Agronomic characterization of cotton genotypes susceptible and resistant to reniform nematode in the United States Midsouth

Authors: SINGH, BHUPINDER - University Of Missouri; CHASTAIN, DARYL - Mississippi State University; REDDY, K. RAJA - Mississippi State University; SNIDER, JOHN - University Of Georgia; KRUTZ, LARRY - Mississippi State University; Stetina, Salliana - Sally; SEHGAL, AKANKSHA - Mississippi State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2021
Publication Date: 8/28/2021
Citation: Singh, B., Chastain, D.R., Reddy, K., Snider, J.L., Krutz, L.J., Stetina, S.R., Sehgal, A. 2021. Agronomic characterization of cotton genotypes susceptible and resistant to reniform nematode in the United States Midsouth. Agronomy Journal. 113(5):4280-4291. https://doi.org/10.1002/agj2.20755.
DOI: https://doi.org/10.1002/agj2.20755

Interpretive Summary: Cotton lines resistant to reniform nematode, a microscopic worm that feeds on plant roots, have been recently developed to reduce yield losses from reniform nematode, yet little is known of their agronomic and physiological responses under field conditions. This research was conducted to determine if reniform nematode populations, cotton development, and cotton productivity vary among reniform nematode resistant (08SS110-NE06.OP and 08SS100) and susceptible (Deltapine 16 and PHY 490 W3FE) cotton lines in a field infested with the nematode. In both years of the study, reniform nematode populations in plots with resistant lines were significantly smaller than in plots with susceptible lines at harvest. However, no differences were observed for maximum plant growth rates among any of the lines tested. Resistant line 08SS110-NE06.OP had the highest late season vigor. Despite growing under higher reniform nematode pressure, the susceptible line PHY 490 W3FE showed comparable yields to 08SS110-NE06.OP. The study was unable to definitively quantify the relative contribution of resistance, innate vigor, and varietal response to management practices with respect to final crop yield. Nonetheless, this study is the first detailed report describing the development of these resistant cotton lines under reniform nematode pressure and provides a foundation for other researchers to use in future investigations.

Technical Abstract: Cotton genotypes resistant to reniform nematode (RN) have been recently developed to reduce yield losses from RN, yet little is known of their agronomic responses under field conditions. This research was conducted to determine if RN population, cotton growth and development, and yield vary among RN resistant (Gossypium barbadense introgressions; 08SS110-NE06.OP and 08SS100) and susceptible cotton genotypes (Deltapine 16 and PHY 490 W3FE) in environments infested with RN. The study was conducted over two years (2017 and 2018) in field-plots naturally infested with RN population. Growth analysis was conducted at 1- or 2-week intervals starting from 4 weeks after planting (WAP) to 12 WAP. Soil samples were taken from the top 40-cm soil depth before planting and after harvesting to determine reniform nematode populations. The three-parameter sigmoidal functions best described (r2 = 0.95 to 0.99) growth of cotton genotypes along the season, but no differences were observed for maximum growth rates among genotypes. Post-harvest RN populations significantly increased in plots grown with susceptible cotton genotypes, while RN reproduction was inhibited resulting fewer number RN in the resistant genotypes-grown soils. 08SS110-NE06.OP exhibited greater vigor than PHY 490 W3FE in the later part of season. PHY 490 W3FE showed comparable yields with 08SS110-NE06.OP despite trends were not similar for RN suppression and vigor in the later season. The information in this study could be useful to select resistant lines superior in yields and RN suppression as a parent for the development of RN resistant cultivars in cotton.