【作者】 刘磊；

【导师】 李彩凤；

【作者基本信息】 东北农业大学 ， 作物栽培学与耕作学， 2017， 硕士

【摘要】 甜菜（Beta vulgaris L.）是主要的糖料作物和能源作物,具有极强的耐盐碱性,研究甜菜在混合碱性盐（Na₂CO₃⁺Na HCO₃）条件下根系及其根际微生态变化,对进一步研究甜菜的根际效应奠定基础,对盐碱地的开发利用具有重要意义。本试验以甜菜品种KWS0143和Beta464为材料,在盆栽条件下,将碱性盐Na HCO₃和Na₂CO₃按摩尔比为2:1混合,按施入土壤的混合碱性盐质量设置4个处理,分别是0、5、7和9 g/kg（A0、A2、A3和A4）,处理后的土壤EC值分别为127.67、559.33、782.67、981.67,p H值分别为7.20、9.18、9.40、9.56,在该条件下对根系鲜重、干重、根系活力、根系形态,超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性、丙二醛（MDA）含量,根系内源激素含量的进行分析,并检测根系分泌物种类及含量的变化、根际微生物群落和数量,土壤酶活性的变化。研究结果如下:1.随着处理浓度的增加,甜菜幼苗出苗率下降,6月2日（1对真叶）时根系干重、鲜重和根系形态指标（长度、表面积、体积）均降低,而根系活力升高;6月16和30日（2、3对真叶）时根系干重、鲜重、根系活力和根系形态指标（长度、表面积、体积）呈先增加后减少的趋势,在A3处理下显著高于对照（P<0.05）,A4处理下显著低于对照（P<0.05）;而且KWS0143各指标高于Beta464。随着取样时间的延长,甜菜幼苗根系干重、鲜重、根系活力和根系形态指标（长度、表面积、体积）均呈上升趋势。干重、根活力和根长度、表面积、体积之间存在显著或极显著正相关关系。2.随着处理浓度的增大,甜菜根系MDA含量增加,而保护酶（SOD、POD、CAT）活性则表现为先升高后降低。6月2日（1对真叶）时IAA、BR和ABA含量随处理浓度增大而增多,ZR减少,对应的比值变化为IAA/ABA减小、BR/ABA增大和ZR/ABA降低。6月30日（3对真叶）时内源激素（IAA、ZR、BR、ABA）含量和比值变化与保护酶一致,均为先上升后下降,A3处理的活性最高,A4时活性最低,与A0差异显著。随处理时间的延长,甜菜根系保护酶（SOD、POD、CAT）活性和MDA含量均升高,内源激素中BR升高,IAA、ZR、ABA均先升后降,而对应的比值BR/ABA升高,IAA/ABA和ZR/ABA则降低。相关分析表明,保护酶（SOD、POD、CAT）与激素之间变化存在正相关关系,与IAA、ZR、BR达显著或极显著正相关。3.甜菜苗期根系分泌物被检测出共含有83种物质,其中包括烷烃、烯烃、酯类、醇类、酮、酚类、醛、酸、吡啶、噻唑、胺类、萘等,种类最多的是酯类和烷烃类。6月2日（1对真叶）时根系分泌物种类比30日（3对真叶）多46种,包括烷烃类（十四烷、十五烷、十七烷等）、酚类（2,4-二叔丁基苯酚、2,6-二叔丁基对甲苯酚等）和酯类（邻苯二甲酸丁基酯1-甲基壬基酯、邻苯二甲酸丁基酯2-乙基己基酯、邻苯二甲酸二异丙酯等）。两个取样时期检测出根系分泌物种类均为A3最多、A4最少;且品种KWS0143的分泌物种类比品种Beta464丰富。4.不同处理的土壤脲酶、碱性磷酸酶、过氧化氢酶活性和微生物总量均是A3最高,均存在显著差异;随着时间的延长,脲酶先升后降、碱性磷酸酶上升、过氧化氢酶先降后升。根际土壤微生物数量表现为:细菌>放线菌>真菌。在30日（3对真叶）时细菌数量A3>A2>A0>A4、真菌A3 A2>A0>A4和放线菌A0>A3>A2>A4,差异性显著;KWS0143的根际脲酶、碱性磷酸酶、过氧化氢酶活性及细菌和放线菌数量高于Beta464,真菌数量则为K<B。相关分析表明,脲酶活性同细菌数量和微生物总量呈显著正相关,过氧化氢酶活性与放线菌数量呈极显著正相关关系。更多还原

