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1.
为探讨纳米杀菌剂对小麦根腐病害的防控效果,以小麦京东8号为供试材料,通过盆栽试验,探究土壤接种麦根腐平脐孺孢(Bipolaris sorokiniana)情况下,自制纳米ZnO-Ag复合材料对B.sorokiniana的抑菌效果和小麦幼苗生长的影响。结果表明,纳米ZnO-Ag复合材料能显著抑制小麦根腐菌菌丝的生长,抑制作用随ZnO-Ag浓度的增加而增强;200 μg·mL-1ZnO-Ag对病菌菌丝的抑制率高达91.17%,有效中浓度(EC50)为34.15 μg·mL-1;在土壤接菌情况下,经大于12.5 μg·g-1ZnO-Ag复合材料处理,小麦种子的发芽势和发芽率、幼苗的根长、株高、地上部鲜重和干重、地下部鲜重和干重均显著高于对照组(未加纳米材料),小麦幼苗发病率显著低于对照组;浓度大于12.5 μg·g-1ZnO-Ag处理组的小麦幼苗根长/株高和根冠比显著低于对照组。由此可得,纳米ZnO-Ag复合材料能够有效抑制土壤中小麦根腐病菌的生长,促进小麦种子萌发和幼苗生长,降低幼苗发病率。此结果为ZnO-Ag防控小麦根腐害提供了理论依据。  相似文献   

2.
为明确异源染色体的附加对普通小麦氮、磷吸收能力和利用效率的影响,以中国春为对照,设计不同浓度水平的氮、磷组合进行苗期水培试验,评价了43份中国春背景下小麦异附加系的氮、磷吸收能力和利用效率。对不同水平氮磷组合处理下的苗期表型调查发现,氮、磷胁迫均会抑制地上部分生长,促进地下部分生长;低氮胁迫降低了苗期的株高、茎干重和总干重,提高了根长、叶数、SPAD值及根茎比;磷缺乏提高了根干重和根茎比,抑制了其余性状。在中氮和低氮处理下,Ae.searsii 1SS等13个小麦异附加系的总干重高于中国春,表现出稳定的氮高效;低氮处理下,Ps.huashanica E等9个小麦异附加系的氮吸收能力显著高于中国春,Ps.huashanica C等4个小麦异附加系的氮利用效率显著高于中国春。在磷充足及磷胁迫处理下,Ag.intermedium B等5个小麦异附加系的总干重高于中国春,表现出稳定的磷高效;低磷处理下,Ag.intermedium B等4个小麦异附加系的磷吸收能力显著高于中国春,L.racemosus L附加系和Ag.elongatum 6E附加系的磷利用效率显著高于中国春。进一步分析氮、磷高效的小麦异附加系携带的异源染色体,没有观察到染色体部分同源群聚集的现象。筛选出的异源染色体附加系可作为小麦育种的中间材料,进行养分高效的遗传分析或育种应用。  相似文献   

3.
株行距配置对玉米根系性状及产量的影响   总被引:5,自引:1,他引:4  
以郑单958为材料, 采用田间试验方法, 在50 025株/hm2、67 500株/hm2、100 050株/hm2密度下分别设两种株行距配置, 探讨增密条件下调控株行距配置对玉米根系性状及产量影响。结果表明, 3个种植密度下总体表现为小行距种植方式在0~60 cm土层内的根重密度、根长密度及根表面积密度均高于大行距处理。50 025株/hm2下吐丝期时0~60 cm土层内的根重密度和根长密度在两个株行距配置间差异显著(P<0.05), 两个株行距配置的根表面积密度在10叶展、吐丝期和吐丝后25 d差异显著(P<0.05);67 500株/hm2下不同时期两个株行距配置根重密度差异显著(P<0.05), 根长密度和根表面积密度在10叶展和吐丝后25 d差异显著(P<0.05);100 050株/hm2下, 两个株行距配置间根重密度和根长密度在10叶展和吐丝后25 d差异显著(P<0.05), 不同时期根表面积密度差异显著(P< 0.05)。同一密度下缩行增株后单株木质部伤流液体积增大, 根系供应能力增强, 产量增加, 50 025株/hm2、67 500株/hm2下产量分别提高了6.76%和4.89%。不同时期0~60 cm土层内根重密度、根长密度和根表面积密度与产量呈正相关, 其中10叶展时各根系性状均与产量呈显著正相关。  相似文献   

