Cd2+对狗牙根、假俭草种子萌发及幼苗生长的影响

探讨了Cd²⁺浓度对狗牙根与假俭草种子萌发和幼苗生长的影响。结果表明,两草种种子的发芽势、发芽率、发芽指数、活力指数、根长以及幼苗长度均随Cd²⁺浓度的升高而降低;叶片叶绿素含量随Cd²⁺浓度的升高略有降低;叶片丙二醛(MDA)含量随Cd²⁺浓度的升高呈先降后升趋势;狗牙根过氧化氢酶(CAT)活性随Cd²⁺浓度升高呈先升高后降低趋势, 在5.0 mg/L时显著高于CK, 假俭草各处理浓度的CAT活性均低于CK;两草种的过氧化物酶(POD)活性随Cd²⁺浓度的升高呈先升高后降低趋势, 并在10.0 mg/L时达到峰值;Cd²⁺浓度在5.0,10.0,20.0,40.0 mg/L时, 狗牙根和假俭草多酚氧化酶(PPO)活性均高于CK, 两草种PPO活性随Cd²⁺浓度的升高都呈先升高后降低趋势。两草种对Cd²⁺均有一定的耐受能力, 狗牙根耐受能力大于假俭草, 二者均可以应用于Cd²⁺轻度污染土壤。

Effects of Cd2+on the seed germination and seedling growth of Cynodondactylon and Eremochloaophiuroides

The effect of Cd²⁺ concentration on the germination and growth of Cynodon dactylon and Eremochloa ophiuroides has been studied. The results showed that the seed germination rate, germination vigor, germination index, vigor index, root length and seedling length of the two turfgrass species decreased with increases in Cd²⁺ concentration. Chlorophyll content in leaves decreased slightly and the MDA contents in leaves showed a rising trend after an initial drop with increasing Cd²⁺ concentration. The CAT activities of C. dactylon increased at first and then decreased with increasing concentrations. At a Cd²⁺ concentration of 5.0 mg/L, CAT activities were significantly higher than that of CK, while the CAT activities of E. ophiuroides in all treatments were lower than that of CK. The POD activities of the two turfgrass species increased at first and then decreased with increasing Cd²⁺ concentration, reaching its peak at 10.0 mg/L. The PPO activities of C. dactylon and E. ophiuroides were higher than CK when the concentrations were at 5.0, 10.0, 20.0 and 40.0 mg/L. With increasing Cd²⁺ concentrations, the PPO activities of both species showed a declining trend following an initial rise. The two turfgrass species have a certain degree tolerance of Cd²⁺, with the tolerance of C. dactylon greater than that of E. ophiuroides. Both turfgrass species can thus be used in soils with low levels of Cd²⁺ pollution.