微生物保水剂对大花序桉幼苗生长生理及养分含量的影响

为筛选有利于大花序桉抗旱且促生效果较好的保水剂用量,以广西林科院培育的大花序桉容器苗为试材,利用盆栽试验,对比分析微生物保水剂不同用量下,大花序桉幼苗生长、光合特性及养分含量的差异及相关性。结果表明:(1)干旱胁迫下,施用保水剂可以促进大花序桉幼苗生长,施用量为5 g/株时,苗高增长量最大,分别为42.18 cm,较对照提高26.25%;(2)随保水剂用量增加,大花序桉净光合速率、气孔导度、蒸腾速率均呈现先上升后下降趋势,施用量为5 g/株时,三者达到最大,分别较对照提高100.15%、52.94%、16.87%,胞间CO_(2)浓度则呈现先下降后上升趋势;(3)叶片N、P、K、Fe、Mn、Cu、Zn等元素含量在施用量为5 g/株时最高,分别较对照高75.73%、6.38%、65.67%、209.78%、193.21%、20.34%、59.04%;(4)大花序桉苗高及地径的增长量与净光合速率、蒸腾速率、胞间CO_(2)浓度、N、P、K、Fe、Mn、Cu、Zn呈显著或极显著相关。综上,适宜的微生物保水剂用量可以缓解干旱胁迫,提高大花序桉的光合能力,促进养分吸收和苗木生长。大花序桉最适保水剂用量为5 g/株。

Security evaluation of compounded microbial flocculant

A new kind of compounded microbial flocculant (CMBF) for water and wastewater treatment has been developed through biological technology. In order to discuss its biological security, four groups of experiments, rat acute toxicity test via mouth, salmonella assay in vitro, mouse micronucleus in vivo test and teratogenesis test were conducted to evaluate its general toxicity, genotoxicity and generative toxicity. The experimental results showed that this type of compounded microbial flocculant was a substantial non-toxic substance based on the fact that LD50 value was over 10 mg/kg. The results from salmonella in vivo test and mouse micronucleus in vivo test revealed that the compounded microbial flocculant is a genetically non-toxic substance. Furthermore, compounded microbial flocculant has little effect on the growth of all the rats, and any morphologic abnormal phenomenon hasn’t appeared.