Effects Of Exogenous Calcium Treatment On Growth Of Potato(solanum Tuberosum L.) Seedlings Under Weak Light

The potato（Solanum tuberosum L.）is an important food and vegetable crop,and it is one of the high-yield crops with good prospects for development.In the early stage of potato growth,under weak light stress,plant growth is easily impaired,which not only inhibits photosynthesis but also ultimately reduces yield and quality.Therefore,the study on the growth and development characteristics of potato plants under low light is of great significance for the high quality and high yield of winter potato in Jianghuai region.In this study,the potato variety"Zhushu 20"was used as the test material.After the six-leaf and one-heart period,the plants with the same growth trend were selected for low-light treatment and exogenous calcium（CaCl₂）treatment.At the same time,the control group was set up,cultivated in the artificial climate chamber,and treated once every three days at the same time.At the same time,relevant indicators were measured and sampled.The main work completed and the main findings are as follows:1)Compared with normal light,weak light stress can cause potato plant shape reconstitution,resulting in a larger increase in plant height,a slower increase in stem diameter,and a lower relative water content in leaves.Exogenous CaCl₂ alleviated the morphological abnormal growth of potato plants caused by weak light stress by decreasing the growth trend of potato plants,increasing stem diameter and increasing leaf water content,and made the plants more robust.2)Compared with normal light,the light energy absorbed,transmitted and dissipated by the unit response center of potato leaf under weak light stress increased,and the light energy absorbed,transmitted and dissipated by unit reaction center of potato leaf was reduced,and the photochemical activity was reduced.Significantly lower.After exogenous calcium treatment,the light energy absorbed,transmitted,and dissipated in the functional leaves of the potato did not alleviate.3)Compared with normal light,the content of auxin（IAA）and gibberellin（GA）,brassinolide（BR）and ethylene（ETH）in potato functional leaves under low light stress increased significantly.After exogenous spraying of calcium ions（CaCl₂）,the contents of several endogenous hormones in the functional leaves of potato increased.4)Compared with normal light,the stability of cell membrane lipids of potato functional leaves decreased under low light stress,and malondialdehyde（MDA）and ROS levels(including H₂O₂ content and O^2-production rate)increased significantly.After exogenous CaCl₂ spraying,the levels of MDA and ROS(including H₂O₂ content and O^2-production rate)under low light intensity of potato significantly decreased.5)Compared with normal light,the soluble sugar content,soluble protein content and proline content of potato functional leaves under low light stress were significantly reduced,and the ability of osmotic adjustment was reduced.Exogenous CaCl₂ spray significantly increased the level of osmolarity substances in potato leaves.