Submitted to: Biocontrol
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2010
Publication Date: 11/20/2010
Citation: Shetty, K., Minnis, A., Rossman, A.Y., Jayachandran, K. 2010. Brazilian peppertree seed-borne pathogen, Neofusicoccum batangarum, a potential biocontrol agent. Biocontrol. 56:91-97. Interpretive Summary: Invasive weeds destroy delicate ecosystems especially in the Florida Everglades National Park. Recently Brazilian peppertree has invaded more than 4,000 acres within the Park. A fungus was discovered that kills the seeds and seedlings of this tree and thus may prove useful in controlling this weed. In this research it was determined that this fungus is effective in killing seedlings of Brazilian peppertree. In addition, the host range of this fungus on related host species was determined. This research will be used by ecologists and plant pathologists working to control this noxious weed tree.
Technical Abstract: The invasive exotic Brazilian peppertree, Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) has become a serious threat to the delicate ecosystem of Everglades National Park. More than 4,000 acres land in the Hole-in-the-Donut (HID) area within the Park has been infested with Brazilian peppertree. Brazilian pepper tree is a prolific seed producer, which enhances its invasive potential. Native phytopathogens can be a viable tool in the management of the exotic species; no studies have been reported on the occurrence of native seedborne pathogens of Brazilian pepper in Florida. Our studies showed that Brazilian peppertree drupes are affected by seedborne fungal pathogens. These fungal pathogens either cause germination failure or allow germination to occur but will attack the seedling later resulting in reduced vigor or seedling death. The seedborne fungal isolate BPSPF-1 was found to be virulent, and when inoculated it was able to kill Brazilian pepper seedlings in seedling assay, as well one year old saplings in greenhouse trials. Field inoculation of Brazilian peppertree branches with BPSPF-1 resulted in dieback symptoms. Host range study on one related native (winged sumac) and non-native species (Mango) showed that both were not affected by girdle inoculation of stem. The BPSPF-1 isolate produced dark melanized mycelia on agar media and did not produce conidia or other fruiting structures. Based on the ITS DNA sequence analyses the isolate was identified as Neofusicoccum batangarum.