假俭草和海滨雀稗对土壤铅污染胁迫的生理反应

通过盆栽试验研究了假俭草Eremochloa ophiuroides和海滨雀稗Paspalum vaginatum2种草坪植物在3 000和6 000 mg/kg铅浓度胁迫下的生理变化。结果表明,2种草坪植物在不同铅浓度胁迫下呈现明显的差异。在3 000 mg/kg铅浓度胁迫下,假俭草的叶片叶绿素含量、光化学效率和渗透势均未出现显著(P0.05)变化;处理后12 d叶片电导率显著上升,24 d叶片相对含水量显著下降;目测质量虽然在4 d时即开始显著下降,但在整个试验期间仍维持在可接受草坪质量(6.0)之上。在6 000 mg/kg铅浓度胁迫下,假俭草的所有生理指标在4 d即出现显著变化,12 d植物完全枯死。在3 000 mg/kg铅浓度胁迫下,海滨雀稗的叶片光化学效率、渗透势、叶绿素含量不仅没有下降,反而分别于12、16和24 d显著高于对照;电导率和草坪目测质量则与对照无显著差异(P0.05);叶片相对含水量虽然在12 d时出现显著下降,但在24 d时又恢复到了对照水平。在6 000 mg/kg铅浓度胁迫下,海滨雀稗的叶绿素含量未出现显著下降;叶片电导率在4 d即开始显著上升,渗透势、相对含水量和光化学效率在4 d显著下降,但分别于12、16、20和24 d恢复到对照水平;草坪目测质量虽然低于对照,但仍维持在可接受草坪质量之上。上述结果说明海滨雀稗在6 000 mg/kg浓度的土壤铅污染下仍能修复铅污染带来的伤害,其耐铅性要显著高于假俭草。

Physiological responses of seashore paspalum and centipedegrass to soil lead contamination stresses

The physiological responses to soil lead contamination stresses at 3 000 mg/kg and 6 000 mg/kg were studied in a pot experiment for two turfgrasses species centipedegrass(Eremochloa ophiuroides) and seashore paspalum(Paspalum vaginatum).The results showed that there were significant differences between two turfgrass species under the two lead stress regimes.Under 3 000 mg/kg Pb2+ stress,the leaf chlorophyll content,Fv/Fm and osmotic potential in centipedegrass did not changed significantly,while the electro...