基于16S rDNA基因高通量测序分析农田栽参土壤改良后的细菌群落结构

为揭示农田栽参土壤改良中几种常用肥料施用后对土壤细菌群落的影响。利用Illumina Miseq高通量测序技术,分析测定肥料施用后土壤中细菌群落结构、物种丰度及物种组成。通过相关性分析研究土壤细菌群落多样性与土壤元素及土壤酶活性的关系。结果表明,施用肥料后鞘氨醇单胞菌属(Sphingomonas)、罗思河小杆菌属(Rhodanobacter)、norank_o_Saccharimonadales、节杆菌属(Arthrobacter)、norank_o_Gaiellales等菌属为土壤中优势菌属;F中细菌群落多样性最高,即ace指数与chao1指数最高。处理C细菌群落丰度最高,F处理细菌群落丰度最低;相关性分析发现土壤酶活性、土壤元素与土壤细菌群落结构存在显著相关性,UE、OM、p H、K、Fe、N、Ca等环境因子对土壤细菌结构影响较大。说明除了直接施入菌剂改变土壤细菌群落结构,通过改变土壤性质,也可以间接改变土壤细菌群落结构。研究表明,几种肥料的施用可以改善土壤细菌群落结构,其中,C肥料可以显著提高细菌群落丰度;A处理显著提高有益菌属鞘氨醇单胞菌属(Sphingomonas)的丰度;E处理使拮抗菌属罗思河小杆菌属(Rhodanobacter)丰度增加。本研究为几种常用肥料对土壤改良后土壤细菌种类、群落结构及其功能的影响机制提供实验依据。     

水肥耦合对科尔沁羊草割草场植物群落多样性和生产力的影响

采用随机区组设计,探讨了不同时间及水肥耦合用量对科尔沁羊草(Leymus chinensis)割草场植物群落特征、草地生产力和物种多样性的影响。结果表明:在5月30日和6月15日时,加水量15 mm加尿素150 kg/hm~2(15N)的水肥耦合组合群落高度、盖度、密度和地上生物量较对照显著增加,其中,地上生物量是对照的2倍多;水肥耦合降低了物种多样性指数,5月15日的15N处理使得群落Margalef丰富度指数、Shannon-wiener多样性指数和Simpson指数显著降低(P0.05)。在科尔沁沙质羊草割草场进行草地改良,最佳的实施时间应该在5月30日以后,15N可作为优先水肥耦合组合来推荐。     

长期不同施肥对农田土壤养分与微生物群落结构的影响

为了阐明长期不同施肥对土壤养分与微生物群落的影响及影响机理,以杭嘉湖平原典型稻麦轮作区长期定位施肥试验土壤为对象,采用磷脂脂肪酸(Phospholipid fatty acid, PLFA)分析方法,研究了施用化肥(NPK)、秸秆(Straw)、栏肥(Manure)、化肥与秸秆配施(S+NPK)、化肥与栏肥配施(M+NPK)5种不同施肥方式对土壤主要养分指标与微生物量及微生物群落结构的影响,试验以不施肥处理为对照。结果表明,所有施肥处理均提高了土壤有机碳,其中秸秆与化肥配施、栏肥无论是单独施用还是与化肥配施所提高的有机碳含量均达到显著水平;施用化肥、有机肥、秸秆+化肥及有机肥+化肥均可在一定程度增加土壤氮、磷、钾养分。施用秸秆和栏肥显著提高了土壤中总PLFA、细菌、真菌、放线菌等含量以及微生物群落Shannon指数(P＜0.05),但施用化肥可引起土壤微生物量和多样性指数的下降。相关分析结果表明,土壤微生物PLFA含量及Shannon指数与土壤碳氮比呈显著正相关(P＜0.05)。典范对应分析结果表明,土壤有机碳含量(F=2.18,P=0.027)是影响微生物群落结构的主要环境因子。可得出结论,长期秸秆还田或施用栏肥可显著提高土壤微生物量并改变其群落结构,土壤有机碳含量及碳氮比对于土壤质量和肥力的提高具有至关重要的作用。     

