''Pyrrhoderma noxium'' is a species of
plant pathogen
Plant diseases are diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like orga ...
. It attacks a wide range of tropical plants, and is the cause of
brown root rot disease. It has been described as "an aggressive and destructive pathogen".
[Ribera, J., Tang, A., Schubert, M., Lam, R., Chu, L., Leung, M., Kwan, H., Bas, M., & Schwarze, F. (2016). IN-VITRO EVALUATION OF ANTAGONISTIC TRICHODERMA STRAINS FOR ERADICATING PHELLINUS NOXIUS IN COLONISED WOOD. ''Journal of Tropical Forest Science'', ''28''(4), 457–468. ] The pathogen invades roots with contact between roots of a potential host with the substrate on which the fungus is growing.
Infection
''P. noxium'' attacks the roots and lower trunk of trees, causing roots to rot and resulting in dieback (another term for root rot). It causes brown root rot disease, which afflicts over 200 plant species in tropical and subtropical regions. The pathogen can survive in the soil and on dead plant material for more than a decade, and the primary source of infection to other plants and trees is from contact with infected root material to the healthy plant's root.
Treatment
Fungicides Calixin, Bayleton, and Nustar inhibits growth for ''P. noxium'' on agar medium, however was not ultimately found to be effective in eradicating the fungus in infested wood. A mixture of
ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
and
urea
Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two Amine, amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest am ...
, as well as just volatile ammonia in itself, was found able to kill ''P. noxium'' in infested wood. Strains of
Trichoderma
''Trichoderma'' is a genus of fungi in the family Hypocreaceae that is present in all soils, where they are the most prevalent culturable fungi. Many species in this genus can be characterized as opportunistic avirulent plant symbionts. This re ...
applied in mulch around infected ''P. noxium'' trees started to grow new roots within 6–8 weeks of application, and the mycelium of ''P. noxium '' was eradicated after 8–11 weeks of exposure.
Distribution
''P. noxium'' has been recorded from tropical regions, as well as Japan and Australia, but has not been reported from South America.
List of countries where ''P. noxium'' is present
Hosts
Brown root rot
''P. noxium'' causes
brown root rot, which is a serious problem in Taiwan and
Hong Kong
Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...
.
[Lin, C., Chung, C., Wu, M., & Cho, C. (2013). DETECTION OF PHELLINUS NOXIUS DECAY IN STERCULIA FOETIDA TREE. ''Journal of Tropical Forest Science'', ''25''(4), 487–496. ]
See also
*
Root rot
Root rot is a condition in which anoxic conditions in the soil or potting media around the roots of a plant cause them to rot. This occurs due to excessive standing water around the roots.-Hydroponics Root Rot: What is It, How To Treat It, How ...
References
{{Authority control
Fungal plant pathogens and diseases
Fungi described in 1932
Fungus species