TY - JOUR
T1 - Virulence, Aggressiveness, and Fungicide Sensitivity of Phytophthora spp. Associated with Soybean in Illinois
AU - Cerritos-Garcia, Daniel G.
AU - Huang, Shun Yuan
AU - Kleczewski, Nathan Michael
AU - Mideros, Santiago X.
N1 - Funding Information:
Funding: Funding for this project provided by the North Central Soybean Research Program, the USDA National Institute of Food and Agriculture (Hatch grant number 1025315), and the Department of Crop Sciences at the University of Illinois at Urbana-Champaign.
Publisher Copyright:
© 2023 The American Phytopathological Society.
PY - 2023/6
Y1 - 2023/6
N2 - Phytophthora root and stem rot (PRR), caused by Phytophthora sojae, is one of the most devastating oomycete diseases of soybean in Illinois. Single resistant genes (Rps) are used to manage this pathogen but P. sojae has adapted to Rps, causing failure of resistance in many regions. In addition to P. sojae, recent reports indicate that P. sansomeana could also cause root rot in soybean. Soil samples and symptomatic plants were collected across 40 Illinois counties between 2016 and 2018. P. sojae (77%) was more abundant than P. sansomeana (23%) across Illinois fields. Both species were characterized by virulence, aggressiveness, and fungicide sensitivity. Virulence of all P. sojae isolates was evaluated using the hypocotyl inoculation technique in 13 soybean differentials. Aggressiveness was evaluated in the greenhouse by inoculating a susceptible cultivar and measuring root and shoot dry weight. On average, P. sojae isolates were able to cause disease on six soybean differentials. P. sojae was more aggressive than P. sansomeana. All isolates were sensitive to azoxystrobin, ethaboxam, mefenoxam, and metalaxyl. The characterization of the population of species associated with PRR will inform management decisions for this disease in Illinois.
AB - Phytophthora root and stem rot (PRR), caused by Phytophthora sojae, is one of the most devastating oomycete diseases of soybean in Illinois. Single resistant genes (Rps) are used to manage this pathogen but P. sojae has adapted to Rps, causing failure of resistance in many regions. In addition to P. sojae, recent reports indicate that P. sansomeana could also cause root rot in soybean. Soil samples and symptomatic plants were collected across 40 Illinois counties between 2016 and 2018. P. sojae (77%) was more abundant than P. sansomeana (23%) across Illinois fields. Both species were characterized by virulence, aggressiveness, and fungicide sensitivity. Virulence of all P. sojae isolates was evaluated using the hypocotyl inoculation technique in 13 soybean differentials. Aggressiveness was evaluated in the greenhouse by inoculating a susceptible cultivar and measuring root and shoot dry weight. On average, P. sojae isolates were able to cause disease on six soybean differentials. P. sojae was more aggressive than P. sansomeana. All isolates were sensitive to azoxystrobin, ethaboxam, mefenoxam, and metalaxyl. The characterization of the population of species associated with PRR will inform management decisions for this disease in Illinois.
KW - aggressiveness
KW - oomycete
KW - pathotype
KW - Phytophthora sansomeana
KW - Phytophthora sojae
KW - seed treatment
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U2 - 10.1094/PDIS-07-22-1551-RE
DO - 10.1094/PDIS-07-22-1551-RE
M3 - Article
C2 - 36415892
AN - SCOPUS:85159741263
SN - 0191-2917
VL - 107
SP - 1785
EP - 1793
JO - Plant disease
JF - Plant disease
IS - 6
ER -