【Abstract】 Sugar beet（Beta vulgaris L.）is the main sugar crop and energy crop,with strong salt tolerance.The effect of mixed alkaline salt on the changes of root and Rhizosphere micro ecology under was studied.Our results will provide theoretical reference for the further study on the rhizospheric effect of sugar beet.The pot experiment was conducted with KWS0143 and Beta464 as test materials.alkaline salt Na HCO₃ and Na₂CO₃ molar ratio of 2:1 mixture was applied to the soil with four levels of salt concentration,0,5,7 and 9 g/kg,marked with A0,A2,A3 and A4,respectively.The corresponding EC value of the four treatments was 127.67,559.33,782.67,and 981.67,respectivy,and the corresponding p H value was 7.20,9.18,9.40,and 9.56,respectively.some root indice were determined including fresh root weight,dry root weight,root activity,root morphology,superoxide dismutase（SOD）,peroxidase（POD）,catalase（CAT）activity,malondialdehyde（MDA）content,endogenous hormone content,root extracs type and content,rhizosphere microbial community and quantity,and soil enzyme activity.The results are as follows:1.The germination rate of sugar beet seedlings decreased with the increase of alkaline concentration.The root dry weight,fresh weight and root morphology index（length,surface area,volume）decreased on June 2nd,while root activity increased;the root dry weight,fresh weight,root activity and root morphological index（length,surface area,volume）first increase,and decreased on June 16 and 30.The value of those indice at A3 was significantly higher than control（P<0.05）,and at A4 was significantly lower compared to control and the value of those indice for KWS0143 was higher than Beta464.over the sampling time,the dry root weight,fresh root weight,root activity and root morphological index（length,surface area,volume）of the root of the beet seedlings showed an increasing trend.There was significantly positive correlation among dry root weight,root activity and root length,root surface area,and root volume.2.With the increase of alkcline concentration,MDA content increased,while the activity of protective enzymes（SOD,POD,CAT）first increased,and then decreased.The content of IAA,BR and ABA increased with the increase of alkaline concentration,while ZR decreased.the ratio of IAA/ABA decreased,BR/ABA increased and ZR/ABA decreased with the increase of treatment concentration on June 2nd.The contents of endogenous hormones（IAA,ZR,BR,ABA）and the ratio of the 3 true leaves were all the same as those of the protective enzymes on June 30 th.All of them were first increased and then decreased,the activity at A3 was highest,and the activity with A4 was lowest,which was significantly different from A0.Over the sampling time,the MDA ontent and activity of root protective enzymes（SOD,POD,CAT）increased.Endogenous hormone BR increased,while IAA,ZR,and ABAl first increased,and then decreased.the corresponding ratio of BR/ABA increased,IAA/ABA and ZR/ABA decreased.Correlation analysis showed that there was positive correlation between the activity protective enzymes（SOD,POD,CAT）.correlation beween hormone content and content of IAA,ZR,BR was significantly or extremely significantly positive.3.83 of types sugar beet root extracts were detected,including alkanes,alkenes,esters,alcohols,ketones,phenols,aldehydes,acids,pyridine,thiazole,amines,naphthalene and so on.The most common types are of esters and alkanes.there are 46 more kinds of root extracts on 2nd day than on 30 th day,including alkanes（fourteen alkanes,fifteen alkanes,seventeen alkyl phenols（2,4-）,tert butyl phenol,2,6-Di tert butyl p-cresol etc.）and esters（PAEs two formic acid butyl ester 1-methyl nonyl ester,phthalic acid butyl ester two 2-ethylhexyl phthalate,two formic acid and two isopropyl）.At the two sampling periods,the root extracts were hihgest at A3,lowest at A4 and the types of root extracts for KWS0143 were higher than Beta464.4.Activity of soil urease,alkaline phosphatase,catalase and microorganism amount was highest at A3,there was significant difference among four treatments.Over sampling time,urease activity decreased,catalase activity rose,and alkaline phosphatase activity first rose and then decreased.The number of microorganisms in rhizosphere soil was as follows: bacteria > actinomycetes > fungi.On 30 th day（3 pairs of leaves）,the number of bacteria was A3>A2>A0>A4,fungi was A3>A2>A0>A4 and Actinomyces was A0>A3>A2>A4,significant difference.The urease,alkaline phosphatase,catalase activity and the number of bacteria and actinomycetes in rhizosphere of KWS0143 were higher than that of Beta464,and the number of fungi was K<B.Correlation analysis showed that there was significantly positive correlation between urease activity and the number of bacteria and the total amount of microorganisms.Catalase activity was positively correlated with the number of Actinomycetes.更多还原