摘要
为更好地将保水剂应用到干旱山地的容器苗造林中,以丙烯酰胺-丙烯酸钾交联共聚物型保水剂作为供试材料,设置育苗时(NS)和造林时(AS)各加4.0 g保水剂的两种保水剂应用方式,利用传统的平板计数法和现代的末端限制性片段长度多态性分析(Terminal restricti on fragment length polymorphism,T-RFLP)技术,研究NS和AS对侧柏容器苗造林一年后根际土壤微生物种群结构及对侧柏干旱适应能力的影响.结果表明:保水剂可显著提高侧柏根际土壤细菌、真菌的数量和微生物量碳、氮的含量,且NS处理根际土壤的细菌数量和微生物量碳分别比AS处理提高21.65%和8.04%;保水剂及其应用方式对造林初期侧柏根际土壤的细菌群落结构产生较大影响,保水剂显著增加了根际土壤中细菌群落结构的多样性,NS处理具有最高的丰富度指数、多样性指数和最低的优势度指数;此外,同对照相比,NS处理还显著提高了侧柏容器苗的造林成活率、叶片的净光合速率和相对含水量,降低了相对电导率;同AS处理相比,NS处理的造林成活率和叶片相对含水量分别提高了11.64%和8.33%,而相对电导率降低(降低12.19%).综上说明,保水剂通过改善侧柏容器苗根际土壤的微生物种群结构而提高植物的干旱适应能力,利用添加保水剂的容器苗造林具有更好的应用效果.
This paper discusses the effects of super-absorbent polymer（SAP） on biological activity in the rhizosphere soil and drought resistance of platycladus orientalis container seedlings to verify the utilization suitability of SAP for container seedlings in arid mountainland afforestation.Acrylamide acrylic acid potassium cross-linked copolymer was used as SAP in this study.Four afforestation treatments were designed,including NS（4.0 g SAP added in the nursery substrate） and AS（4.0 g SAP added during afforestation）.The effects of SAP and its utilization on microbial populations,diversity of bacterial community structure in the rhizosphere soil of Platycladus orientalis,and the drought resistance of P.orientalis container seedlings at the initial afforestation stage were studied by the traditional plate culture method and the modern terminal restriction fragment-length polymorphism analysis.The results showed that SAP addition significantly increased bacterial and fungal populations,as well as soil microbial biomass carbon and biomass nitrogen contents in the rhizosphere soil of P.orientalis.The bacterial populations and soil microbial biomass carbon content in the NS treatment were 21.65%and 8.04%,respectively,higher than in the AS treatment.SAP and its utilization was found to significantly affect the bacterial community structure.The diversity of the bacterial community structure in rhizosphere soil of P.orientalis was significantly increased by SAP addition.Among the 3 treatments,the highest Margalef and Shannon indexes and the lowest Simpson index were observed in the NS treatment.SAP addition also increased the survival rate,net photo synthetic rate,and relative water content,but decreased the relative electric conductance of the leaves of P.orientalis container seedlings.The survival rate and relative water content in the AS treatment was 11.64%and 8.33%,respectively,higher than in the NS treatment,whereas the relative electric conductance was 12.19%lower.Therefore,SAP addition and its utilization in arid mountain afforestation has the potential to alleviate drought stress by improving biological activity in the rhizosphere soil of P.orientalis.Addition of SAP is more effective in the nursery substrate than during afforestation.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2016年第1期43-48,共6页
Chinese Journal of Applied and Environmental Biology
基金
山东省科技发展计划项目(2010GSF10621)
山东省农业重大应用技术创新项目资助~~
关键词
保水剂
侧柏容器苗
造林
根际
微生物种群结构
干旱适应能力
super-absorbent polymer
Platycladus orientalis container seedlings
afforestation
rhizosphere
community structure
drought resistance
