砷、镉胁迫对茶树生育的影响

采用室内水培法,分别研究了砷(As)、镉(Cd)单一胁迫对茶树新梢生育和光合作用的影响以及毒害症状,结果表明:随着砷胁迫浓度的升高,茶树发芽和新梢生长受到严重抑制;茶树的叶绿素含量、光合速率、气孔导度和蒸腾速率均随砷胁迫浓度的升高而降低,同时各胁迫处理的茶树均出现明显的受害症状。镉胁迫的茶树在处理80 d后出现轻微毒害症状,低浓度镉胁迫(≤3 mg/L)对新梢生长、叶绿素合成和光合作用有一定促进作用;当胁迫浓度≥4 mg/L时,则表现负面影响。砷胁迫的毒害作用强于镉胁迫。

Effects of As and Cd Stress on the Growth of Tea Plants

The effects of As and Cd stress on the growth of twigs,the photosynthesis of leaves as well as the poison symptom in tea plants were studied using water culture methods.The results showed that,with the increase of As+ concentration,the germination of tea plants and the growth of twigs were severely restrained,and the content of chlorophyll,photosynthetic rate,stomatic conductance and transpiration rate decreased.When tea plants were cultured in Cd 2+ solution for 80 days,light damaged-symptoms were observed.The growth of twigs,synthesization of chlorophyll and photosynthesis of leaves were accelerated when Cd2+≤3mg/L,but they were restrained when Cd2+≥4mg/L.Generally,the damage caused by As stress to tea plants was more obvious than the damage caused by Cd stress.