Photosynthesis measurements using PhotosynQ reflects soybean root health and helps predict sudden death syndrome (SDS) symptom development
M. ROTH (1), J. Wang (1), Z. Noel (1), E. Papenfuss (1), G. Austic (1), D. TerAvest (1), Y. Yang (1), J. Chen (1), D. Kramer (1), M. Chilvers (1) (1) Michigan State University, U.S.A.

Soybean sudden death syndrome (SDS) is caused by the fungal pathogen Fusarium virguliforme in the U.S. and consists of two disease phases; root rot followed by foliar chlorosis caused by fungal phytotoxins. Currently, destructive sampling is the way to detect early root rot symptoms. PhotosynQ links an open source data-sharing platform to the MultispeQ device, which non-destructively measures 7 different photosynthesis associated variables in approximately 15 seconds. The objectives of this study were to determine if photosynthesis associated variables obtained with the MulitspeQ were indicative of real-time root health and whether or not these variables could be used to predict the severity of foliar SDS symptoms. A field trial was established in a location naturally infested with F. virguliforme, and parameters including root rot, foliar SDS severity ratings, relative F. virguliforme quantities, and MultispeQ measurements were collected. Destructive sampling parameters correlated well with late season foliar SDS symptoms. The quantum yield of energy losses (PhiNO) at early growth stages had a significant negative correlation with late season foliar SDS symptoms. Interestingly, MultispeQ measurements of both PhiNO and the quantum yield of photosystem II (PhiII) at later growth stages had significant negative correlations to late season foliar SDS symptoms. This may indicate a potential overregulation of photosynthesis by F. virguliforme during SDS development.

Abstract Number: P20-715
Session Type: Poster