Ceratocystis manginecans associated with a serious wilt disease of two native legume trees in Oman and Pakistan

Abstract

A serious wilt disease has recently been found on Prosopis cineraria (Ghaf) in Oman and on Dalbergia sissoo (Shisham) in Pakistan. Disease symptoms on both these native, leguminous hosts include vascular discolouration and partial or complete wilt of affected trees. A species of Ceratocystis was consistently isolated from symptomatic material. Morphological comparisons and analyses of DNA sequence data of the ITS, β-tubulin, and EF 1-α gene regions showed that the Ceratocystis isolates obtained from both tree species represent C. manginecans. This is the same pathogen that is causing the devastating mango sudden decline disease in Oman and Pakistan. This is also the same pathogen that has been reported causing a wilting disease on Acacia mangium in Indonesia. Cross inoculation with C. manginecans isolates from P. cineraria, D. sissoo and mango showed that the fungus can cause disease on all three trees.

A possible centre of diversity in South East Asia for the tree pathogen, Ceratocystis manginecans

“…Ceratocystis manginecans is a fungal pathogen, first described from Oman and Pakistan, as the causal agent of severe mango wilt disease (Al Adawi et al, 2013b;Al Adawi et al, 2006;Van Wyk et al, 2007). The species resides in Ceratocystis sensu stricto (De Beer et al, 2014) that includes numerous cryptic species, the majority of which are aggressive tree pathogens (Al Adawi et al, 2013b;Engelbrecht and Harrington, 2005;Ocasio-Morales et al, 2007;Roux and Wingfield, 2013;Wingfield et al, 2013).…”

“…The species resides in Ceratocystis sensu stricto (De Beer et al, 2014) that includes numerous cryptic species, the majority of which are aggressive tree pathogens (Al Adawi et al, 2013b;Engelbrecht and Harrington, 2005;Ocasio-Morales et al, 2007;Roux and Wingfield, 2013;Wingfield et al, 2013). C. manginecans has also been reported as a serious pathogen of Acacia mangium trees in Indonesia, identified at the time as the new species C. acaciivora (Tarigan et al, 2011).…”

“…Concern regarding the pathogen has increased in recent years, as it has been found on the native legume trees Prosopis cineraria (Ghaf) in Oman and Dalbergia sissoo (Shisham) in Pakistan (Al Adawi et al, 2013b). This species has also been reported on the widely planted A. mangium in South East Asian countries, including Indonesia (Tarigan et al, 2011) and Malaysia (Brawner et al, 2015), and on Eucalyptus species in South China (Chen et al, 2013).…”

“…Disease symptoms associated with C. manginecans infection on M. indica and legume trees include staining of vascular tissue, stem cankers and wilt (Al Adawi et al, 2013b;Tarigan et al, 2011;Van Wyk et al, 2007). These symptoms can result in tree death within six months of infection (Al Adawi et al, 2006;Tarigan et al, 2011).…”

“…This introduction could have come from South East Asia where the fungus occurs on A. mangium (Tarigan et al, 2011), or from South-America, as suggested by Harrington et al (2014). The rapid distribution of the pathogen in Oman and Pakistan was most likely facilitated by H. mangiferae (Al Adawi et al, 2013a;Al Adawi et al, 2013b;Masood et al, 2010). This insect is thought to be native to southern Asia but has not yet been connected to outbreaks of C. manginecans in this region (Atkinson and Peck, 1994;Masood et al, 2010;Masood et al, 2008).…”