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ARS Home » Plains Area » Las Cruces, New Mexico » Cotton Ginning Research » Research » Publications at this Location » Publication #396917
Research Project: Improving the Production and Processing of Western and Long-Staple Cotton and Companion Crops to Enhance Quality, Value, and Sustainability

Location: Cotton Ginning Research

Title: A rapid and reliable method for evaluating cotton resistance to Fusarium wilt race 4 based on taproot rot at the seed germination stage

Author
item ZHU, YI - New Mexico State University
item WILLEY, KATHLEEN - New Mexico State University
item WHEELER, TERRY - Texas A&M University
item DEVER, JANE - Texas A&M University
item Whitelock, Derek
item WEDERGAERTNER, TOM - Cotton, Inc
item HAKE, KATER - Cotton, Inc
item BISSONNETTE, KAITLYN - Cotton, Inc
item ZHANG, JINFA - New Mexico State University

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2023
Publication Date: 6/22/2023
Citation: Zhu, Y., Willey, K., Wheeler, T., Dever, J., Whitelock, D.P., Wedergaertner, T., Hake, K., Bissonnette, K., Zhang, J. 2023. A rapid and reliable method for evaluating cotton resistance to Fusarium wilt race 4 based on taproot rot at the seed germination stage. Phytopathology. 113(5):904-916. https://doi.org/10.1094/PHYTO-08-22-0286-FI.
DOI: https://doi.org/10.1094/PHYTO-08-22-0286-FI

Interpretive Summary: Fusarium wilt caused by the pathogen FOV4 is a soil-borne and infrequently seed-borne fungal pathogen and has become an emerging threat to cotton production in the U.S. Tests were conducted in growth chambers and greenhouses to develop a fast, reliable and efficient method to evaluate cotton for FOV4 resistance based on root rot that leads to seedling wilt and death. The results suggested that the response to FOV4 infections at the seed germination stage is overall congruent with that at the seedling stage. This study also demonstrates that taproot dipping at the seed germination stage is a fast, reliable, and effective method for screening of cotton germplasms for FOV4 resistance. These results will help speed up and direct future studies to develop cultivars that are resistant to FOV4 disease in U.S. cotton.

Technical Abstract: Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) is a soilborne fungal pathogen threatening U.S. cotton production. The objective of this study was to develop a reliable and efficient method to evaluate cotton for FOV4 resistance based on taproot rot during seed germination through five growth chamber tests and two greenhouse tests. Seeds from eight cotton cultivars (Set 1) were germinated in a paper towel for 6 days, and taproots were inoculated with a FOV4 conidial suspension using three inoculation methods (i.e., taproot dipping, taproot wounding, and paper towel drenching), in addition to seed soaking before germination. The taproot rot-based disease incidence (DI) and disease severity rating (DSR), seed germination percentage (SGP), and plant fresh weight (PFW) were measured 7 days after inoculation. Taproot dipping was the most efficient and reliable evaluation method. The SGP and PFW were not significantly correlated with the DI and DSR, making them inappropriate to use in resistance evaluation. Pima DP 359 RF and PHY 881 RF were the most resistant with the lowest root rot. The taproot dipping method was repeated in another test and confirmed in two tests using another set of eight cultivars (Set 2). The taproot rot-based DSR at germination was significantly correlated with the DSR at the seedling stage in the greenhouse in both sets and with previous results in seedling mortality in the greenhouse and field in Set 2. The results suggest that the response to FOV4 infections at the seed germination stage is overall congruent with that at the seedling stage.