除草剂对毛桃幼苗生长与光合的影响

 以毛桃Prunus persica（L.）Batsch.] 1年生幼苗为材料，研究土施除草剂对其生长发育、根系结构以及光合作用等的影响。结果表明：土施百草枯后，毛桃幼苗根系细胞电解质渗透率在初期显著升高，随后受损伤程度减轻；处理后40 d叶片蒸腾速率升高，叶片水分利用率、地上部干物质量显著降低。施用草甘膦对幼苗外部形态影响较明显，处理后7 d，幼叶变黄、向上卷曲，根系细胞电解质渗透率始终显著高于清水处理对照；处理后40 d，根总体积、总根长、总表面积以及根尖数显著减少，叶片净光合速率、气孔导度、蒸腾速率下降，植株干物质积累量也显著降低，表明草甘膦可通过根部传导危害地上部，桃园应尽量避免草甘膦等内吸性除草剂的使用。

Effects of Herbicides on Growth and Photosynthesis of Prunus persica Seedlings

Taking one-year old peachPrunus persica（L.）Batsch.] seedlings as test materials. This paper studied the effects of herbicides（glyphosate and paraquat）on growth and development，root structure and photosynthesis in peach seedlings. The results showed that at early days after spraying paraquat，the electrolyte leakage rate of roots was raised，after that，the damages to the roots was reduced as time went on afterward. On the 40th day after spraying paraquat，the leaf transpiration rate（Tr）increased while the water utilization efficiency（WUE）decreased and total aboveground dry matter lower than that of control. Glyphosate showed obvious influence on external morphology of peach. On the 7th day after spraying glyphosate，the young leaves getting yellow，curling upwards. The electrolyte leakage rate of roots was always higher than that of the control. On the 40th day after spraying glyphosate，the total length，volume，surface area and tip number of roots were decreased significantly. The leaf photosynthetic rate（Pn），transpiration rate（Tr）and stomatal conduction（Gs）decreased. The glyphosate treatment also significantly inhibited dry matter accumulation of peach. These results imply the glyphosate have a influence on plant aboveground through root transduction. We should avoid using systemic herbicides in peach orchard.