共查询到19条相似文献，搜索用时 546 毫秒
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用Iwao watanabe设计的培养基A,分离了水稻根际、根表和根内的固氮菌,并对其中75株好氧固氮菌进行了鉴定,发现水稻根区好氧固氮菌的数量随水稻生育期不同而变化,在水稻分蘖期,根际土壤中固氮菌数量最多,为2×10~7个细胞/克鲜土,根表为7×10~6个细胞/克鲜根,根内仅6.5×10~5个细胞/克鲜根,在抽穗扬花期则以根表为最多(2×10~9个细胞/克鲜根),根际为6×10~8个细胞/克鲜土,根内为6×10~7个细胞/克鲜根,水稻根系的好氧固氮菌,鉴定结果表明它们分属于八个属,其中肠杆菌科占25％,产碱菌属占24％,水稻根际以产碱菌属最多,克雷伯氏菌属为次,根表以芽孢菌属为主,其次为假单胞菌属,根内最多是固氮菌属,其次是芽孢杆菌属. 相似文献
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从豇豆煤霉病病区分离健株根际真菌菌株88个，优势菌群为青霉属和镰孢菌属，分别占84．7％和13．6％，病株根际分离菌株70个，优势菌群为青霉属和曲霉属,分别占74．2％和10％，键株根际分离出细菌菌株19株，其中杆菌17株，占89．5％，具荧光反应的9株，占47．4％；病株根际离出细菌菌株23株，其中杆菌16株，占68．2％。具荧光反应的6株，占26％，所分离的42个细菌菌株对青枯菌均无拮抗反应，对大白菜软腐病菌有拮抗作用的分别为5株和4株，分别占所测菌株的26．4％和17．4％，对瓜果腐霉病菌有拮抗作用的都为2株，分别占所测菌株的10．5％和8．7％。 相似文献
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不同农作物根际自生固氮菌分离及固氮酶活性 总被引：1，自引：0，他引：1
《江苏农业科学》2014,(7)
为了解高海拔地区农作物根际土壤自生固氮菌分布及优势菌株情况,以未施肥的油菜、玉米、青稞、小麦4种农作物种植点为采样地,对作物根际土壤自生固氮菌进行分离提纯,并根据其固氮酶活性筛选固氮能力较强的菌株。结果表明:油菜根际自生固氮菌数量较多,其固氮能力较其他3种作物更高,其中固氮性最好的菌株为德克斯氏菌属(Derxia spp.)菌株。 相似文献
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对不同类型的烟田土壤中细菌、固氮菌、放线菌及真菌进行分离,对不同微生物种群进行数量和多样性分析.结果表明,不同类型烟田土壤中,黄棕壤中细菌和固氮菌数量均高于紫色土.黄棕壤烟田土壤中细菌、固氮菌、放线菌及真菌变化速率分别高于紫色土中4种微生物变化速率;在黄棕壤烟田土壤中,细菌、固氮菌、放线菌及真菌变化速率呈现递减规律.黄棕壤中4种微生物根土比之和高于紫色土.黄棕壤中细菌与真菌数量的比值(B/F)几乎都高于紫色土.黄棕壤根际土中微生物菌群多样性指数与非根际土中微生物菌群多样性指数之比高于紫色土. 相似文献
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本文对桃树（Ｐｒｕｎｕｓ ｐｅｒｓｉｃａ Ｓｔｏｋｅｓ）、梨树（Ｐｙｒｕｓ ｓｐ．）根际线虫研究结果表明：桃树根际线虫中，寄生类占线虫总数量的９．３％，腐生类占５１．５％。捕食类占２４．８％，矛线类占１４．４％。梨树根际线虫中，寄生类８．８％，腐生类５１．６％，捕食类２２．６％，矛线类１８．０％。寄生类线虫，桃树根际线虫共鉴定出４个属，以螺旋线虫属（Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓ）为主；梨树根际共 相似文献
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[目的]研究不同比例的无芒雀麦与紫花苜蓿混播对青贮效果的影响。[方法]试验设5个处理,即紫花苜蓿单播、无芒雀麦单播、紫花苜蓿＋无芒雀麦以50％＋50％、60％＋40％和70％＋30％比例混播,分析各处理青贮材料的pH值、CP、NDF、ADF、乙酸、丁酸、乳酸和总酸的变化,研究无芒雀麦与紫花苜蓿不同比例混播对青贮品质的影响。[结果]与单播苜蓿相比,混播可以显著降低青材料的pH值（P〈0．01）、NH3．N／TN值（P〈0．01）和丁酸含量（P〈0．01）,有利于保存青贮物的营养成分。混播还可提高青贮产物中乙酸、乳酸和总酸的含量（P〈0．01）,从而提高苜蓿青贮品质。[结论]以混播处理A（苜蓿50％＋无芒雀麦50％）效果最好,pH值,NH3-N/TN的含量最低,乳酸含量和综合评分最高。 相似文献
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[目的]研究东乡普通野生稻（Oryza rufipogon Griff．）根际微生物群落特征。[方法]采用氯仿熏蒸浸提法测定根系微生物生物量碳、氮;采用平板稀释培养法测定群落组成;采用最大或然计数法测定微生物生理群。[结果]东乡野生稻根际微生物生物量碳、氮平均值分别为83．02和16．98mg／kg（土）,较普通栽培稻低;根际可培养微生物中细菌〉放线菌〉真菌;氮素生理群中氨化细茵〉好氧固氮菌〉反硝化细菌〉嫌气性固氮菌〉硝化细菌〉亚硝化细菌。[结论]东乡野生稻根际微生物群落组成与普通栽培稻相比有差异。 相似文献
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拮抗菌B501在草莓根际的定殖及对其他根际微生物的影响 总被引：7，自引：1，他引：7
对B501在草莓根际的定殖范围，群体数量的动态变化及对其他根际微生物种群与数量的影响进行了研究，结果表明，B501主要定殖于草莓根际与根表，B501的群体数量随草莓的生长呈动态变化，在根际，B501的数量水平以盛花期最高，在根表，数量水平呈渐增趋势，B501对草莓根际与根系可培养丝状真菌群体数量，对根系细菌总量的影响不显著，对根际细菌总量、根际与根系芽孢杆菌的数量有明显促进作用，连续两年的田间防效分别达到了93．9％和96．8％。 相似文献
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采用PKO培养基,从灵武长枣根际分离出135株有溶解磷能力的菌株,采用溶磷圈法测定其溶磷能力,其中有83株溶磷能力较强的菌株.分离到的菌株大多数在根际土壤中,少数来自根内,其中分离自根内的分离物有8个,占总数的9.6％.来自远离根的土壤即NRS有28个,占总数的33.8％左右,最多的是根际土壤RS,占总数的37.3％. 相似文献
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春小麦和苜蓿根际溶磷菌筛选及其溶磷能力测定 总被引：9，自引：2，他引：9
