenten gegeven om hem als een aparte soort te kunnen beschouwen.     

A new leaf spot disease of Cuphea spp. caused by Chaetomella raphigera

A new leaf spot disease of Cuphea spp., an emerging oilseed crop, was observed in the experimental fields of the National Botanical Research Institute, Lucknow, India. The pathogen was isolated and identified as Chaetomella raphigera.     

Meloidogyne luci,a new root‐knot nematode parasitizing potato in Portugal

In 2013, during a field survey conducted in Portugal on potato, Solanum tuberosum, an unusual esterase (EST) phenotype was detected in a root‐knot nematode (RKN) from potato roots collected in Coimbra. This Portuguese isolate was purified and maintained on tomato, S. lycopersicum, and morphological, biochemical and molecular characteristics were studied. Perineal pattern morphology was highly variable, similar to Meloidogyne ethiopica and not useful for identification. The EST phenotype, from young egg‐laying females, displayed three bands similar to the Brazilian M. luci (L3) and distinct from M. ethiopica (E3). Phylogenetic analyses of mitochondrial cytochrome oxidase subunit I and the mitochondrial DNA region between COII and 16S rRNA genes revealed that the Portuguese isolate grouped with M. luci isolates close to M. ethiopica isolates. However, considering the ITS1‐5.8S‐ITS2 region, the Portuguese isolate grouped with isolates of M. luci, M. ethiopica and M. hispanica, which limits the confidence of this region for M. luci diagnosis, and its differentiation from other species with morphological similarities. The M. luci pathogenicity to potato was also assessed in 16 commercial cultivars and compared with M. chitwoodi, considered to be a quarantine RKN species by EPPO. All potato cultivars were susceptible to both Meloidogyne species with gall indices of 5 and higher reproduction factor values ranging from 12.5 to 122.3, which suggests that M. luci may constitute a potential threat to potato production. In the present study, M. luci is reported for the first time attacking potato in Portugal.     

A new anthracnose disease of pyrethrum caused by Colletotrichum tanaceti sp. nov

A new pathogen of pyrethrum (Tanacetum cinerariifolium) causing anthracnose was described as Colletotrichum tanaceti based on morphological characteristics and a four‐gene phylogeny consisting of rDNA‐ITS, β‐tubulin (TUB2), glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and actin (ACT) gene sequences. The fungus produced perithecia in culture, requiring an opposite mating type isolate in a heterothallic manner. The initial infection strategy on pyrethrum leaves involved the formation of appressoria followed by production of multilobed infection vesicles in the epidermal cells. Infection and colonization then proceeded through thinner secondary hyphae, which resulted in the initial production of water‐soaked lesions followed by black necrotic lesions. The infection process was suggestive of a hemibiotrophic infection strategy. Moreover, phylogenetic analysis clearly showed that C. destructivum, C. higginsianum and C. panacicola were separate species that also had similar intracellular hemibiotrophic infection strategies as C. tanaceti, which all clustered in the C. destructivum complex. Colletotrichum spp. were detected at 1% incidence in seed of 1 of 19 seed lines, indicating the potential for seed as a source of inoculum into crops. Colletotrichum tanaceti was detected in leaf lesions from 11 of 24 pyrethrum fields surveyed between April and July 2012, at a frequency of 1·3–25·0% of lesions. Anthracnose probably contributes to the complex of foliar diseases reducing green leaf area in pyrethrum fields in Australia.     

一种由可可毛色二孢引起的春芋新病害

正可可毛色二孢(Lasiodiplodia theobromae(Pat.) GriffonMaubl.)是由Griffon和Maublanc~([1])在对Botryodiplodia theobromae进行订正的基础上而确立,Alves等~([2])于2008年对这个种又进行了研究并补充了DNA序列信息。可可毛色二孢是一种重要的病原菌,可引起多种植物的枯萎、根腐及焦枯等病害症状~([3,4])。而假可可毛色二     

A new bacterial disease of jojoba (Simmondsia chinensis) caused by Burkholderia andropogonis

A leaf spot of jojoba caused by Burkholderia andropogonis is described for the first time. Symptoms ranged from necrotic flecking with comparatively large watersoaked halos to larger 'eyespot' lesions c. 3 mm in diameter with watersoaked halos 1–1·5 mm wide. The necrosis was light tan in colour. Isolates from jojoba displayed variable pathogenicity to other known hosts of B. andropogonis ( Dianthus , Cicer , Gypsophila and sorghum), but were not pathogenic, or only weakly so, to sweetcorn, Limonium and Trifolium . Identification was confirmed by cell-wall fatty acid composition and the bacterium's possession of a single polar flagellum.     

云南烟草上1种新的细菌性病害病原鉴定

 2006~2007年在云南文山州的西畴县和保山市的昌宁县发现1种由细菌侵染引起的烟草新病害。主要发生在苗期(漂浮育苗)和移栽期,症状开始为白色至暗绿色小斑点、湿腐和茎上出现褐色斑点,在KB培养基上产生荧光。根据致病性、菌体形态、培养性状、生理生化反应、Biolog测试和16S rDNA序列分析将该病原菌鉴定为铜绿假单胞菌(Pseudomonas aeruginosa)。尽管该病害曾在菲律宾发生,但在中国尚属首次报道。     

茄青枯病菌引起的新病害-罗汉果青枯病

 罗汉果为葫芦科(Cucurbitaceae)罗汉果属[Siraitia grosvenorii(Swingle) C.Jeffrey]植物。罗汉果中含有0.8%~1.0%的罗汉果甜甙,其甜度为蔗糖的300倍,是肥胖症、高血压、高血脂、糖尿病等患者最理想的甜味剂与保健品。罗汉果甜贰远销美国、日本等国外市场,产品供不应求。     

Sweet potato stem blight caused by Alternaria sp.: A new disease in Ethiopia

A new sweet potato disease was discovered in Ethiopia. The disease mainly affects the stems and petioles of sweet potato and the name sweet potato stem blight is proposed. The pathogen is a species ofAlternaria, for which no definite name has been found so far. Sweet potatoes were most susceptible, tomatoes were slightly susceptible, and muskmelons and chilli peppers were resistant. Thorn apples and onions showed slight to moderate symptoms, butAlternaria was not reisolated from these two species. Although all sweet potato varieties tested were susceptible, there were significant differences in sensitivity.     

A strawberry disease caused by Acremonium strictum

We report Acremonium strictum as the causal agent of a new disease in strawberry plants (Fragaria x ananassa Duch.) in the Northwest of Argentina. Both the structure of conidiophores and the sequence spanning the internal transcribed spacers 1 and 2 (ITS1 and ITS2) of the nuclear ribosomal DNA (rDNA) allowed confirming the affiliation of the isolate, corresponding to A. strictum. An analysis of symptoms and lesions caused by the strain of A. strictum in susceptible cultivars showed that the typical symptoms are as follows: in an early stage, small necrotic light-brown spots in leaves and petioles increase in number and size as the disease progresses; in a more advanced stage, dark necrotic areas expand over petioles and leaves causing strangulation of petioles and the plant wilt. Crown rot was not observed even at a very advanced stage of the disease.