First report of the brown root rot disease caused by Phellinus noxius, its distribution and newly recorded host plants in the Amami Islands, southern Japan

Abstract

To determine whether the brown root rot disease caused by Phellinus noxius is present in the Amami islands, which are situated near Okinawa, we conducted six field surveys from 1999 to 2005. The brown root rot disease was found in 22 tree species in 17 plant families at 25 different sites in all the islands surveyed. Sixteen of these species were newly recorded as host plants of P. noxius. The disease was more common in the low elevation plains and on hills less than 100 m above sea level than in mountainous areas. This is the first report of the brown root rot disease caused by P. noxius in the Amami Islands, Japan, and Ohshima Island is currently the northern-most distribution point of the disease in the northern hemisphere.

Brown root rot caused by phellinus noxius in the Ogasawara (Bonin) islands, southern Japan - current status of the disease and its host plants

“…Tissue samples from roots and stem bases with typical symptoms were returned to the laboratory for fungal isolation. The isolation of fungi was conducted according to Sahashi et al (2007). The identification of P. noxius was made based on the characteristics (e.g.…”

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

“…This fungus has a wide range of hosts including more than 200 species in 59 families [2] , and since then more new tree species have also been added to this list [3,4] . Despite favoring woody trees, P. noxius can also attack some herbaceous plants [2,5,6] .…”

“…Despite favoring woody trees, P. noxius can also attack some herbaceous plants [2,5,6] . P. noxius has been found in many tropical and subtropical countries and districts, including Singapore, Japan, Indonesia, Malaysia, Hai-T nan Island in China, Macao, Taiwan, Africa, Australia, Central America, and the Caribbean [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] . The wide geographical distribution of this pathogen and the severe damage it has caused have drawn significant concerns.…”

“…Conventional diagnosis of brown root rot caused by P. noxius involves in observing symptoms and isolating the pathogen from diseased tissues [2,4] . Trees infected with P. noxius normally present wilting and discoloring of foliage [13] .…”

Selection of species resistant to the wood rot fungus Phellinus noxius

“…This analysis is based on the spreading characteristics of P. noxius. Because the fruiting bodies of this fungus is rarely found in the field (Ann et al 1999a;Ann et al 2002), the fungus is thought to spread primarily via root-to-root contact (Hodges and Tenorio 1984;Nandris et al 1987;Ann et al 2002;Sahashi et al 2007). A tree may thus "have the chance to be infected" if its root range intersects with that of diseased trees.…”