对春小麦(Triticum aestivum)和苜蓿(Medicago sativa)根际和非根际土壤中溶磷菌进行分离得到溶磷菌株368株,小麦和苜蓿根际溶磷菌数量分布为:根际土(RS)>远离根际土(NRS)>根表(RP)>根内(HP)。利用溶磷圈法初步筛选出66株具有较高溶磷能力的菌株,经钼蓝比色法测定其溶磷量,获得12株溶磷量大于100 mg/L的高效溶磷菌,且发现溶磷能力与pH值没有显著相关性。 相似文献
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《农业科学学报》2017,(1)
Fusarium sp.strain ZH-H2 is capable to degrade high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs),smooth bromegrass(Bromus inermis Leyss.) can also degrade 4- to 6-ring PAHs.Pot experiments were conducted to investigate how bromegrass and different inoculum sizes of ZH-H2 clean up HMW-PAHs in agricultural soil derived from a coal mine area.The results showed that,compared with control,different sizes of inocula of ZH-H2 effectively degraded HMW-PAHs,with removal rates of 19.01,34.25 and 29.26%for 4-,5- and 6-ring PAHs in the treatment with 1.0 g kg~(-1) ZHH2 incubation after 90 d.After 5 mon of cultivation,bromegrass reached degradation rate of these compounds by 12.66,36.26 and 36.24%,respectively.By adding strain ZH-H2 to bromegrass,HMW-PAHs degradation was further improved up to 4.24 times greater than bromegrass(W),in addition to the degradation rate of Bbf decrease.For removal rates of both 5- and 6-ring PAHs,addition of 0.5 g kg~(-1) Fusarium ZH-H2 to pots with bromegrass performed better than addition of0.1 g kg~(-1),while the highest concentration of 1.0 g kg~(-1) Fusahum ZH-H2 did not further improve degradation.Degradation of 4-ring PAHs showed no significant difference among different ZH-H2 incubations with bromegrass treatments.We found that the degradation rates of 4-,5- and 6-ring PAHs in all treatments are significantly correlated in a positive,linear manner with activity of lignin peroxidase(LiP)(r=0.8065,0.9350 and 0.9165,respectively),while degradation of 5- and 6-ring PAHs is correlated to polyphenoloxidase(PPO) activity(r=0.7577 and 07806).Our findings suggest that the combination of Fusahum sp.ZH-H2 and bromegrass offers a suitable alternative for phytoremediation of aged PAH-contaminated soil in coal mining areas,with a recommended inoculation size of 0.5 g Fusahum sp.ZH-H2 per kg soil. 相似文献
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用根尖压片法对青海栽培青稞染色体核型进行研究,旨在为今后青稞栽培品种的培育提供理论依据。结果表明：青海栽培青稞是二倍体,体细胞染色体数为2n=2x=14,染色体基数为x=7,紫青1号的核型公式是2n=2x=14=10m＋4smsat,昆仑164的核型公式是2n=2x=14=10m＋2smsat＋2msat。这两个品种核型类型都属于Stebbins-Ⅱ;北青3号的核型公式是2n=2x=14=12m＋2smsat,青稞1149的核型公式为2n=2x=14=10m＋2sm＋2msat,这两个品种核型类型都属于Stebbins-Ⅰ。 相似文献
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旨在研究外源铅(Pb)、砷(As)污染条件下对青稞生长品质以及铅砷富集等的影响,为农田土壤重金属复合污染防治以及改善人体饮食健康提供数据支撑。以青稞为供试作物,设置不同浓度Pb (480、720、960、1200、1440 mg/kg)、As (30、60、90、120、140 mg/kg)以及空白对照组（共计11个处理）,通过室外露天盆栽试验有针对性的检测外源铅砷胁迫下青稞生长和品质以及重金属的数据。外源铅、砷造成青稞根长、茎粗、株高、穗长、穗粒数、千粒重、地上及地下部干物质量与空白对照相比均降低了9.28%~66.58%。青稞的β-葡聚糖在铅浓度960 mg/kg时与空白相比下降了33.58%,水分与空白相比均低于空白;灰分、蛋白质与空白相比均高于空白;脂肪在铅浓度1440 mg/kg时与空白相比下降了54.16%,在铅浓度480 mg/kg条件下时与空白相比升高了13.75%。外源铅不同浓度处理下,青稞根、茎叶、籽粒中的铅含量均高于空白;外源砷不同浓度处理下,青稞根、茎叶、籽粒中的铅含量均高于空白。外源铅砷抑制了青稞生长、降低了青稞品质;青稞对铅的富集能力强于砷,且各器官铅、砷含量富集规律均为根>茎叶>籽粒。 相似文献
