蕺菜属植物富钾基因型的筛选

在低钾土壤培养和营养液培养的条件下,采用植株含钾量、吸钾速率和钾素利用率并结合植株根系形态特征,对蕺菜属(Houttuynia Thunb.)16份不同基因型材料的富钾能力进行筛选.结果表明,峨眉蕺菜W01-86以及蕺菜W01-34和W01-71在低钾土壤培养和溶液培养时植株含钾量分别高于9.0%,5.50%,吸钾速率大于1.50μmol/(g·h).低钾土壤培养和溶液培养时的钾素利用率分别高于2.50,0.30g/g,为富钾基因型;W01-4和W01-99低钾土壤培养和溶液培养时的植株含钾量分别低于8.5%,5.0%,吸钾速率小于0.65μmol/(g·h),低钾土壤培养和溶液培养时的钾素利用率分别低于2.00,0.30 g/g,为低钾基因型.     

烟草含钾量的基因型差异及钾高效品种筛选

【目的】高含钾量是优质烟叶的一项重要指标。比较不同烟草品种的含钾量及其对施用钾肥的反应,为筛选高钾基因型烟草品种提供基础。【方法】以 93 份烟草种质资源为研究对象,在凉山州进行连续两年的大田试验。设置常规钾 (K₂O = 300 kg/hm2) 与低钾 (K₂O = 150 kg/hm2) 两个水平,成熟期测定烟叶含钾量,以聚类分析将烟草分类,并分析其在不同叶位间的基因型差异。【结果】施钾量影响烟草上、中、下部叶片钾含量,常规钾水平下的烟叶含钾量高于低钾水平,常规施钾量下的上、中、下部烟叶含钾量分别为低钾水平下的 1.13、1.14、1.15 倍 (2014 年) 和 1.10、1.25、1.35 倍 (2015 年) 。将烟叶含钾量进行聚类分析,供试材料被划分为高钾型、普通型和低钾型 3 类,并筛选获得了典型材料。高钾型烟草的上、中、下部烟叶含钾量均显著高于普通型及低钾型烟草材料。常规施钾水平下,高钾型烟草的上、中、下部烟叶含钾量分别是低钾型的 1.50～1.92、1.54～2.52、1.31～2.36 倍;低钾水平下分别为 1.27～1.93、1.66～2.24、1.72～1.73 倍。【结论】高钾基因型烟草上、中、下部烟叶的含钾量均显著高于普通型和低钾型;普通型上部叶的含钾量与低钾型烟草之间无显著差异,中、下部烟叶含钾量普通型显著高于低钾基因型。通过两年田间试验筛选获得了 6 份高钾型烟草材料,包括嘎吉红大、长叶红大、达白 1 号、达白 2 号、MFZS、930032-7,可应用于烟叶生产,亦可为富钾基因型品种选育提供育种亲本材料。     

籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用

通过大田和模拟试验等方法 ,研究了籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用 ,研究结果表明 :(1)籽粒苋根际土壤的速效钾含量较非根际土增加了 1.7倍 ,缓效钾 (K)的含量也提高了 5 5 .9% ;(2 )用籽粒苋根际土壤处理后的花岗岩粉末 ,其速效钾和缓效钾含量均较对照有所增加 ,增幅分别为 2 .8%～ 2 4.7%和 15 .7%～ 44 .7% ;用籽粒苋根际土壤处理后的紫色土 ,其速效钾和缓效钾含量较对照分别增加了 18.5 %和 11.1% ;(3 )通过对y值的综合贡献率计算可知 ,不同籽粒苋模拟根系分泌物对花岗岩粉末中矿物态钾的活化能力大小依次为 :草酸 >蔗糖 >核酸 >乳酸 >柠檬酸。     

