速效钾对沟叶结缕草吸收和转运Cd的影响

Effects of Available Potassium on Cadmium Accumulation in Zoysia Matrella

以耐镉植物沟叶结缕草为试材,采用盆栽模拟试验,探究土壤速效钾对沟叶结缕草吸收转运Cd过程中的影响,以及对植物株高、茎节数、茎节长等指标的关系,以期为改良植物品种提供参考依据。结果表明:第5组沟叶结缕草的株高、茎节长、茎节数、叶长、叶宽、叶片数、干质量均显著低于其它8组,其中第5组(Cd 36.11 mg·kg^(-1);Fv/Fm 0.712)与第3组(Cd 36.22 mg·kg^(-1);Fv/Fm 0.714)生长的植株在受到Cd胁迫程度近似的情况下,第5组植株的株高、茎节长、茎节数、叶宽、干质量依然显著低于第3组。第5组速效钾含量显著低于第3组(P<0.05),第3组脲酶含量显著低于第5组(P<0.05)。并且第3组的富集系数(0.96)和转运系数(0.59)与第5组的富集系数(5.07)和转运系数(0.90)也存在显著差异。通过Pearson相关分析验证,发现富集系数和转运系数均与土壤速效钾、脲酶呈正相关,与土壤pH呈负相关。其分析结果表明,土壤速效钾有助于提高沟叶结缕草对Cd的富集和转运。

Taking cadmium tolerant plants Zoysia Matrella as test material.A pot experiment was conducted to investigate the effects of soil available potassium on Cd uptake and transportation of manilagrass, and the relationship between plant height, stem node number and stem node length and other indicators, in order to povide a reference for improving the plant varieties.The results showed that there were significant differences in plant height, stem node length, stem node number leaf number leaf length and leaf width among the nine groups.The Cd concentration of the fifth group(Cd 36.11 mg·kg^(-1);Fv/Fm 0.712) was close to the third group(Cd 36.22 mg·kg^(-1);Fv/Fm 0.714) but the two groups had significant differences in plant height, stem node length, stem node number, leaf width and dry weight.There was significant difference of available potassium and urease activity between the fifth and the third groups(P<0.05);the fifth group had the lowest available potassium content;the third group had the lowest urease activity.Although the third and fifth groups had the similar total soil Cd contents, the Cd bioconcentration factors(BCF) and translocation factor(TCF) were significantly different.They were 0.96 and 0.59 or 5.07 and 0.90 respectively.Pearson correlation analysis indicated the BCF and TCF was positively correlated with available potassium and urease, negatively correlated with soil pH.The results demonstrated that soil available potassium helps to increase the accumulation and transport of Cd in manilagrass.