Abstract:

To investigate the effects of sea rice cultivation on microbial community of coastal saline soil and its relationship with environmental factors， the soils with 0.2% and 0.6% salt concentration were as materials， in which sea rice was grown as treatment groups （S1 and S2） and no plant as control groups（CK1 and CK2）. The chemical properties， nutrient content and microbial community structure of soil under different treatments were determined. The results showed that， after planting sea rice， the contents of humus， available phosphorus and available potassium significant increased， which peaked at 19.26 g·kg^-1， 40.61 mg·kg^-1， 98.33 mg·kg^-1 and 17.42 g·kg^-1， 34.79 mg·kg^-1， 88.69 mg·kg^-1 under S1 and S2 treatments in the heading stage， respectively. At the same time， the contents of alkali-hydrolytic nitrogen， ammonium nitrogen and nitrate nitrogen of soil significantly increased after planting sea rice， and the contents were the highest at heading stage. Compared with the control group， the microbial biomass carbon （MBC）， microbial biomass nitrogen （MBN） and microbial respiratory activity （MR） under treatment groups increased significantly， which increased 190.42%， 234.13% and 93.33% in S1 treatment， 195.33%， 184.26% and 108.14% in S2 treatment， respectively. At the same time， the planting sea rice had significant effects on the diversity of coastal saline soil microbial community structure. The relative abundances of dominant microfloras under S1 treatment were significantly higher than those under S2 treatment. Under S1 treatment， the relative abundances of Burkholderiacea， Chitinophagacea， Methylophilacea， Pyrinomonadaceae， Sphingomonadaceae， Blastocatellaceae increased significantly by 75.63%， 4.01%， 54.67%， 65.03%， 99.11%， 49.93%， 119.75%， respectively. Under S2 treatment， the relative abundances of Burkholderiacea， Methylophilacea， Blastocatellaceae， Nitrosomonadaceae increased significantly by 29.83%， 28.17%， 148.84%， 44.81%， respectively. Correlation analysis showed that pH of soil was extremely significant positively correlated with the relative abundance of Burkholderiaceae and Methylophilaceae， while the contents of Humus， the soil alkali-hydrolytic nitrogen， ammonium nitrogen， nitrate nitrogen were extremely significant positively correlated with the relative abundance of Pyrinomonadaceae and Blastocatellaceae.

Key words: sea rice, saline soils, soil chemistry, microbial biomass, microbial community structure

摘要：

为研究种植海水稻对滨海盐土微生物群落的影响及其与环境因子间的关系，以不种植海水稻的含盐0.2%（CK1）和0.6%（CK2）的土壤为对照组，以在0.2%和0.6%盐度种植‘海稻86’的土壤为处理组（S1、S2），研究不同处理下土壤的化学性质、养分含量和微生物群落结构。结果表明，种植海水稻后，土壤腐殖质、速效磷、速效钾含量较对照组显著提升，在抽穗期，S1和S2处理分别为19.26 g·kg^-1、40.61 mg·kg^-1、98.33 mg·kg^-1和17.42 g·kg^-1、34.79 mg·kg^-1、88.69 mg·kg^-1；同时，种植海水稻提升了土壤碱解氮、铵态氮、硝态氮的含量，且均在抽穗期时含量最高。种植海水稻后，处理组土壤的微生物生物量碳（microbial biomass carbon，MBC）、微生物生物量氮（microbial biomass nitrogen，MBN）含量及微生物呼吸活性（microbial respiratory activity，MR）较对照组显著增加，在抽穗期，S1处理较CK1显著增加190.42%、234.13%和93.33%；S2处理较CK2显著增加195.33%、184.26%和108.14%。同时种植海水稻对滨海盐土微生物群落结构多样性影响显著，S1处理对微生物群落优势菌相对丰度的提高显著优于S2处理。S1处理中，伯克氏菌科（Burkholderiaceae）、噬几丁质菌科（Chitinophagaceae）、嗜甲基菌科（Methylophilaceae）、吡啶单胞菌科（Pyrinomonadaceae）、鞘脂单胞菌科（Sphingomonadaceae）、芽囊藻科（Blastocatellaceae）、亚硝化单胞菌科（Nitrosomonadaceae）的相对丰度较CK1分别显著提升75.63%、4.01%、54.67%、65.03%、99.11%、49.93%、119.75%。S2处理中，伯克氏菌科（Burkholderiaceae）、嗜甲基菌科（Methylophilaceae）、芽囊藻科（Blastocatellaceae）、亚硝化单胞菌科（Nitrosomonadaceae）相对丰度较CK2分别显著29.83%、28.17%、148.84%、44.81%。相关性表明土壤pH与伯克氏菌科和嗜甲基菌科的相对丰度呈极显著正相关；土壤腐殖质、碱解氮、铵态氮和硝态氮含量与吡啶单胞菌科和芽囊藻科的相对丰度呈极显著正相关。

关键词: 海水稻, 盐土, 土壤化学性质, 微生物生物量, 微生物群落结构