氯胁迫对幼龄茶树叶绿素含量及抗氧化系统的影响

Effects of Chloride Stress on Chlorophyll Content and Antioxidant System in Leaves of Young Tea Plant

为探讨氯胁迫对茶树的伤害机制,为幼龄茶园合理施用氯肥提供科学的理论依据,以1年生龙井43茶苗为材料,采用水培法研究了不同浓度氯离子对茶树叶片叶绿素含量、抗氧化系统的影响。结果表明:随着氯离子浓度的升高,叶绿素a、叶绿素b和总叶绿素含量均显著降低,在氯浓度为100mmol/L时,分别比CK(0mmol/L)下降了36.2%、22.7%、33.1%;SOD、POD活性均表现为先升高后降低,在氯离子浓度为40mmol/L时达到最大值,比CK分别升高10.8%和9.2%;CAT活性持续下降,最大降幅为45.4%;脯氨酸含量、过氧化氢含量及丙二醛含量均显著升高。这说明高浓度氯离子对细胞质膜系统及细胞器结构和功能产生了破坏,而在低浓度氯离子(20mmol/L)胁迫下MDA含量与CK差异不显著,说明低浓度氯未对茶树造成伤害。因此,对于幼龄茶园冲施氯肥以氯离子浓度不超过20mmol/L为宜。

In order to investigate the inj ury mechanism of chlorine stress to tea plant and provide the scientific reference for reasonable application of chlorine fertilizer to young tea plant,1-year-old seedlings of the Longjing 43 variety of tea（Camellia sinensis L.）were grown hydroponically to study the effect on chlorophyll content and antioxidant system at different concentrations of chlorine（Cl ）.The results showed that the content of chlorophyll a,chlorophyll b and total chlorophyll decreased significantly with Cl concentration increasing;their contents decreased by 36.2%,22.7% and 33.1% compared to CK（0 mmol/L）respectively at 100 mmol/L Cl.SOD, POD activities showed an initial increase followed by a decrease with Cl concentration increasing, reached their peaks when the Cl concentration was 40 mmol/L,and their activities increased by 10.8% and 9.2% compared to CK respectively.CAT activity decreased continuously with Cl concentration increasing and it decreased largest by 45.4% compared with the control at 100 mmol/L Cl.At the same time,the contents of MDA,H2 O2 and proline increased obviously with the increasing of Cl concentration.These results suggested that at higher Cl concentrations,the Cl stress could mangle the cytomembrane system,and functions of the maj or organelles of tea plant. However,slight Cl stress hardly damaged young tea plant because MDA content had not significant difference at low Cl concentration （20 mmol/L ） compared to CK.Therefore,Cl fertilizer concentration applied to young tea plant should be less than 20 mmol/L.