2种植物秸秆浸提液对水绵生长的抑制作用

山鹰; 王丽卿; 张玮; 顾琬雯

摘要: 研究了不同质量浓度（4、8、12、16和20 mg•L^-1）水稻（Oryza sativa）和再力花（Thalia dealbata）秸秆水浸提液对水绵（Spirogyra sp.）生长的抑制作用。结果显示, 试验96 h后各处理组浸提液对水绵的生长均有抑制作用, 随着浸提液浓度的增大，水绵细胞叶绿素a含量逐渐降低，显示出明显的剂量-效应关系。再力花ρ（96 h,EC₅₀）为6.85 mg•L^-1，水稻ρ（96 h,EC₅₀）为11.27 mg•L^-1，表明再力花秸秆浸提液对水绵的毒性强于水稻。水绵细胞中MDA累积含量与水稻浸提液浓度之间呈显著正相关（P＜0.01,r=0.977）,与再力花浸提液浓度之间呈显著正相关（P＜0.01,r=0.964）。各浓度再力花浸提液处理组水绵细胞中MDA累积含量均高于水稻处理组。当ρ（浸提液）为20 mg•L^-1时,再力花处理组MDA累积含量最高，达1.884 μmol•g^-1，比相同浸提液浓度水稻处理组MDA累积含量高105.20%；电解质外渗率也表现出基本相同的变化趋势，即除ρ（浸提液）为0和4 mg•L^-1以外，其他4个再力花浸提液浓度组水绵电解质外渗率均高于相应水稻浸提液浓度组。水绵的PS II最大光能转换效率（F_v/F_m）、PS II实际光能转化效率（Φ_PSⅡ）和最大电子传递效率（η_e,t,max）的变化与浸提液浓度之间均呈负相关关系。将ρ（浸提液）为20 mg•L^-1时与为0 mg•L^-1时相比，水稻处理组水绵F_v/F_m下降96.58%，再力花处理组下降82.24%；水稻处理组水绵Φ_PSⅡ下降96.74%，再力花处理组下降96.17%；水稻处理组水绵η_e,t,max下降84.56%，再力花处理组下降43.40%。上述结果表明这2种植物秸秆浸提液对控制水绵的生长具有一定的潜在价值。

Abstract: Effects of extracts, varying in concentration (4, 8, 12, 16, 20mg•L^-1) from Oryza sativa and Thalia dealbata straws inhibiting growth of Spriogyra sp. were studied. Results show that the extracts in all the treatments displayed inhibitory effects on Spirogyra sp.after 96h of exposure, with content of chlorophyll in Spriogyra sp. cells decreasing with the increasing of extract concentration, demonstrating a significant dose-effect relationship. The 96h,EC₅₀ of T. dealbata extract was 6.85mg•L^-1 and of O. sativa extract, 11.27mg•L^-1, obviously showing that the former is higher than the latter in toxicity to Spriogyra sp.. Extremely significant positive relationships were observed between of MDA content in Spriogyra sp. cells and concentration of O. sativa extract (P＜0.01,r=0.977), and between MDA content and concentration of T. dealbata extract (P＜0.01,r=0.964), too. MDA contents were higher in T. dealbata treatments than in O. sativa treatments, regardless of extract concentration. Among all the treatments, the one of T. dealbata extract, 20 mg•L^-1 in concentration, had the highest MDA content, reaching 1.884μmol•g^-1 or being 105.20% higher than that in the treatment of O. sativa extract the same in concentration. A similar trend was also observed with electrolyte exosmosis (R_EL), that is to say, R_EL is higher in all the T. dealbata treatments than in their corresponding O. sativa treatments, except for the treatments 0 or 4 mg•L^-1 in extract concentration. The PSⅡ maximal photochemical efficiency (F_v/F_m), the PSⅡactual photochemical efficiency (Φ_PSⅡ) and the maximal relative electron transport rate (η_e,t,max) of Spriogyra sp. were found to be negatively related to concentration of the extracts. In the treatments of O. sativa extract, F_v/F_m of Spriogyra sp. was 96.58%, Φ_PSⅡ,96.74% lower and η_e,t,max, 84.56% lower in the treatment, 20 mg•L^-1 in concentration than in that 0 mg•L^-1 in concentration, while in the treatments of T. dealbata extract F_v/F_m was 82.24% lower, Φ_PSⅡ,96.17% lower and η_e,t,max, 43.40% lower in the former than in the latter. Alll the above findings suggest that the extracts of the straws of the two plants have some potential value in controlling growth of Spriogyra sp. in water environment.

2种植物秸秆浸提液对水绵生长的抑制作用

Inhibitory Effects of Extracts From Straws of Two Plants on the Growth of Spirogyra sp.