Rot root collar caused by Kretszchmaria zonata on Tectona grandis. A – B: Undersized leaves displaying yellowish to pale brown color and wilt, E – F: Rotted root, mainly at the collar region with large basal lesions, sloughing and deterioration of the bark with fruiting bodies of K. zonata flattened and encrusted on the bark. [Images from Fig S1, Alfenas et al. 2020 (with permission from authors)]

Inference phylogenetic analyses conducted in MEGA7 of internal transcribed spacer (ITS) region of rDNA and morphology features of isolates GFP131 and GFP132 of Kretszchmaria zonata. A: Phylogenetic tree generated by using Maximum Likelihood method based on the Kimura 2-parameter model, showing a well-defined clade grouped with K. zonata distinct for other Kretzschmaria species. B: Colony morphology on MEA and morphological features of sexual and asexual stage of isolate GFP132 belonging to K. zonata. [Image from Fig S2, Alfenas et al. 2020 (with permission from authors)]

In the “1KFG: Deep Sequencing of Ecologically-relevant Dikarya” project (CSP1974), we are sequencing keystone lineages of plant-interacting fungi and saprophytic fungi that are of special ecological importance for understanding terrestrial ecosystems. In addition, comparative genome analysis with saprotrophic, mycorrhizal and pathogenic fungi will provide new insights into the specific and conserved adaptations associated with each fungal lifestyle.

Kretzschmaria zonata GFP132 was isolated from infected trees of Tectona grandis in Brazil by Alfenas et al. (2020). Microscopic examination showed morphological characteristics similar to descriptions by Rogers and Ju (1998) for the genus Kretzschmaria. Phylogenetic imference by the maximum likehood method confirmed that the isolates belong to Kretzschmaria zonata (Lév.) P.M.D. Martin.

The phytopathogenic fungus causes a soft rooting of the wood. The disease begins in the root and spreads to the tree consuming the cellulose fraction, however, the lignin lamella remains intact. Therefore, the wood appears compact, but as the rotting advances its resistance decreases. The rot caused by K. zonata on trees may be lethal. The pathogen was previously reported on teak trees in Nigeria by West (1938), in Mexico by Cibrian Tovar et al. (2014) and in Brazil by Alfenas et al. (2020).

Researchers who wish to publish analyses using data from unpublished CSP genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the CSP master paper(s).