铅胁迫对茶树生长及叶片生理指标的影响

Lead Stress on Growth of Tea Trees and Physiological Index in Leaves of Tea

通过盆栽试验,研究了不同土壤铅浓度对茶叶生长及叶片生理特性的影响。结果表明,随着土壤铅浓度的升高,夏茶叶绿素含量显著下降,并有失绿现象,茶树生长受到一定程度的抑制。春茶叶绿素含量呈上升趋势,夏茶叶绿素含量呈先增加后降低的趋势。当铅浓度为100mg·kg-1时,叶绿素含量达到最大值2.93mg·g-1;铅浓度为1500mg·kg-1时,叶绿素含量达到最小值2.28mg·g-1;随铅浓度增加,叶片中游离脯氨酸、丙二醛含量显著增加,两者与铅浓度呈显著正相关,春茶的相关系数分别为0.922(P<0.01)和0.880(P<0.01),夏茶的相关系数为0.871(P<0.05)和0.971(P<0.01),且夏茶中的游离脯氨酸、丙二醛含量大于春茶。铅对春茶、夏茶中可溶性糖的合成有一定的抑制作用,相关系数分别为-0.715(P<0.01)和-0.912(P<0.01)。在铅浓度为0～200mg·kg-1时,春茶可溶性糖有小幅度增加;在铅浓度为200mg·kg-1时,春茶、夏茶可溶性糖含量都同时达到最大值。

Effects of different lead concentrations on growth and physiological index in leaves of tea were studied with the tea cultured in pots. The results showed that, with the increasing concentrations of lead, lead had a significant effect to the yield of summer tea, and the green deficiency symptoms were visible, and the growth of tea was inhibited. The chlorophyll（Chl） content of spring tea was enhanced with the increasing concentrations; The Chl content of summer tea was first stimulated and then inhibited with increasing concentration of lead. When the lead concentration in nutrient solution was 100 mg. kg-1, the Chl content reached the maximum 2.93 mg. g-1 and when the concentration was 1 500 mg. kg-1, Chl content reached the minimum 2.28 mg. g-1. Meanwhile, with increasing concentration of lead, the free praline and malondialdehyde（MDA） content in leaves were significantly enhanced, There was a positive correlation between the free praline, MDA content and the lead concentration, which the coefficient of correlation is 0.922（P〈0.01 ） and 0.880（P〈0.01 ） respectively on spring tea, and, the coefficient of correlation is 0.871 （P〈0.05） and 0.971 （P〈0.01） on summer tea,and then the summer tea＇s was higher than spring tea＇s; Lead would in- hibit the synthesis of soluble sugar in the tea, the coefficient of correlation is -0.715（P〈0.01 ） and -0.912（P〈0.01 ） respectively. The soluble sugar of spring tea has a little increase when the lead concentration was 0-100 mg-kg-1 and the soluble sugar of spring tea and summer tea reached the maximum at the same time when the lead concentration was 200 mg.kg-1.