4.
为总结施氮量与小麦根系生长及产量的关系,通过查询近30年(1993-2019年)中国主要麦区施氮量对小麦根长密度、根干重密度及产量影响的文献资料,对小麦适宜的施氮范围进行分析。结果表明,随着土层的加深,小麦根长密度(RLD) 和根干重密度(RDWD)总体上呈逐渐降低的趋势,且小麦根系主要分布在0~20 cm土层。不同施氮量下0~60 cm土层小麦开花期的RLD 和RDWD均高于成熟期,开花期的RLD 和RDWD分别在施氮220~235和192~209 kg·hm-2时达到最大值,成熟期分别在施氮220~275和 171~212 kg·hm-2达到最大值。经相关性分析,小麦产量与RLD、RDWD均呈显著正相关。通过对施氮量与小麦籽粒产量进行一元二次方程拟合得出,在施氮量为247 kg·hm-2时小麦产量达到峰值。因此,在当前中国主要麦区向农户推荐氮肥用量时,需针对不同区域,结合农田实际,在施氮171~247 kg·hm-2范围选择合理用量,以促进小麦根系的生长发育及籽粒产量的提高。  相似文献   

5.
为了解不同小麦种质萌发期抗旱性强弱,以20% PEG6000溶液模拟干旱胁迫,对119份春小麦萌发期种子发芽势、种子发芽率、根鲜重、根干重、苗鲜重、苗干重、叶鲜重、叶干重、根长和苗长进行测定分析,并综合评价其抗旱性。结果表明,种子发芽势、种子发芽率、苗鲜重、苗干重、叶鲜重和苗长可以作为评价春小麦萌发期抗旱能力的主要指标,并筛选出了1份抗旱型材料、36份较抗旱型材料、43份较敏感型材料和39份敏感型材料。为进一步研究抗旱相关基因在抗旱型与干旱敏感型材料萌发期响应干旱胁迫的表达特性,从而验证抗旱材料鉴定的准确性,以筛选出的2份抗旱性最好的种质(蒙茬1号、黑穗)和2份干旱敏感型种质(09594、K250)为材料,利用qRT-PCR对其在不同时长(0 h、1 h、6 h、12 h、24 h)的20% PEG6000胁迫下 TaNAC29TaC2DP1TaDLEA3 TaCP Taα-AMY TaGPX 的表达特性进行分析表明,随着胁迫时间的增加,以上6种基因在小麦叶片和根系中均上调表达,表达量均在胁迫24 h时达到峰值,且 TaNAC29 TaDLEA3 TaCP TaGPX 在根系中的表达量均明显高于叶片,而 TaC2DP1 Taα-AMY 在叶片中的表达量更高;此外,抗旱材料蒙茬1号和黑穗中6种基因的表达量均高于敏感材料09594和K250。  相似文献   

6.
为了明确在河南不同生产条件下实现小麦高产高效的耕作技术,通过CNKI和Web of Science进行文献检索,共获得45篇相关大田文献和192组试验数据,以常规耕作(翻耕)为对照,采用Meta分析方法,定量分析了不同区域、不同降雨量、不同施氮量、不同土壤类型下旋耕、深松耕、免耕对河南小麦产量及水分利用效率的影响。结果表明,与常规耕作相比,旋耕小麦的产量和水分利用效率分别降低3.08% (P<0.05)和3.75%(P>0.05),深松耕提高10.46%(P<0.05)和8.56%(P<0.05),免耕提高2.32% (P>0.05)和8.32%(P<0.05)。其中,旋耕小麦产量在豫东、豫南、豫北均显著降低,降幅分别为10.58%、7.85%、 4.05%;深松耕小麦产量在豫中、豫东、豫西均显著提高,增幅分别为12.58%、15.01%、12.29%;免耕小麦产量在豫西和豫南分别显著增加(增幅8.38%)和显著降低(降幅4.15%)。与常规耕作相比,在年降雨量≤500 mm、500~600 mm、>600 mm下,旋耕小麦产量均显著降低,降幅分别为6.30%、4.20%、 3.33%,水分利用效率均无显著变化;深松耕产量均显著提高,增幅分别为13.68%、7.19%、11.45%,水分利用效率分别提高9.23%(P<0.05)、6.45%(P>0.05)、16.79%(P<0.05);免耕小麦产量在年降雨量500~600 mm条件下提高6.23%(P<0.05),水分利用效率在年降雨量>600 mm条件下提高10.87% (P<0.05)。与常规耕作相比,旋耕小麦产量和水分利用效率在施氮量150~240 kg·hm-2条件下均显著降低,降幅分别为5.39%和 7.54%;深松耕小麦产量在施氮量≤150 kg·hm-2和150~240 kg·hm-2条件下,水分利用效率在施氮量≤150 kg·hm-2、150~240 kg·hm-2、>240 kg·hm-2条件下均显著提高,产量增幅分别为12.41%和 9.65%,水分利用效率增幅分别为8.98%、11.69%和11.21%;免耕小麦的产量和水分利用效率在施氮量≤150 kg·hm-2条件下分别提高8.88%和11.10%。与常规耕作相比,在潮土和砂姜黑土条件下旋耕小麦产量均显著降低,降幅分别为9.48%和9.25%,而在黄土条件下免耕小麦产量和水分利用效率均显著提高,增幅分别为8.38%和9.21%;深松耕在不同土壤类型下均能提高小麦产量和水分用效率,且在壤土和黄土条件下效果较好。综上,旋耕在河南不同生产条件下均会降低小麦产量和水分利用效率;除豫南外,深松耕均可提高河南小麦产量和水分利用效率;免耕显著提高了总体水分利用效率,尤其在豫西地区、施氮量≤150 kg·hm-2以及黄土质地条件下效果显著。因此,采用深松耕技术有利于提高河南除豫南外地区的小麦产量和水分利用效率,在豫西地区、施氮量≤150 kg·hm-2或黄土条件下也可以应用免耕技术。  相似文献   

