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ABSTRACTArmillaria(honey fungus) is a virulent necrotrophic pathogen that causes Armillaria root disease. Conventional Armillariainoculation assays use young saplings as hosts and consequently are cumbersome, frequently conducted outdoors, and take many years from establishment to analysis of infection. We have developed and evaluated a faster inoculation assay for Armillariathat uses herbaceous plants as hosts, is carried out in controlled conditions, and reduces experimental durations to 3 months. Plant species of known susceptibility to Armillariaand comparisons between virulent A. melleaand opportunistic A. gallicawere used to validate the assay. Mortality and diagnostic symptoms of Armillariaroot disease such as epiphytic rhizomorphs and mycelial fans were used to assess levels of infection. We also attempted to reduce assay preparation time by substituting woody inocula with agar inocula, but typical symptoms of Armillaria root disease were only observed on plants infected with woody inocula. Through our assay, we identified five new potential herbaceous hosts of Armillaria: Kniphofia hirsuta, Hordeum vulgare, Lobelia cardinalis, Nicotiana tabacumand Helenium hoopesii– further expanding the extensive list of plants with susceptibility to Armillariaand suggesting infection of herbaceous species may be more widespread than currently acknowledged.

The article offers information on problems caused by Phytophthora, a genus of plant damaging oomycetes or water molds, in plants and also offers suggestions to protect plants against them. It reveals that most of Phytophthora species cause root decay and sparse foliage in perennials, shrubs and trees. It also mentions that gardeners should take a history of plant source and cultivation before buying the plants from nurseries in order to prevent the phytophthora infection.

A non-papillate, heterothallic Phytophthoraspecies first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1α, and β-tubsupported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauseriihas been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauseriiZ.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate.

The article offers information on the ornamental plants' diseases discovered in the gardens of Great Britain. It states that due to plant trade globalization, gardens in the country are being exposed to new varieties of plant pathogens including leaf spot and blight fungi, powdery mildews and oomycetes. It also offers suggestions on how plant traders can minimize the risks of plants diseases such as awareness on plants origin, quarantine newly purchased plants, and avoid instant impact plants.

The article focuses on the new Buxus plant disease caused by the fungus Cylindrocladium buxicola in Great Britain. The infection, which is reportedly widespread in the country according to the Royal Horticultural Society, creates leaf spots on the leaves, black streaks on the stem, severe defoliation, and dieback. The status of Cylindrocladium buxicola was identified through a series of morphological characters and DNA sequence data.

Offers techniques and advice on gardening. Steps in overwintering dahlia tubers; Ways to harvest wild mushrooms; Tips on preparing Christmas bulbs.

A leaf and twig blight disease of Buxusspp. was found to be associated with a new species of Cylindrocladium. The novel species status was confirmed using morphological characters, sequencing of the ribosomal 5.8S RNA gene and the flanking internal transcribed spacers (ITS), the β-tubulin gene, and the high mobility group (HMG) of the MAT2 mating type gene. Cylindrocladium buxicolais proposed as a new name. Fifteen isolates from the UK and one isolate from New Zealand were paired in all combinations but no fertile perithecia were obtained suggesting that C. buxicolais heterothallic and all isolates belonged to one mating type. AFLP analysis showed that the isolates collected in the UK and New Zealand are genetically homogenous. Phylogenetic analyses indicated that this species falls within a new lineage.

The article focuses on the box blight plant disease and proposed measures for the management of the disease. It recalls the introduction of the fungus Cylindrocladium buxicola in Great Britain in the 1990s which has caused leaf spots, defoliation, die-back and death among the Buxus plant species or box. It discusses the life cycle, death as well as infectivity of the fungus. One proposed action to address the problem involves the development of a diagnostic tool for non-specialists.

The article offers guidance on how gardeners in Great Britain can reduce the effects of Phytophthora ramorum and P. kernoviae, non-invasive diseases that are only recently introduced to the British Isles. It cites the detection of P. ramorum in 2002 in mostly container-grown ornamentals, the appearance of P. kernoviae in 2003 in the Southwest, and the extensive mortality of Japanes larch caused by P. ramorum in 2009. Control measures include fungicides, mulching, and monitoring of plants.

The article discusses management of the root disease honey fungus. Naturally thriving in woodlands, the fungus is known for its virulence, able to kill a full-sized tree in a matter of years. Occurrence can be common in gardens situated near woodlands, hedgerows, and orchards where infected trees or stumps are located. Rhizomorphs are considered as means of infection. Gardeners are advised to install a physical barrier or removing root or stump material of an infected plant.