不同提取工艺制备的海藻肥在盆栽小油菜上的肥效研究

为对比不同提取工艺制备的海藻肥在小油菜上的肥效,通过设置盆栽试验,对酸提海藻液、酸-碱提海藻液、史丹利酶提海藻液、史丹利微生物提海藻液在小油菜上的施用效果进行研究。结果表明：史丹利酶提海藻液、微生物提海藻液反应条件温和、易于制备,产品外观细腻稳定,海藻酸、赤霉素、吲哚乙酸等有效物质含量高,从工艺和产品品质方面优于酸提海藻液和酸-碱提海藻液;施用史丹利微生物提海藻液处理的油菜株高、叶绿素值均显著高于其他处理,其中株高和叶绿素值分别比酸-碱提海藻液处理高13.3%和22.5%、比酸提海藻液处理高23.5%和26.9%;施用微生物提、酶提海藻液处理的小油菜间地上植株鲜重与干重均无显著差异,均显著高于其他处理,其中微生物提海藻液处理鲜重分别比酸-碱提海藻液和酸提海藻液处理高12.6%和15.8%。研究表明,4 种提取工艺制备的海藻肥的肥效为：酸提海藻液＜酸-碱提海藻液＜史丹利酶提海藻液＜史丹利微生物提海藻液。     

草木灰对烤烟根际土壤微生物群落结构及代谢功能多样性的影响

施用草木灰旨在改善土壤微生物群落结构，减少由土壤自身衰退而引发的土传病害，更好的维持土壤生态系统的平衡。通过田间小区试验，采用平板培养法和BIOLOG技术研究施用草木灰对烤烟根际土壤微生物数量和功能多样性的影响。研究结果表明：施用草木灰显著增加了烤烟根际细菌、放线菌和微生物总量(P＜0.05)，真菌数量虽略有降低但差异并不明显；移栽后35、55、75天的3个时间段均有一致规律。同时，上述3个时间段烤烟根际微生物群落碳源利用率(AWCD)和对6类碳源的利用程度也以施用草木灰处理显著高于对照。施用草木灰后，烟株各时期根际土壤微生物群落Shannon 指数(H)、Simpson指数(D)、均匀度指数(E)、丰富度指数(S)(P＜0.05)均有所提高，其中移栽后35天时差异显著。根际微生物群落的PCA分析表明，增施草木灰处理和对照在主成分坐标体系中差异十分明显，草木灰处理集中在第1主成分正方向，而未施用的对照则集中在第1主成分负方向，表明土壤微生物功能多样性差异显著。上述说明增施草木灰在改善烟株根际土壤微生物群落结构及功能多样性方面有明显效果。     

草木灰对烤烟根际土壤微生物群落结构及功能多样性的影响

施用草木灰旨在改善土壤微生物群落结构,减少由土壤自身衰退而引发的土传病害,更好的维持土壤生态系统的平衡。通过田间小区试验,采用平板培养法和BIOLOG技术研究施用草木灰对烤烟根际土壤微生物数量和功能多样性的影响。研究结果表明:施用草木灰显著增加了烤烟根际细菌、放线菌和微生物总量(P0.05),真菌数量虽略有降低但差异并不明显;移栽后35、55、75天的3个时间段均有一致规律。同时,上述3个时间段烤烟根际微生物群落碳源利用率(AWCD)和对6类碳源的利用程度也以施用草木灰处理显著高于对照。施用草木灰后,烟株各时期根际土壤微生物群落Shannon指数(H)、Simpson指数(D)、均匀度指数(E)、丰富度指数(S)(P0.05)均有所提高,其中移栽后35天时差异显著。根际微生物群落的PCA分析表明,增施草木灰处理和对照在主成分坐标体系中差异十分明显,草木灰处理集中在第1主成分正方向,而未施用的对照则集中在第1主成分负方向,表明土壤微生物功能多样性差异显著。上述说明增施草木灰在改善烟株根际土壤微生物群落结构及功能多样性方面有明显效果。     

