地面覆盖和水分胁迫对胡萝卜叶片光合特性的影响

摘要

The effects of water stress and mulching on leaf gas exchange and chlorophyll content of car-rot were studied under field condition using'cv.Xinxiusanhong'as the material.The results showed that the chlorophyll content decreased constantly as water stress prolonged,but increased first and then decreased as soil temperature increased.The content of chlorophyll was more sensitive than other parameters to soil temperature change.Net photosynthetic rate and stomatal conductance were significantly higher under clear plastic mulching than under black or no mulching.Enough soil moisture content benefited a higher photo-synthetic rate of leaf in late stage of root enlargement.It was suggested that carrot cultivation with clear plastic mulching maintains soil temperature and moisture.Irrigation amount during root enlargement should be 325~450 m3/hm2 .%以胡萝卜品种“新秀三红”为材料，在大田条件下研究了不同水分胁迫及不同覆盖方式对胡萝卜光合特性的影响.结果表明：胡萝卜叶片叶绿素含量随水分胁迫程度加剧和时间延长显著降低，较高的土壤温度有利于缓解水分胁迫下肉质根膨大后期叶绿素降低的趋势.透明膜覆盖条件下，胡萝卜叶片净光合速率和气孔导度显著大于不覆盖和黑色膜覆盖，充足的土壤水分条件有利于维持肉质根膨大后期胡萝卜叶片较高的光合能力.冷凉地区胡萝卜栽培应该采用透明膜覆盖，以利于提高土壤温度、保持土壤水分.肉质根快速膨大期次灌水量应维持在325~450 m3/hm2.