水稻钾素营养的根际效应

关于淹水条件下根际效应的研究迄今很少。而淹水土壤的根际环境与早作土壤十分不同。     

烟草根际土壤中解钾细菌的分离与多样性分析

土壤中含有丰富的钾元素,但主要以缓效态形式存在于钾长石或云母等硅酸盐矿物中,不能被作物直接吸收利用。解钾微生物能溶解硅酸盐矿物中的钾,提高土壤中作物可利用钾的含量,有望缓解我国钾肥短缺的现状。本研究利用选择性培养基,从烟草根际筛选钾细菌,基于16S rDNA序列分析烟草根际土壤解钾细菌的多样性,通过测定解钾细菌的解钾效能及对烟草的促生作用,筛选有应用潜力的优良解钾细菌菌株。结果表明,从四川、湖北和山东烟区烟草根际土壤分离获得的27株解钾细菌,在解钾固体培养上溶钾圈直径为0.11~0.30 cm。16S rDNA序列分析表明,烟草根际土壤解钾细菌主要包括变形菌门γ亚群(Gammaproteobacteria,85.18%)、变形菌门α亚群(Alphaproteobacteria,3.70%)、变形菌门β亚群(Betaproteobacteria,3.70%)、放线菌门(Actinobacteria,3.70%)和拟杆菌门(Bacteroidetes,3.70%),其中克雷伯菌属(Klebsiella)为优势菌属(66.67%)。27个菌株均有一定的解钾能力,解钾活性为0.59~4.40 mg.L–1。参试菌株均对烟草有一定的促生作用,利用解钾细菌菌液处理烟株20 d后,与对照相比,株高增加0.97%~38.64%,最大叶长增加4.40%~31.02%。本研究筛选出的菌株XF11、GM2、JM19和GL7具有较高的解钾活性和促进植物生长的能力,展现了良好的应用潜力。     

铬处理下超富集植物李氏禾根际溶解氧时空分布特征

植物根系泌氧能改变土壤氧化还原电位，影响重金属形态及生物有效性，是重金属污染土壤植物修复效率的重要影响因素。本文基于平面光极原位高分辨技术，在0、50、100 mg/kg等3个铬浓度下研究了铬超富集植物李氏禾根际溶解氧的时空分布特征。结果表明，李氏禾根际土壤中溶解氧浓度较高的热区集中于根系周围区域，在根尖位置溶解氧浓度较高。根际溶解氧含量显著高于非根际土壤，且距离根部越远溶解氧平均含量越低，其中100 mg/kg铬处理组李氏禾根部中心位置土壤溶解氧浓度为距离中心位置5 mm处土壤溶解氧浓度的1.45倍。在8天的拍摄周期中，对照组根部中心位置溶解氧浓度最高达77.2%，显著高于50 mg/kg铬处理组的50.2%和100 mg/kg铬处理组的42.3%。此外，3个铬浓度下李氏禾根际溶解氧浓度都呈现先升高后降低的规律，第4天达到最高值。铬处理下李氏禾根际溶解氧浓度明显下降，这可能是李氏禾为避免根际富氧环境将Cr(III)氧化为毒性更强Cr(VI)的保护性行为。     

小麦根际解钾微生物与土壤钾含量、钾素利用率及根系活力的关系

[目的]探讨肥料施用方式和施钾量对土壤不同形态钾含量及小麦根系活力的影响,以期为提高土壤钾素利用效率提供技术支持.[方法]2018—2020年连续两年,采用裂裂区设计,主区为肥料(A):设20％ 有机肥(鸡粪)+80％ 氮肥(A1),100％ 氮肥(A2)2个水平;副区为施钾量(B):设不施钾(B1)、减量施钾80 k...     

根际动态过程与植物营养

养分的有效性是由土壤物理、化学和生物学特性,特别是根系主导的根际动态过程所决定的。根系引起根际pH值和氧化还原电位、根分泌物以及由此引起微生物种群、数量和活性的改变,从根本上决定着根际养分的动态。而根系主导的根际动态又具有明显的基因型差异,并受植物营养状况的诱导和调控。因此,根际动态变化的方向和强度对植物适应土壤化学和物理逆境具有重要意义。本文从根际的一般概念入手,综述了近十余年来国内外根际动态研究的新成果,重点讨论了根际动态与植物营养的关系,并运用根际微生态系统的概念,把根际动态与植物对养分胁迫的适应性及其调控机理紧密联系起来,使根际动态和植物矿质营养基因型差异机理两个基础性研究热点融为一体,为解决重大的全球性环境、生态以及农业持续发展问题提供新的途径和理论依据。     

根分泌物对根际微生物生态分布的影响

本文从根分泌概念着手 ,依据近 2 0年来国内外有关根分泌研究的一些成果 ,就根分泌物的概念、产生机制进行了综合论述 ,并重点讨论了植物根分泌物对根际微生物代谢、生态分布、病原微生物抑制作用的影响以及土壤环境对根分泌物的影响。     