7.
研究缺氮对玉米自交系B73组蛋白修饰酶的影响,分析组蛋白修饰如何对玉米发育过程中土壤氮浓度的波动进行微调适应不同的氮浓度环境提供一定的理论依据。结果表明,吐丝后1~2周,缺氮雌穗的穗长和干重分别降低16.2%~19.7%和35.6%~44.4%,氮浓度在吐丝后第二周降低13.3%。利用qRT-PCR技术,对玉米苗期以及雌穗形成关键时期的组蛋白乙酰化酶(GCN5和HAT-B)和去乙酰化酶基因(HD1bHD2HDA101HDA102HDA106HDA108)的表达进行分析,苗期缺氮8 d,除HAT-B基因外,其余7个基因的表达水平均急剧上升;缺氮36 h,HAT-B、HDA101、HD1bHD2基因的表达量增加;缺氮处理2 d,基因HDA106HDA108的表达水平下调。吐丝期雌穗,除HAT-B、HD1bHD2基因外,其余5个基因都有较高的表达水平;在吐丝期前1周,缺氮导致HDA101HDA106基因的表达水平均显著上调;基因HD1bHD2在吐丝期后第二周表达水平则明显下调。缺氮胁迫使ZmHATs和ZmHDACs的表达可能存在协同性、功能分化性、时空摆动性以及通过不同途径调控植物对缺氮胁迫的响应等特征,说明ZmHATs和ZmHDACs在玉米缺氮胁迫适应中发挥着重要作用。  相似文献   

8.
施氮量对利民33光合特性及产量的影响   总被引:3,自引:1,他引:2  
在大田试验条件下设氮肥用量分别为N0(不施氮肥)、施氮120(N120)、200(N200)、280(N280)和360 kg/hm2(N360)5个处理,测定叶面积和叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率(Tr)和产量,探讨不同施氮量对利民33光合特性及产量的影响。研究结果表明,随施氮量的增加,利民33叶面积指数、叶绿素含量、净光合速率、光能利用率提高,进而提高产量;产量与净光合速率、气孔导度、蒸腾速率和光能利用率呈正相关,与胞间二氧化碳浓度呈负相关;产量与施氮量的回归方程为Y=-0.05x2+32.38x+6 351(R2=0.98),最高产量施氮量为335.9 kg/hm2。  相似文献   

9.
为了建立准确有效小麦HMW-GS的检测方法,提高优质小麦品种鉴定和筛选效率,以已知HMW-GS组成的16份小麦品种为对照,优化完善SDS-PAGE结合分子标记检测小麦HMW-GS的方法,并对103份宁夏小麦品种进行了验证和分析。结果表明,8.5%的分离胶可以有效区分除了 Glu-B1位点的7*、7OE与8*亚基之外的其他亚基,分辨效果优良;SDS-PAGE结合 Bx7OEBx7*/Bx7By8基因的分子标记可以准确鉴定小麦HMW-GS。在103份宁夏小麦品种中,发现15种HMW-GS和29种组合类型;首次在该地区小麦品种的 Glu-B1位点检测出了携带7OE、7*和8*亚基的品种;1/17+18/5+10为当地小麦HMW-GS的优势亚基组合类型,占20%。自1970年至2010年,HMW-GS的优质亚基(1、17+18和5+10)的出现频率呈明显增长趋势;宁夏小麦的HMW-GS种类和优质亚基出现频率随品种更换呈增加趋势。综上所述,分离胶浓度为8.5% 的SDS-PAGE和 Bx7OEBx7*/Bx7By8分子标记的方法可准确有效地检测小麦HMW-GS组成,此方法可用于优质小麦品种的鉴定和筛选。  相似文献   