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XIE Kai-yun LI Xiang-lin HE Feng ZHANG Ying-jun WAN Li-qiang David B Hannaway WANG Dong QIN Yan Gamal M A Fadul 《农业科学学报》2015,14(9):1864-1876
Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa(Medicago sativa L.) grown alone and in mixture with smooth bromegrass(Bromus inermis Leyss.) in response to the addition of fertilizer N. Three levels of N(0, 75, and 150 kg ha–1) were examined using 15N-labeled urea to evaluate N2 fixation via the 15 N isotope dilution method. Treatments were designated N0(0.001 g per pot), N75(1.07 g per pot) and N150(2.14 g per pot). Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight(shoots+roots) was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa's N2 fixation was reduced with N fertilization(R2=0.9376, P=0.0057). When grown in a mixture with smooth bromegrass, with 75 kg ha–1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa(%Ndfa) had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grown alone(shoots: |t|=3.39, P=0.0096; root: |t|=3.57, P=0.0073). We believe this was due to smooth bromegrass being better able to absorb available soil N(due to its fibrous root system), resulting inlower soil N availability and allowing alfalfa to develop an effective N2 fixing symbiosis prior to the 1st harvest. Once soil N levels were depleted, alfalfa was able to fix N2, resulting in the majority of its tissue N being derived from biological nitrogen fixation(BNF) in the 2nd and 3rd harvests. When grown in a mixture, with added N, alfalfa established an effective symbiosis earlier than when grown alone; in monoculture BNF did not contribute a significant portion of plant N in the N75 and N150 treatments, whereas in the mixture, BNF contributed 17.90 and 16.28% for these treatments respectively. Alfalfa has a higher BNF efficiency when grown in a mixture, initiating BNF earlier, and having higher N2 fixation due to less inhibition by soil-available N. For the greatest N-use-efficiency and sustainable production, grass-legume mixtures are recommended for improving grasslands, using a moderate amount of N fertilizer(75 kg N ha–1) to provide optimum benefits. 相似文献
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[目的]比较海北地区青稞(Hordeum vulgare var.nudum)新品种(系)的产量性状、主要经济性状、生育期和抗逆性,筛选优良品种(系)。[方法]采用田间记载和室内分析相结合的方法,参试的11个品种(系)分别为33-2、95H1-29-9-1-6、95H1-49-7-6-3、03予115、95H1-49-7-8-7、2000-11-2、2000-23-21、2000-3、2000-24-42、2000-24-37、95H1-49-7-8-2,以北青六号(CK1)为主对照,北青四号(CK2)为辅对照,以上品种(系)均由海北州农业科学研究所选育。[结果]参试品种(系)中2000-24-37、2000-11-2在海北地区的适应性好,平均产量达到5 893和5 520 kg/hm2。尤其是品系2000-24-37株高最高,达到121 cm,而且抗倒伏性最强,符合国家大麦青稞产业技术体系所提出的粮草双高的育种目标。[结论]青稞新品系2000-24-37、2000-11-2综合表现较好,可以参加青海省青稞区域适应性试验,这为优良青稞新品种的选育奠定了基础。 相似文献
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本文利用5个不同青稞品种(品系)春播的试验资料,对其产量及产量构成因子进行主成分分析。结果表明,穗部因子的贡献率为48.44%、对产量影响最大,株高因子的贡献率为19.50%,公顷穗数因子的贡献率为10.54%,它们是影响产量的最主要因子。因此,在春播青稞高产育种性状选择时,应将穗部因子这一综合性状放在首要地位,同时控制株高在合理的范围,避免由于株高过高而导致青稞倒伏减产。本试验还表明,施用氮肥对青稞产量的构成因子有明显的促进作用。 相似文献