Ultrasonic seed treatment and Cu application modulate photosynthesis, grain quality, and Cu concentrations in aromatic rice

Abstract

The present study investigated the effects of ultrasonic seed treatment and Cu application on grain yield, photosynthesis, grain quality, and Cu contents of aromatic rice. The ultrasonic treated and nontreated seeds of two aromatic rice cultivars, i.e., Nongxiang 18 and Meixiangzhan 2, were sown in Cu-contaminated soil with 1.5 and 3.0 g(Cu) m-2 whereas the soil without Cu application was taken as control (CK). Ultrasonic seed treatment and Cu application increased grain yield by 2.7-33.5% in Nongxiang 18 and by 12.9-20.2% in Meixiangzhan 2 owing to substantial improvements in morphophysiological and yield-related traits. Both ultrasonic seed treatment and Cu application also improved the 2-acetyl-1-pyrroline contents as a result of increased proline contents and proline dehydrogenase activity. The Cu contents in plant parts were higher in Cu-containing soil than that of CK. Overall, ultrasonic seed treatment and optimum Cu application improved aromatic rice grain yield, dry biomass, aroma, and grain quality of aromatic rice.