10.
施氮对高淀粉玉米子粒产量形成的影响   总被引:1,自引:0,他引:1  
采用田间试验、植株生理生化分析方法,研究了不同施氮量对高淀粉玉米吉单535和普通玉米军单8号子粒产量形成的影响。结果表明,高淀粉玉米粒重的增长符合Logistic方程;营养体干重随时间的变化符合回归方程Y=axebx;生物产量依子粒产量和营养体干重变化符合回归方程Y=exp(a+b1x1+b2x2)。与普通玉米军单8号比较,高淀粉玉米吉单535营养体干重增长期较长,干重下降速率低,即由营养体干物质向子粒转运量较低。适宜的施氮量可有效地促进高淀粉玉米植株生育前期总生物量的积累以及生育后期干物质从营养体向子粒的转移,从而获得较高产量。高淀粉玉米吉单535的适宜施氮量为200 kg/hm2。  相似文献   

11.
Cyanobacteria are a rich source of secondary metabolites with a vast biotechnological potential. These compounds have intrigued the scientific community due their uniqueness and diversity, which is guaranteed by a rich enzymatic apparatus. The ribosomally synthesized and post-translationally modified peptides (RiPPs) are among the most promising metabolite groups derived from cyanobacteria. They are interested in numerous biological and ecological processes, many of which are entirely unknown. Microviridins are among the most recognized class of ribosomal peptides formed by cyanobacteria. These oligopeptides are potent inhibitors of protease; thus, they can be used for drug development and the control of mosquitoes. They also play a key ecological role in the defense of cyanobacteria against microcrustaceans. The purpose of this review is to systematically identify the key characteristics of microviridins, including its chemical structure and biosynthesis, as well as its biotechnological and ecological significance.  相似文献   

12.
Aeruginosamides (AEGs) are classified as cyanobactins, ribosomally synthesized peptides with post-translational modifications. They have been identified in cyanobacteria of genera Microcystis, Oscillatoria, and Limnoraphis. In this work, the new data on the in vitro activities of three AEG variants, AEG A, AEG625 and AEG657, and their interactions with metabolic enzymes are reported. Two aeruginosamides, AEG625 and AEG657, decreased the viability of human breast cancer cell line T47D, but neither of the peptides was active against human liver cancer cell line Huh7. AEGs also did not change the expression of MIR92b-3p, but for AEG625, the induction of oxidative stress was observed. In the presence of a liver S9 fraction containing microsomal and cytosolic enzymes, AEG625 and AEG657 showed high stability. In the same assays, quick removal of AEG A was recorded. The peptides had mild activity against three cytochrome P450 enzymes, CYP2C9, CYP2D6 and CYP3A4, but only at the highest concentration used in the study (60 µM). The properties of AEGs, i.e., cytotoxic activity and in vitro interactions with important metabolic enzymes, form a good basis for further studies on their pharmacological potential.  相似文献   

13.
Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.  相似文献   

14.
Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.  相似文献   

15.
The blood coagulation cascade involves the human coagulation factors thrombin and an activated factor VII (fVIIa). Thrombin and fVIIa are vitamin-K-dependent clotting factors associated with bleeding, bleeding complications and disorders. Thrombin and fVIIa cause excessive bleeding when treated with vitamin-K antagonists. In this research, we explored different strains of toxic Microcystis aeruginosa and cyanobacteria blooms for the probable fVIIa-soluble Tissue Factor (fVIIa-sTF) inhibitors. The algal cells were subjected to acidification, and reverse phase (ODS) chromatography-solid phase extraction eluted by water to 100% MeOH with 20%-MeOH increments except for M. aeruginosa NIES-89, from the National Institute for Environmental Studies (NIES), which was eluted with 5%-MeOH increments as an isolation procedure to separate aeruginosins 89A and B from co-eluting microcystins. The 40%–80% MeOH fractions of the cyanobacterial extract are active against fVIIa-sTF. The fVIIa-sTF active fractions from cultured cyanobacteria and cyanobacteria blooms were subjected to liquid chromatography-mass spectrometry (LC-MS). The 60% MeOH fraction of M. aeruginosa K139 exhibited an m/z 603 [M + H]+ attributed to aeruginosin K139, and the 40% MeOH fraction of M. aeruginosa NIES-89 displayed ions with m/z 617 [M − SO3 + H]+ and m/z [M + H]+ 717, which attributed to aeruginosin 89. Aeruginosins 102A/B and 298A/B were also observed from other toxic strains of M. aeruginosa with positive fVIIa-sTF inhibitory activity. The active fractions contained cyanobacterial peptides of the aeruginosin class as fVIIa-sTF inhibitors detected by LC-MS.  相似文献   

