Link to home

Cannot retrieve the URL specified in the Content Link property. For more assistance, contact your site administrator.

Spore production of Phyllosticta spp. in citrus leaf litter associated with citrus black spot in Florida
Ke Zhang: University of Florida; Jeffrey Rollins: University of Florida; Megan Dewdney: University of Florida
<div>The causal agent of citrus black spot (CBS), <i>Phyllosticta citricarpa </i>is a quarantine fungal pathogen in Europe and the US. In the spring of 2010, CBS and the pathogen were found in Florida. Based on previous research, <i>P. cit</i> is heterothallic and due to the clonality of the Floridian <i>P. cit</i> population, conidia are presumed to be the primary inoculum in Florida. <i>P. capitalensis</i> is a globally distributed endophytic and homothallic species that is widely associated with diverse plant genera including citrus.<i> </i>Ascospores and conidia of <i>P. cap</i> are common in Floridian citrus leaf litter. Understanding the dynamics of spore production of these two species can help the development of CBS inoculum management. From May 2014 to May 2017, 40 samples of 25 leaves were collected biweekly from leaf litter in a southwest Florida grove. Ascospores and conidia were collected from leaves with <i>Phyllosticta</i> spp. fructifications from each sample. Real-time PCR was performed to determine the presence and quantity of <i>P. cit</i> and <i>P. cap </i>DNA in leaf tissue, ascospores, and conidia. The results showed from 2014 to 2017, the biomass of <i>P. cit</i> in leaf litter tissue increased significantly (P < 0.01) while the biomass of <i>P. cap</i> was consistent during 2015-2016 season (P = 0.19) and 2016-2017 season (P = 0.07). <i>P. cap</i> DNA is universally present in ascospore suspensions.The increasing ratio of <i>P. cit</i> to <i>P. cap</i> DNA in conidia suspensions indicated increasing conidia production of <i>P. cit </i>in groves.</div>

View Presentation