Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan

Brown root rot disease is a major constraint on cashew plantation in Pekat District, West Nusa Tenggara. Its causal agent has not been characterized. This paper describes efforts to study the pathogen, distribution and loss. Field study was conducted in Pekat District in 2003. Laboratory experiments to isolate and test the causal agent were conducted in the Indonesian Spices and Medicinal Crops Research Institute, Bogor. Research results showed that the disease was found widespread in several villages in Pekat District, such as Pekat, Beringin Jaya, Sorinomo, and Nangamiro. Total number of died cashew trees was 1,075 equals to 5,106 kg kernel yield lost, worth Rp20.5 million. Infected trees showed leaf yellowing and defoliation leading to die. The lateral and taproots near collar were encrusted with gravel, earth, and brown mycelia sleeves. The fungus produced arthrospores and brown pigmentation on agar medium containing 0.05% gallic acid. An isolate of the fungus induced typical disease symptoms following inoculation on 5 month-old cashew seedlings. These results indicated that the causal agent of mass decline of cashew in Pekat District is Phellinus noxius. In field, the fungus also infects a barrier tree (Lannea coromandelica [Houtt.] Merr.) (Anacardiaceae), locally known as kedondong pagar or kayu bantenan.

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Cylindrocladium clavatum. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056400422 ◽

1974 ◽

Author(s):

A. Peerally

Keyword(s):

Geographical Distribution ◽

Camellia Sinensis ◽

Root Rot ◽

Araucaria Angustifolia ◽

Eucalyptus Saligna ◽

Bright Yellow ◽

Cylindrocladium Floridanum ◽

Old Trees ◽

Brown Root Rot ◽

Phellinus Noxius

Abstract A description is provided for Cylindrocladium clavatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Araucaria angustifolia, Camellia sinensis, Eucalyptus saligna and Pinus. DISEASE: Occasionally associated with Cylindrocladium floridanum[Calonectria kyotensis] and Cylindrocarpon tenue on rotting roots of unthrifty tea bushes in Mauritius. Associated with a root disease of dying 10-15 year old trees of Araucaria angustifolia (Hodges & May, 1972). Roots of such trees are pitch-soaked and copiously exude resin, causing large quantities of soil to stick to the roots, thus resembling in symptomatology the brown root rot caused by Phellinus noxius. Also isolated from the roots of dying trees of several species of Pinus (Hodges & May, 1972). The pine needles on affected trees turn bright yellow, droop and finally turn brick red. Roots were pitch-soaked but resin exudation was slight. Also isolated from seedlings of Eucalyptus saligna (Hodges & May, 1972). GEOGRAPHICAL DISTRIBUTION: Brazil, Mauritius. TRANSMISSION: The pathogen is soil-borne.

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Genetic differentiation and spatial structure of Geosmithia morbida, the causal agent of thousand cankers disease in black walnut (Juglans nigra)

Current Genetics ◽

10.1007/s00294-013-0414-x ◽

2013 ◽

Vol 60 (2) ◽

pp. 75-87 ◽

Cited By ~ 10

Author(s):

Denita Hadziabdic ◽

Lisa M. Vito ◽

Mark T. Windham ◽

Jay W. Pscheidt ◽

Robert N. Trigiano ◽

...

Keyword(s):

Genetic Differentiation ◽

Spatial Structure ◽

Black Walnut ◽

Causal Agent ◽

Juglans Nigra ◽

Geosmithia Morbida ◽

Thousand Cankers Disease

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Molecular diagnosis of the brown root rot disease agent Phellinus noxius on trees and in soil by rDNA ITS analysis

Applied Environmental Biotechnology ◽

10.18063/aeb.2016.01.002 ◽

2016 ◽

Vol 1 (1) ◽

pp. 81 ◽

Cited By ~ 1

Author(s):

Yong-Feng Wang ◽

Han Meng ◽

Victor W. Gu ◽

Ji-Dong Gu

Keyword(s):

Hong Kong ◽

Tree Species ◽

Root Rot ◽

Diagnostic Technique ◽

Its Region ◽

Pcr Primers ◽

Molecular Technique ◽

Wide Range ◽

Brown Root Rot ◽

Phellinus Noxius

Phellinus noxius (P. noxius) is an important pathogen that causes brown root rot of trees in tropical and sub-tropical areas and has led to severe damage to trees. A quick and accurate diagnostic technique is essential to the timely confirmation of the pathogen and possible treatment. In this study, a fast, sensitive and accurate approach of molecular technique was used to diagnose the brown root rot pathogen on trees and in soils of subtropical Hong Kong. Two pairs of specific PCR primers were used to amplify the target rDNA internal transcribed spacer (ITS) region through polymerase chain reaction (PCR) for both tree tissues and soil samples. The amplified ITS fragments were then sequenced and analyzed phylogenetically for the diagnostic identification of the pathogen P. noxius. The results showed that 13 of 38 suspected trees in Hong Kong were infected with P. noxius through molecular detection. The pathogen showed no specific preference to any particular tree species. Quantitative PCR was applied to soils grown with trees identified both positive and negative for P. noxius, but the soils with healthy trees were also found positive for P. noxius. For the first time, P. noxius was reported to infect a wide range of tree species in Hong Kong and widely presented in soils, probably serving as a reservoir for the pathogen. Through this study, it is proposed that P. noxius is a soil-borne pathogen, which increases its infectivity when trees start to grow in the soil as a means in addition to the previously proposed root-to-root contact.

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Genetic and Morphological Evidence that Phoma sclerotioides, Causal Agent of Brown Root Rot of Alfalfa, Is Composed of a Species Complex

Phytopathology ◽

10.1094/phyto-04-10-0107 ◽

2011 ◽

Vol 101 (5) ◽

pp. 594-610 ◽

Cited By ~ 9

Author(s):

Michael J. Wunsch ◽

Gary C. Bergstrom

Keyword(s):

Root Rot ◽

Genetic Relatedness ◽

Single Gene ◽

Axenic Culture ◽

Causal Agent ◽

Morphological Evidence ◽

Data Set ◽

Morphological Differences ◽

Phoma Sclerotioides ◽

Brown Root Rot

Phoma sclerotioides, causal agent of brown root rot of alfalfa, causes severe root and crown lesions on alfalfa and other perennial forage legumes in regions with harsh winters. Isolates of P. sclerotioides exhibit diverse cultural morphologies on potato dextrose agar (PDA), suggesting that they may exhibit a high degree of genetic diversity. To investigate the genetic relatedness of P. sclerotioides isolates, 154 isolates from North America were sequenced at 10 loci. Maximum parsimony and maximum likelihood analyses of the complete 10-locus data set placed isolates into multiple strongly supported clades, and analyses of gene-jackknife and single-gene partitions of the data set indicated robust support for six major clades and three subclades. Genetic differences corresponded closely to differences in conidial size and septation, pycnidial neck length, mycelial pigmentation, and growth rate in axenic culture at 18 and 25°C. Isolates exhibited morphologies broadly consistent with the species description of P. sclerotioides, and new species were not designated. On the basis of genetic and morphological differences, we propose establishing seven infraspecific varieties within P. sclerotioides: P. sclerotioides var. sclerotioides, champlainii, viridis, obscurus, steubenii, macrospora, and saskatchewanii. All varieties of P. sclerotioides caused brown root rot of alfalfa and grew well at low temperatures.

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