Plant Traits in Spring and Winter Canola Genotypes Under Salinity

Abstract

Concerning rising salinity and declining freshwater supply in the U.S. Southern Great Plains, alternative crop production choices using marginal saline irrigation water are irresistible. The study investigated plant traits related to salt tolerance in greenhouse canola (Brassica napus L.) in 2022 and 2023. Spring and winter canola, including ten genotypes each, were evaluated at six salinity levels (0; control, 2, 4, 6, 8, and 8 dS m−1 EC). Plant height, stem mass, leaf area, and specific leaf area (SLA) showed a negative linear response, while quadratic relationships were observed in biomass and leaf mass with increased salinity levels. Substantial negative salinity impacts on plant traits occurred at ≥6 dS m−1 EC (p ≤ 0.01) except for SLA. Overall, winter canola genotypes: Athena, Ericka, CP320WRR, CP115W, and CP225WRR, and spring genotypes: Empire, Monarch, Profit, and Westar, were relatively more salt-tolerant than others. Spring canola showed greater salinity tolerance than winter canola. Salinity stress resulted in differential responses of greater leaf mass in winter canola but more efficient leaf area production in spring canola. SLA and stem mass were highly correlated with most parameters. Findings indicate SLA and stem mass are potential salt tolerance traits in canola and warrant further investigations and validation.