Witches’ brooms and frosty pods: Two major pathogens of cacao

Abstract

The agaric Crinipellis perniciosa (Tricholomataceae) is a hemibiotrophic pathogen which causes witches' broom disease of cacao and has recently decimated the Brazilian cacao industry. In addition to the pathogenic cacao (C-) biotype, other biotypes are found in association with unrelated plant taxa, notably bignoniaceous lianas (L-biotype), solanaceous hosts (S-biotype), and the shrub Heteropterys acutifolia (H-biotype). The Cand S-biotypes are non-outcrossing and form broom symptoms on hosts, whereas the L-biotype is outcrossing and asymptomatic. Phylogenetic analysis of several regions of the rRNA locus revealed near identity between C-and S-biotype isolates from diverse locations, with the Land Hbiotypes forming separate groupings. Preliminary analysis of sequence data from Moniliophthora roreri, causal agent of frosty pod disease, indicates that this morphologically distinct pathogen may be closely related to C. perniciosa. Similarities in host infection between C. perniciosa and M. roreri have B02084; Online publication date

Phylogenetic analysis of DNA and RNA polymerases from a Moniliophthora perniciosa mitochondrial plasmid reveals probable lateral gene transfer

“…It is the most important phytopathological problem affecting cacao-producing areas in the American continent, and has decimated the Brazilian cacao industry (Griffith et al, 2003). M. perniciosa is classified in the order Agaricales, a group including few known pathogens (Aime and Phillips-Mora, 2005), and is endemic in the Amazon region.…”

An analysis of the risk of cocoa moniliasis occurrence in Brazil as the result of climate change

“…The occurrence of moniliasis has been recently reported on the border between Brazil and Peru, near Amazon (15,27). There are land and river routes in various locations of the wide range of Brazil's border with Peru, Colombia and Venezuela.…”

“…Although moniliasis has not yet been reported in Brazil, it could be a significant threat to Brazilian cocoa crops. Recent surveys have reported the disease at the Brazil-Peru border, near the Amazon (15,27). In addition, Brazil borders other countries in which this pathogen has already been reported, such as Venezuela and Colombia (15,24).…”

“…Recent surveys have reported the disease at the Brazil-Peru border, near the Amazon (15,27). In addition, Brazil borders other countries in which this pathogen has already been reported, such as Venezuela and Colombia (15,24). Therefore, the transit of people and illegal transportation plant material (seedlings and cocoa fruit) on the border of Brazil with these countries means risks to Brazilian cocoa crops.…”

Genetic diversity of polysporic isolates of Moniliophthora perniciosa (Tricholomataceae)

“…The intraspecific classification of M. perniciosa has been based on pathogenicity data (Hedger et al, 1987;Wheeler and Mepsted, 1988) identifying 4 groups: 1) Malvaceae (biotype C), which infects mainly Theobroma and Herrania spp, causing economic damage (Evans, 1978); 2) Solanaceae group (biotype S), which infects host species from Solanum spp (Bastos and Evans, 1985;Purdy and Schmidt, 1996); 3) biotype H, which has recently been identified and infects Heteropterys acutifolia (Malpighiaceae) (Resende et al, 2000;Griffith et al, 2003), and 4) biotype L, which is saprophytic (Lianas) and colonizes a vast number of substrates, alive or dead, especially the species Arrabidaea verrucosa (Standl.) A.H. Gentry (Bignoniaceae) (Evans, 1978;Hedger et al, 1987;Griffith and Hedger, 1994a,b;Arruda et al, 2003).…”