临沭县冬小麦复合微生物肥效对比试验

为了讨论复合微生物肥料在冬小麦上的肥料效应,开展同等地力条件下,冬小麦使用复合微生物肥料(含有机质)和测土配方研制的小麦专用配方肥(大量元素肥料)对比试验。试验表明:施用复合微生物肥料(含有机质),对改善冬小麦的农艺性状、增产增效等均有良好的效果。     

久佳复合微生物肥料对杂交水稻产量和性状的影响

为探讨久佳复合微生物肥料施用量与水稻产量和性状的关系,以杂交水稻品种宜香优2886为试材,采用田间试验研究了不同栽培方式(移栽、直播)和久佳复合微生物肥料不同施用量对产量和性状的影响。结果表明:施用久佳复合微生物肥料比不施的处理增产4.0%~9.64%。移栽方式施用久佳复合微生物肥料3kg/667m2处理的产量最高,为606.97kg/667m2,比移栽方式施用久佳复合微生物肥料的处理增产2.25%~4.6%,比移栽方式不施久佳复合微生物肥料处理增产9.64%。移栽方式施用久佳复合微生物肥料3kg/667m2处理的性状较好,每穗总粒数162.27粒、每穗实粒数143.31粒、结实率88.32%,分别比移栽方式不施久佳复合微生物肥料的处理增加2.56粒、8.49粒和3.9个百分点。久佳复合微生物肥料对株高、穗长和千粒重的影响较小。     

褐煤腐殖酸对旱作燕麦土壤微生物量碳、氮、磷含量及土壤酶活性的影响

以燕麦坝莜一号为试验材料,设置不施褐煤腐殖酸常规处理(CK),仅2011年施用腐殖酸,连续2年、连续3年、连续4年施用腐殖酸,以研究腐殖酸对土壤微生物量及酶活性的影响,从而明确腐殖酸对土壤生物学性状的改善效果。试验结果表明,连续多年施用腐殖酸可增加燕麦苗期土壤微生物生物量碳、氮、磷含量,增强土壤蔗糖酶、脲酶、过氧化氢酶活性,有利于培肥土壤,促进土壤中有机物质的分解和转化以及土壤碳、氮等养分的循环,达到提高土壤质量的目的。不同施用年限腐殖酸对土壤酶活性及微生物量的影响不同,连续施用腐殖酸4年的作用优于连续施用3年、2年、1年,4种处理均优于CK处理,说明土壤腐殖酸的累积效应对土壤微生态环境的改善起到积极的作用,其中多年施用腐殖酸对改善10~20cm土壤脲酶活性、微生物生物量氮含量作用显著,能为作物根系生长提供充足的氮素。试验发现土壤酶活性与土壤微生物量之间具有很好的相关性,土壤酶活性可以作为评价土壤微生物量高低的指标。     

褐煤腐殖酸对旱作燕麦上壤微生物量碳、氮、磷含量及土壤酶活性的影响

以燕麦坝筱一号为试验材料,设置不施揭煤腐殖酸常规处理(CK),仅2011年施用腐殖酸,连续2年、连续3年、连续4年施用腐殖酸,以研究腐殖酸对土壤微生物量及酶活性的影响,从而明确腐殖酸对土壤生物学性状的改善效果。试验结果表明,连续多年施用腐殖酸可增加燕麦苗期土壤微生物生物量碳、氮、磷含量,增强土壤蔗糖酶、服酶、过氧化氢酶活性,有利于培肥土壤,促进土壤中有机物质的分解和转化以及土壤碳、氮等养分的循环,达到提高土壤质量的目的。不同施用年限腐殖酸对土壤酶活性及微生物量的影响不同,连续施用腐殖酸4年的作用优于连续施用3年、2年、1年,4种处理均优于CK处理,说明土壤腐殖酸的累积效应对土壤微生态环境的改善起到积极的作用,其中多年施用腐殖酸对改善10~20cm土壤脉酶活性、微生物生物量氮含量作用显著,能为作物根系生长提供充足的氮素。试验发现土壤酶活性与土壤微生物量之间具有很好的相关性,土壤酶活性可以作为评价土壤微生物量高低的指标。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.