The effects of waterlogging stress on plant morphology, leaf physiology and fruit yield in six tomato genotypes at anthesis stage

Abstract

Waterlogging stress caused by concentrated and heavy rainfall has become an increasingly popular abiotic stress, especially for tomato production. The aim is to clarify the leaf physiological and biochemical responses as well as flower and fruit set of tomato plants at reproductive stage under waterlogging stress. Six tomato genotypes including 'MIX-002', 'LA4440', 'Fenbeibei', 'Hezuo 908', 'Jinzhu' and 'Ruifen 882' at anthesis stage were treated under control and waterlogging stress. We found that plant height, stem diameter, inflorescences number, single fruit weight and fruit weight per plant of all the six tomato genotypes significantly decreased under waterlogging stress as compared with the control. Chlorophyll a content of 'MIX-002', 'LA4440' and 'Jinzhu' and total chlorophyll content of 'MIX-002', 'LA4440' and 'Ruifen 882' were significantly lower under waterlogging conditions than the control. Waterlogging stress induced low net photosynthetic rate of 'MIX-002' and decreased transpiration rate of six genotypes except 'Fenbeibei'. Antioxidant enzymes activity and proline content responded to waterlogging stress by up/down regulation, resulting in high malondialdehyde and H2O2 content in leaves of six genotypes. Overall, waterlogging stress caused low gas diffusion, negatively affected pigment content, decreased transpiration rate, and induced antioxidant system disorder in tomato plants at anthesis stage. These adverse effects contributed to few buds and flowers and finally resulted in yield loss of tomato plants under waterlogging conditions. The significant correlation between malondialdehyde and H2O2 content and tomato yield indicated that the malondialdehyde and H2O2 content in leaves could be applied to predict the tomato yield under waterlogging condition.