Determining the Diversity among Florida Isolates of Sclerotium Rolfsii the White Mold Pathogen

Phenotypic traits, such as morphological characteristics and MCGs, have been used to assess the diversity of S. ro/fsii in different areas throughout the world (Xie and Vallad 2014; Remesal et al. 2012; Cilliers et al. 2000). The information gained from these studies has provided researchers with background information about possible biological variation in S. ro/fsii population and assisted in integrated disease management by providing some insights about virulence of isolates in optimal field condition. For example, understanding the pathogens sclerotia germination and mycelia development rates in vitro can help predict infection rates in a field under optimal environments. In this study, morphological traits were not consistent between mycelial compatibility groupings, and varied within field sites and across counties (Table 3). However, colony growth after 2 days was uniform among all isolates (Table 3), indicating that infection rates among these isolates may be similar. Further research is needed to understand how colony growth rate is related to infection, and what other factors ( e.g. oxalic acid, sclerotia germinability) could also affect S. ro/fsii infection rates on peanuts.