铅对芥菜种子萌发、幼苗生长及叶片光合色素含量的影响

 以福州宽杆芥菜为试验材料，以铅为变量，试验采用单因素随机设计，设9个处理，每个处理3个重复，通过种子萌发试验来研究铅胁迫对宽杆芥菜种子萌发、幼苗生长及光合色素含量的影响。结果表明：随着铅浓度的增加，宽杆芥菜种子的发芽势、发芽率、相对发芽率、发芽指数、相对发芽指数、萌发活力指数、相对萌发活力指数、苗高、主根长、侧根数、根鲜重和根干重均显著下降。当铅浓度0～200mg/L时，叶绿素a，总叶绿素和类胡萝卜素含量呈递增的趋势；当铅浓度200～1500mg/L时，这些指标下降。当铅浓度0～100mg/L时，叶绿素b含量呈递增的趋势；当铅浓度100～1500mg/L时，叶绿素b含量呈下降的趋势。总之，重金属铅抑制芥菜种子萌发和幼苗的生长，但低浓度的铅能促进芥菜叶片光合色素的积累，高浓度的铅抑制芥菜叶片光合色素的合成。

Effects of Lead on Seed Germination, Seedling Growth and Leaf Photosynthetic Pigment Contents of Brassica juncea

Taken the seed of Brassica juncea as material and lead as variable value,seed germination experiment of night treatments which had three repeats were designed to study the effect of the lead stress on the seed germination，seedling growth and leaf photosynthetic pigment contents of B. juncea. The experiment result showed that with the increasing of lead concentration, the germination vigor，germination rate，relative germination rate，germination index，relative germination index，vigor index，relative vigor index，seedling height，root length，root number，fresh weight of root and dry weight of root of B.juncea decreased obviously. With the lead concentration of 0～200mg/L,the contents of chlorophyll a, total chlorophyll and carotenoid increased; with the lead concentration of 200～1500mg/L, these indices decreased. With the lead concentration of 0～100 mg/L, the contents of chlorophyll b increased; with the lead concentration of 100～1 500 mg/L, the contents of chlorophyll b decreased. In short, lead could restrain the seed germination and seedling growth of B.juncea,but low concentration lead could help accumulate the leaf photosynthetic pigment contents of B.juncea,high concentration lead could prevent the synthesis of leaf photosynthetic pigment contents of B.juncea.