Rigidoporus microporus and the white root rot disease of rubber

Abstract

The rubber tree, Hevea brasiliensis (Willd. ex A. Juss.) Mull. Arg., is one of the most economically important industrial crops, producing the milky latex which is the source of the valuable global commodity natural rubber. Natural rubber provides a source of income for rural communities, especially in Southeast Asia (Singh et al., 2021;Vongkhamheng et al., 2016). Due to the high demand globally for rubber, the area of rubber plantations worldwide increased gradually from 3 million ha in 1961 to 12 million ha in 2019 (FAO 2022).Approximately 90% of global rubber production is dominated by smallholders and planted in monoculture (IRSG, International Rubber Study Group, 2019). A rubber small-holding is defined as contiguous or non-contiguous areas aggregating less than 40.47 hectares (100 acres) planted with the crop (Saufe & Man, 2017). 2021) reported that 96% of rubber production yields are explained by independent variables comprising labour, plantation area, weeding and other cultivation activities by the smallholders. Ramli et al. (In addition, the income of the smallholder farmers also determines rubber production at the local scale, where low profitability leads to reduced tapping activities and even abandonment of farms (Ali et al., 2021). The conversion of primary and secondary forests to rubber monoculture decreases species richness and impacts overall species composition (Gitz et al., 2020). The introduction of this monoculture to new ecosystems has also led to the spread of nonnative pathogens and diseases (Monkai et al., 2017). Arguably, the most economically important rubber disease is white root rot (WRR) disease.

A new pathogenic polypore on urban trees: The first record of Rigidoporus ulmarius (Rigidoporaceae, Hymenochaetales) in Hungary

“…(Wang et al, 2023b). The type species of the genus Rigidoporus is Rigidoporus microporus (Sw.) Overeem, a widely distributed plant pathogenic species in the tropics, which can have significant economic importance in rubber, cocoa, or tea plantations (Oghenekaro et al, 2020;Saidi et al, 2023;Yuan et al, 2023). Rigidoporus ulmarius (Sowerby) Imazeki, is also a plant pathogenic polypore species has a cosmopolitan distribution (e.g., Rajchenberg and Robledo, 2013;Ryvarden and Melo, 2014;Ryvarden et al, 2022;Wang et al, 2023a).…”

Volatile-based diagnosis for pathogenic wood rot fungi affecting Singapore urban trees

“…Further studies confirmed that R. microporus could cause white rot disease and primarily affected the root systems of a wide range of tree species from hardwoods, conifers to food and cash crops [10,21]. It can cause significant damage and decay in the roots, leading to the weakening and eventual death of the host tree, hence regarded economically important to African and several South East Asian countries such as Malaysia, Thailand and Philippines [21,24,25].…”

“…Rigidoporus genus belongs to the order Hymenochaetales and family of Meripilaceae, contains over 40 known species [21], and commonly grow on angiosperm and gymnosperm wood [17]. Rigidoporus is phylogenetically related to Oxyporus, with the former characterised by having basidiocarps with a coloured pore surface, thick-walled encrusted hyphoid cystidia (specialised structures), and mammillate cystidioles, while the Oxyporus species are associated with light-coloured basidiocarps and thick-walled encrusted hymenial cystidia [22].…”