Resilience of cotton cultivars to chilling stress during germination

Authors: GUPTA, SURABHI - Mississippi State University; LEKSHMY, VALSALA - Mississippi State University; REDDY, K. RAJA - Mississippi State University; Stetina, Salliana - Sally; BHEEMANAHALLI, RAJU - Mississippi State University

Submitted to: Plant Physiology Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2023
Publication Date: 10/5/2023
Citation: Gupta, S., Lekshmy, V.S., Reddy, K., Stetina, S.R., Bheemanahalli, R. 2023. Resilience of cotton cultivars to chilling stress during germination. Plant Physiology Reports. 28. https://doi.org/10.1007/s40502-023-00746-4.
DOI: https://doi.org/10.1007/s40502-023-00746-4

Interpretive Summary: Cotton is an important commercial crop that is frequently subjected to various stresses that limit its productivity and growth. Chilling stress is one such stress that can severely inhibit cotton germination and establishment. The present study investigated how chilling stress affected germination and seedling vigor in 25 cotton varieties. The result of the study showed a significant decline (19%) in germination percentage under chilling (18 °C) compared to the control temperature (28 °C). On average, the time taken for 50% germination under chilling stress was increased by 51.5 hours compared to the control. Seed size did not affect germination ability. Cotton varieties with reduced radicle length and dry weight with a low vigor index were highly vulnerable to chilling stress. Varieties with faster germination rates and higher seedling vigor displayed greater resilience to chilling. Overall, this study identified variability in chilling tolerance among varieties. Growers who wish to plant earlier than normal can select from varieties with greater chilling tolerance. Further, plants with chilling tolerance could be used as parents in cotton breeding programs to develop new varieties with chilling stress tolerance.

Technical Abstract: Cotton, an important commercial crop, is frequently subjected to various stresses that limit its productivity and growth. Chilling stress is one such stress that can severely impact cotton germination and establishment. Several factors, including stress level, duration of exposure, and cultivar type determine the effect of chilling stress on germination. The present study investigated how chilling stress affected germination and seedling vigor in 25 cotton cultivars. The result of the study showed a significant decline (19%) in germination percentage and time taken for germination under chilling (18 °C) compared to the control temperature (28 °C). On average, the time taken for 50% germination under chilling stress was increased by 51.5 hours compared to the control. There was no significant correlation between seed size and germination ability traits. Moreover, cultivars with reduced radicle length and dry weight with a low vigor index were highly vulnerable to chilling stress. Phenotypic variations in the stress tolerance index indicated that cultivars with faster germination rates (PHY400 and STNV4990) and higher seedling vigor displayed greater resilience to chilling. Overall, this study identified variability in chilling tolerance traits and cultivars, which could be exploited in breeding to select suitable cultivars for chilling stress tolerance.