不同播期处理对玉米品种屯玉6号生长的影响

为了了解影响玉米高产的因素,研究了不同播期对屯玉6号生长的影响,将屯玉6号在6个不同播期下进行种植,分别测定其在各个不同生育时期的生长指标,并对这些指标进行分析比较。结果表明：适期早播能够增加株高和总叶数,有利于叶片干物质的积累,初步得出屯玉6号在当地的最适播期为4月17～22日。     

安徽省小麦孢囊线虫田间分布及危害调查

在田间用涕灭威作播前土壤处理抑制土壤中线虫虫口,测定分析田间小麦孢囊线虫对3个小麦品种分蘖期和孕穗期的生长影响。结果表明：小麦孢囊线虫田间分布模型为聚集分布,土壤中其卵密度范围为0～42．8粒／g土,平均密度为6．5粒／g土,已达到危害水平以上。小麦中前期生长调查表明,小麦孢囊线虫没有对分蘖期小麦生长造成显著影响;孕穗期小麦孢囊线虫的危害能造成小麦每株穗数减少13．8％、鲜重降低14．5％,但对株高没有影响;孕穗期小麦品种对孢囊线虫的反应差异显著,受小麦孢囊线虫危害后,新麦12和皖麦50的单株鲜重量分别降低23．3％和22．5％,孕穗数分别减少了25．9％和11．1％,但徐州8562孕穗数减少不显著。     

Lentil (Lens culinaris L.) growth promoting rhizobacteria and their effect on nodulation in coinoculation with rhizobia

Lentil is cultivated in Chilean Mediterranean drylands, in areas with soils that are nutrient depleted and eroded. Inoculation of lentil with rhizobia in co-inoculation with growth promoting rhizobacteria would allow higher biomass and an opportunity for early nodulation and increased nitrogen fixation. The objective of this research was to select rhizosferic bacteria (PGPR) from lentils and to evaluate their effect on lentil nodulation in co-inoculation with rhizobia. Sixty three lentil rhizobacteria isolates where obtained from nine soils in the mediterranean area. These were fingerprinted through BOX-PCR reducing the number to 57 distinct strains. The strains were evaluated for ACCdeaminase activity, IAA production and compatibility with rhizobia. Seventeen strains showed ACC-deaminase activity, all of them synthesized IAA and 38 were compatible with the rhizobia. Ten selected strains were identified as Pseudomonas spp. through 16S rRNA sequencing. The strains were inoculated in lentil seedlings growing on seed germination pouches, to evaluate nodule formation. The strain LY50a increased early nodulation in 85% in comparison to the control inoculated with rhizobia (AG-84) only. In conclusion, bacteria from the rhizosphere from Mediterranean soils of Chile can be used as nodulation promoters in lentils.     

丛枝菌根真菌和根瘤菌防控植物真菌病害的研究进展

丛枝菌根(arbuscular mycorrhiza,AM)真菌和根瘤菌均可在一定程度上减轻植物病害的发生,提高植物生物量。AM真菌提高寄主植物的抗病机理包括:改善寄主营养状况、补偿作用、改变根系形态、与病原菌竞争侵染位点和寄主光合作用产物、改变根际微生物区系以及激活寄主防御机制。根瘤菌防病机理可归纳为:寄主生理生化的变化、根系形态改变和寄主防御机制激活。AM真菌和根瘤菌两者相互作用,可更好地防控植物病害。本文归纳了国内外AM真菌和根瘤菌对植物抗病性的影响及机理,同时展望了两者在生防中的应用前景。     

黑土区紫花苜蓿根瘤菌特性研究与促生能力分析

本文通过采集东北黑土地区2龄紫花苜蓿(Medicago)根瘤菌菌株,经过根瘤菌的耐盐、耐碱、耐酸、溶磷能力、生长素分泌能力、代时、固氮酶活性等生物学特性测试;并进行回接试验,测定供试菌株促生植株的根瘤数、根瘤重、生物量及全氮量,旨在阐明黑土区苜蓿根瘤菌特性与促生植株地上生物量及其全氮的关系。结果表明:菌株促生植株的全氮量与根瘤菌泌酸能力、代时、促生植株根瘤数显著相关(P≤0.05);菌株促生植株地上生物量与菌株溶磷能力、泌酸能力、促生植株根瘤重呈极显著相关(P≤0.01)。通过通径分和回归分析建立了苜蓿根瘤菌株促生植株地上生物量及其全氮量的最优多元线性回归方程,该方程可为优异菌株筛选及其促生能力判断提供科学依据。     

