水稻旱育壮秧的根际生态学特性分析  

Ecological characteristics of rice rhizosphere of dry-raised seedlings

作　　者：张志兴[1,2] 林芸青 戴沛良 李洲[2] 李忠[2] 林文雄[1,2] 

机构地区：[1]福建农林大学生命科学学院,福州350002 [2]福建农林大学农业生态研究所,福州350002

出　　处：《中国生态农业学报》2015年第12期1552-1561,共10页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金项目(31401306);福建省自然科学基金项目(2012J01075;2013J01092)资助~~

摘　　要：旱育秧是水稻高产栽培中的关键技术之一,具有省水、省种、省工、省肥、增产、早熟等特点。本研究采用大田试验,通过比较旱育秧与水育秧根际土壤生态因子及细菌群落多样性的变化,并结合地上部秧苗的形态特征,探讨旱育壮秧形成的根际生态学特性。研究结果表明,旱育方式下秧苗株高较水育秧苗矮32.31%,但植株地上部干重、根长、根干重、根冠比、白根数分别提高3.02%、21.99%、18.93%、15.10%、200.00%。根际土壤生态因子监测表明,旱育秧土壤含水量为15%-17%;与水育秧相比,土壤p H降低7.94%,电导率提高244.62%,温度上升2-3℃。旱育秧根际土壤中的磷酸单酯酶、蔗糖酶、脲酶、过氧化氢酶、脱氢酶活性分别比水育秧高166.66%、518.85%、131.98%、102.70%、84.36%,但硝酸盐还原酶活性却下降72.95%,这有利于土壤物能转化,提高土壤养分的有效性,表现为土壤有机质、硝态氮、铵态氮、速效钾、有效磷含量分别比水育秧高89.27%、320.11%、56.95%、50.85%、184.75%。细菌16S r DNA测序表明旱育秧苗根际土壤细菌Chao1指数和香农指数显著高于水育秧。菌群分析发现,旱育栽培下变形菌门α-变形菌纲和γ-变形菌纲,拟杆菌门,绿弯菌门,硝化螺旋菌门,酸杆菌门,芽单胞菌门,浮霉菌门和放线菌门比例上升,而厚壁菌门,变形菌门β-变形菌纲的比例下降。对土壤细菌优势群落的功能分析发现,旱育秧能够显著促进根际与土壤养分转化密切相关的硝化细菌、固氮菌、氨氧化菌、光合细菌、解磷菌、解钾菌的繁殖。同时,旱育秧根际土壤中与根系生长密切相关的根际促生菌的数量也显著提高。可见,旱育秧栽培方式通过控制土壤中水分的含量,调控秧苗根际土壤p H、电导率和温度,改善土壤生态环境,增强了根际土壤中与营养转化循环相关的优势菌群的数量比例,进而有利于健壮秧苗的形成。The dry-raising technique at rice seedling stage is an important cultivation method of rice that not only saves water,but also favors high yield production. To study the ecological characteristics of rice rhizosphere soils of dry-raised seedlings,the plant morphological index, ecological factor, soil nutrient effectiveness and bacterial community diversity of rhizosphere soils were investigated in a paddy field. The results showed that compared with moist-raised seedlings, shoot dry weight, root length, root dry weight, root-shoot ratio and white root number of dry-raised seedlings increased by 3.02%, 21.99%, 18.93%,15.10% and 200.00%, respectively, but plant height decreased by 32.31%. Monitoring of ecological factor showed that soil water content of dry-raised seedlings was 15% ？ 17%. Under dry-raising condition, soil p H was decreased by 7.94% andelectrical conductivity and temperature were decreased soil by 244.62% and 2？3 ℃, respectively, compared with those under moist-raising condition. The activities of phosphatase, invertase, urease, catalase and dehydrogenase in rhizosphere soils also increased by 166.66%, 518.85%, 131.98%, 102.70% and 84.36%, respectively, under dry-raised system at rice seedling stage,while nitrate reductase decreased by 72.95%. Dry-raising condition favored the conversion of soil organic matter and energy.This in turn increased soil organic matter, NO3^--N, NH4^＋-N, available K and available P in rhizosphere soil of dry-raised seedlings respectively by 89.27%, 320.11%, 56.95%, 50.85% and 184.75%. Finally, 16 s RNA high-throughput sequencing analysis showed that Chao1 and Shannon-Wiener index for bacterial was higher in rhizosphere soil of dry-raised seedlings than those of moist-raised seedlings. Analysis of soil microorganism biota revealed that the proportions of Alphaproteobacteria,Gammaproteobacteria, Bacteroidetes, Chloroflexi, Nitrospirae, Acidobacteria, Gemmatimonadetes, Planctomycetes and Actinobacteria increased in rhizosphere soil of dry-raised seedlings, while the

关 键 词：水稻 旱育秧 根际土壤 生态因子 细菌 群落多样性 

分 类 号：S314[农业科学—作物栽培与耕作技术]