16.
Cyanobacteria are a diversified phylum of nitrogen-fixing, photo-oxygenic bacteria able to colonize a wide array of environments. In addition to their fundamental role as diazotrophs, they produce a plethora of bioactive molecules, often as secondary metabolites, exhibiting various biological and ecological functions to be further investigated. Among all the identified species, cyanobacteria are capable to embrace symbiotic relationships in marine environments with organisms such as protozoans, macroalgae, seagrasses, and sponges, up to ascidians and other invertebrates. These symbioses have been demonstrated to dramatically change the cyanobacteria physiology, inducing the production of usually unexpressed bioactive molecules. Indeed, metabolic changes in cyanobacteria engaged in a symbiotic relationship are triggered by an exchange of infochemicals and activate silenced pathways. Drug discovery studies demonstrated that those molecules have interesting biotechnological perspectives. In this review, we explore the cyanobacterial symbioses in marine environments, considering them not only as diazotrophs but taking into consideration exchanges of infochemicals as well and emphasizing both the chemical ecology of relationship and the candidate biotechnological value for pharmaceutical and nutraceutical applications.  相似文献   

17.
Marine cyanobacteria, notably those from tropical regions, are a rich source of bioactive secondary metabolites. Tropical marine cyanobacteria often grow to high densities in the environment, allowing direct isolation of many secondary metabolites from field-collected material. However, in temperate environments culturing is usually required to produce enough biomass for investigations of their chemical constituents. In this work, we cultured a selection of novel and diverse cyanobacteria isolated from the Portuguese coast, and tested their organic extracts in a series of ecologically-relevant bioassays. The majority of the extracts showed activity in at least one of the bioassays, all of which were run in very small scale. Phylogenetically related isolates exhibited different activity profiles, highlighting the value of microdiversity for bioprospection studies. Furthermore, LC-MS analyses of selected active extracts suggested the presence of previously unidentified secondary metabolites. Overall, the screening strategy employed here, in which previously untapped cyanobacterial diversity was combined with multiple bioassays, proved to be a successful strategy and allowed the selection of several strains for further investigations based on their bioactivity profiles.  相似文献   

18.
Microbial natural products are important for the understanding of microbial interactions, chemical defense and communication, and have also served as an inspirational source for numerous pharmaceutical drugs. Tropical marine cyanobacteria have been highlighted as a great source of new natural products, however, few reports have appeared wherein a multi-omics approach has been used to study their natural products potential (i.e., reports are often focused on an individual natural product and its biosynthesis). This study focuses on describing the natural product genetic potential as well as the expressed natural product molecules in benthic tropical cyanobacteria. We collected from several sites around the world and sequenced the genomes of 24 tropical filamentous marine cyanobacteria. The informatics program antiSMASH was used to annotate the major classes of gene clusters. BiG-SCAPE phylum-wide analysis revealed the most promising strains for natural product discovery among these cyanobacteria. LCMS/MS-based metabolomics highlighted the most abundant molecules and molecular classes among 10 of these marine cyanobacterial samples. We observed that despite many genes encoding for peptidic natural products, peptides were not as abundant as lipids and lipopeptides in the chemical extracts. Our results highlight a number of highly interesting biosynthetic gene clusters for genome mining among these cyanobacterial samples.  相似文献   

19.
20.
Marine cyanobacteria have been considered a rich source of secondary metabolites with potential biotechnological applications, namely in the pharmacological field. Chemically diverse compounds were found to induce cytoxicity, anti-inflammatory and antibacterial activities. The potential of marine cyanobacteria as anticancer agents has however been the most explored and, besides cytotoxicity in tumor cell lines, several compounds have emerged as templates for the development of new anticancer drugs. The mechanisms implicated in the cytotoxicity of marine cyanobacteria compounds in tumor cell lines are still largely overlooked but several studies point to an implication in apoptosis. This association has been related to several apoptotic indicators such as cell cycle arrest, mitochondrial dysfunctions and oxidative damage, alterations in caspase cascade, alterations in specific proteins levels and alterations in the membrane sodium dynamics. In the present paper a compilation of the described marine cyanobacterial compounds with potential anticancer properties is presented and a review on the implication of apoptosis as the mechanism of cell death is discussed.  相似文献   

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