烟丝含水率对卷烟落锥及烟气成分的影响

[目的]了解烟丝含水率对卷烟落锥及烟气成分的影响。[方法]研究了部分贵烟牌号在不同平衡湿度条件下的卷烟落锥及烟气成分情况。[结果]卷烟烟丝含水率随平衡湿度增加而逐渐增加,卷烟的总粒相物、烟气烟碱、焦油含量变化不明显,卷烟抽吸口数、一氧化碳量呈现出相同的增加趋势,当烟丝水分条件一定,各烟气成分间并无显著的关联性;卷烟含水率升高,卷烟落锥数量明显减少,不同含水率条件对卷烟落锥的影响要大于不同卷烟之间造成的影响,不同卷烟之间的落锥个数存在显著差异,卷烟在50%与60%水分条件下落锥个数无明显差异,其余含水率条件下卷烟的落锥个数存在显著差异。[结论]不同烟丝含水率及烟丝结构对卷烟落锥量有明显影响。     

黄土高原地区优良大豆根瘤菌的筛选与接种方式研究

采用蛭石和土壤盆栽试验,从黄土高原地区17个大豆品种上采集根瘤,对根瘤进行分离纯化、回接验证和遗传多样性分析,根据遗传多样性分析结果、分离宿主和分离地点,选出代表菌株用于筛选与黄土高原地区面积种植最大的大豆品种晋豆25相匹配的优良菌株,并在田间进行了根瘤菌喷施、拌种和种下接种不同接种方式效果比较试验.以瘤数、瘤干重、植株干重、植株全氮量为指标,通过蛭石盆栽试验初筛获得与晋豆25共生匹配效果好的根瘤菌10株;其进一步的耐旱试验和土壤盆栽复筛结果表明:菌株Bradyrhizobium liaoningense 4345和Sinorhizobium fredii 4338在结瘤能力、固氮能力、竞争能力和耐旱性能方面最好,揭示B. liaoningense 4345和S. fredii 4338具有良好应用前景.在田间进行的根瘤菌3种接种方式小区试验中,B. liaoningense 4345喷施处理在大豆植株干重、植株全氮量、占瘤率和产量等方面均显著高于另2个处理和对照,S. fredii 4338拌种和喷施较好,表明黄土高原地区大豆根瘤菌的适宜接种方式是喷施和拌种.     

Parasitic plant infection is partially controlled through symbiotic pathways

Legumes are unique in interacting with Rhizobium , arbuscular mycorrhizal (AM) fungi, and parasitic plants. To dissect common parts of these three plant–organism interactions, infection by Orobanche crenata was studied in mutants with altered symbiotic phenotypes of Medicago truncatula and Pisum sativum . Orobanche crenata inoculation of mutant lines carrying defective mutation in the genes dmi2 / sym19 and dmi3 resulted in an increase in O. crenata establishment. Similarly, inoculation of mutants carrying mutation in the gene sunn / sym29 that controls the autoregulation mechanism of the symbiosis, also lead to a significant increase in haustoria formation. Altogether, our results suggest that parasitic plant infection is partly controlled by both the conserved symbiotic pathway that mediates symbiont recognition and establishment and the autoregulation mechanism that regulates the extent of colonisation by Rhizobium and AM fungi.     

根瘤菌的RAPD分子标记技术检测和耐盐碱筛选

采用17株分离于苜蓿和草木樨的根瘤菌为研究对象,进行了RAPD分子标记技术检测和耐盐碱筛选实验。结果显示:供试根瘤菌菌体基因组RAPD电泳图谱分为6组不同的条带,说明17株菌中有6个不同菌系。不同菌系的根瘤菌耐盐碱筛选试验表明,来自临泽的根瘤菌耐盐碱能力均比来自天水的强,其中两株能在pH14的YMA培养基上生长,一株可耐1.539 mol/L的NaCl,两株能耐1.971 mol/L的Na2SO4,尤其菌GL007对高pH和两种盐都有较强的忍耐性,是实验筛选出的珍贵耐盐碱菌种资源。     

根瘤菌菌株和接种根瘤菌植株的耐旱性研究进展

干热地区适生豆科树种及其特有的固氮根瘤菌为该地区生态植被恢复和农业生产能力提高提供了新的方法和发展思路。在干热地区能筛选出耐干热的根瘤菌菌株和接种根瘤菌植株,接种耐干热的根瘤菌能提高寄主豆科植物的耐干热能力,但其机理国内外鲜有研究。