Coffee Leaf Rust (Hemileia vastatrix) from the Recent Invasion into Hawaii Shares a Genotypic Relationship with Latin American Populations

Abstract

Hawaii has long been one of the last coffee-producing regions of the world free of coffee leaf rust (CLR) disease, which is caused by the biotrophic fungus Hemileia vastatrix. However, CLR was detected in coffee farms and feral coffee on the island of Maui in February 2020 and subsequently on other islands of the Hawaiian archipelago. The source of the outbreak in Hawaii is not known, and CLR could have entered Hawaii from more than 50 coffee-producing nations that harbor the pathogen. To determine the source(s) of the Hawaii inoculum, we analyzed a set of eleven simple sequence repeat markers (SSRs) generated from Hawaii isolates within a dataset of 434 CLR isolates collected from 17 countries spanning both old and new world populations, and then conducted a minimum spanning network (MSN) analysis to trace the most likely pathway that H. vastatrix could have taken to Hawaii. Forty-two multilocus genotypes (MLGs) of H. vastatrix were found in the global dataset, with all isolates from Hawaii assignable to MLG 10 or derived from it. MLG 10 is widespread in Central America and Jamaica, making this region the most probable source of inoculum for the outbreak in Hawaii. An examination of global weather patterns during the months preceding the introduction of CLR makes it unlikely that the pathogen was windborne to the islands. Likely scenarios for the introduction of CLR to Hawaii are the accidental introduction of spores or infected plant material by travelers or seasonal workers, or improperly fumigated coffee shipments originating from Central America or the Caribbean islands.

Achievements and Challenges in Controlling Coffee Leaf Rust (Hemileia vastatrix) in Hawaii

“…Passive and active samplers were installed across Hawaii Island to capture CLR spores and determine months with high dispersal, which is important to link with coffee plant phenology, weather conditions and management of CLR. The race of CLR was identified as race XXIV, which previously was reported in Brazil and Central America and it is considered highly aggressive [27,28,54]. This information is relevant to select potential coffee plants that are resistant to H. vastatrix race XXIV.…”

Impact of climate on a host–hyperparasite interaction on Arabica coffee in its native range

“…Breeding for coffee leaf rust resistance is considered a major solution for the control of the coffee leaf rust (McCook & Vandermeer, 2015; Silva et al., 2018). However, resistance against coffee leaf rust is known to frequently break down as a result of pathogen evolution, which can have huge impacts on coffee production and the livelihoods of millions of smallholder farmers (Ramírez‐Camejo et al., 2022). H. vastatrix is attacked by a fungal hyperparasite, Lecanicillium lecanii (Zimm.)…”

Intensity of Leaf Rust Disease on Four Robusta Coffee Clones in Natar, South Lampung

“…, is an important disease of coffee plants in the world that infests Arabica and Robusta coffee. This disease has been found in Indonesia since 1876, which destroyed most of the coffee plantations [6,7,8]. Coffe leaf rust can cause problems in all coffee-producing regions and can reduce production by 20-70%.…”