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Home • Pseudocercospora ulei ERN8 v1.0
Conidial stage of Pseudocercospora ulei.
Conidial stage of Pseudocercospora ulei.
Image Credit: Braz Tavares da Hora Júnior.
Lesions with Ascostromata.
Lesions with Ascostromata.
Image Credit: Braz Tavares da Hora Júnior.

Pseudocercospora ulei1, formerly known as Microcyclus ulei (Dothideomycetes, Ascomycota), is the most threatening plant pathogen to the world supply of natural rubber, a plant-based commodity that for several purposes has no substitutes. P. ulei causes South American Leaf Blight (SALB), a severe defoliating disease of rubber tree plantations in the humid tropical areas of South America2. Fortunately, SALB is not present in Southeast Asia countries, the major exporters of natural rubber (NR). It is estimated that NR is present in 40,000 different products, but it is particularly important for the transportation, electrical and medical industries. The world supply of NR is completely dependent on the non-occurrence of SALB is Southeast Asia, but the climatic conditions of this region are highly favorable to the disease. Planting resistant clones is the main control measure to prevent SALB induced latex losses. These clones are crucial to allow the cultivation of rubber in the humid tropical areas of South America and also strategic for preventing the collapse of NR production in case SALB is introduced into Southeast Asia.

Breeding programs aimed at developing resistant rubber clones are established, but they have been developed without proper knowledge of the genetic determinants of pathogenicity in P. ulei. To date there is only very limited information on the genetics of P. ulei. This is a slow-growing fungus that is difficult to manipulate in the laboratory. Therefore, important issues related to pathogen variability and evolution remain largely unknown. Sequencing the genome of P. ulei will allow us to move faster and more efficiently in the breeding program of rubber to produce high-yield clones with durable resistance to SALB.

 

References:

  1. Hora Júnior, B. T. da et al. Erasing the past: A new identity for the Damoclean pathogen causing South American Leaf Blight of rubber. PLoS One 9, e104750 (2014).
  2. Guyot, J. & Le Guen, V. A review of a century of studies on South American Leaf Blight of the rubber tree. Plant Dis. 102, 1052–1065 (2018).