湿地植物铅的富集特征及根际铅移动性的影响因素研究

【目的】 揭示湿地植物铅的富集特征及根际铅移动性影响因素的作用机理,为人工湿地修复重金属污染水体提供理论指导和依据。 【方法】 通过根箱法研究了五种挺水湿地植物 (大叶皇冠草、黑籽荸荠、圆币草、草龙、小婆婆纳) 根际 pH、氧化还原电位 (Eh)、Fe2+ 和 Fe3+ 浓度、铅 (Pb) 的化学形态及移动性的变化。 【结果】 与非根际相比,五种植物根际pH下降,Fe2+ 和 Fe3+ 浓度显著下降,Eh显著升高,Pb的移动性显著降低 (P<0.05)。与非根际相比,根际pH下降幅度为 0.1～0.4个单位,根际Fe2+和 Fe3+浓度下降幅度为0.6～2.7 mmol/kg。土壤中铅的存在形态主要以残渣态为主 (36.39%～47.54%),其次是铁锰氧化物结合态 (30.16%～41.64%)、有机质结合态 (8.85%～15.08%) 和碳酸盐结合态 (6.89%～12.46%)。五种湿地植物根际Pb的移动性降低的主要原因是根际碳酸盐结合态Pb含量显著下降,其中大叶皇冠草受根际pH、Eh、Fe3+和Fe2+的影响导致其根际Pb移动性降低效应最为显著。 【结论】 五种供试植物Pb主要分布在根部;根表富集的铁膜数量显著高于锰膜数量;供试植物根际Fe3+含量与Pb的移动性因子呈极显著正相关,湿地植物根系铁氧化能力对降低其根际重金属的移动性有重要作用。本研究为人工湿地修复重金属污染水体提供了有力的理论依据。      

Effects of plant age on nitrogen uptake and distribution by greenhouse plants

Water‐soluble nitrogen (N) fertilizer is intensively used in greenhouse crop production. Any N not used by a crop is subject to leaching as nitrate (NO₃‐N), which may pollute groundwater. A close correlation between N supply and N uptake by plants would increase the efficiency of N fertilization and minimize the possibility of NO₃‐N pollution. The objectives of this study were to measure N uptake by American marigold (Tagetes erecta L. ‘First Lady') and New Guinea Impatiens (NGI) (Impatiens hawkeri Bull. ‘Selenia') during growth, to determine the effect of plant age on N uptake, to determine if the two species have a preference for NO₃‐N or ammonium (NH₄‐N), and to determine the total N required for 70 days of growth.The plants were grown in solution culture using solutions supplying 120 mg each of NO₃‐N and NH₄‐N. At ten day intervals, six cultures were chosen at random for nutrient solution analysis and plant sampling for dry weight and tissue analysis. Nitrate‐N uptake was greater than NH₄‐N uptake throughout the experiment for both marigold and NGI. Total N uptake by marigold was greater during the first 50 days after transplanting with maximum N uptake during the period 30 to 50 days. In contrast, N uptake by NGI was greater during the period 40 to 70 days after transplanting. Maximum N uptake for NGI occurred during the period 60 to 70 days. Results of this study suggest that early N fertilization of marigold could be more important for their growth and quality than N applied later. For NGI, N fertilization later in the crop's development appears to be more important than early on. The total N absorbed by marigold during the experiment was 1.1 gm N plant^‐1; for NGI the quantity was 0.5 gm N plant‐¹.     

机械损伤对烤烟植株氮素吸收及体内烟碱含量的影响

采用砂培和营养液培养方法,研究了在营养生长阶段切除顶芽和叶片损伤对烟株生长、体内烟碱浓度、氮浓度及吸氮量的影响。结果表明,切除顶芽导致烟株体内烟碱浓度和含量显著增加。叶片损伤也能增加体内的烟碱浓度,且损伤二次比损伤一次的效果更为明显,说明叶面损伤对烟株体内烟碱合成的影响具有累积效应。但叶面损伤对烟株体内烟碱合成的影响小于打顶处理。切除顶芽和叶面损伤对烟株体内的氮浓度及吸氮量均无显著影响,但显著提高了烟株体内单位氮素产生烟碱的能力。试验结果还表明,机械损伤刺激烟株体内烟碱的合成,烟碱增加与氮素吸收无直接关系。     

植物促生菌接种对中国芥蓝根际固有微生物群落结构的影响

Plant growth-promoting rhizobacteria (PGPR) have been widely recognized as an important agent,especially as a biofertilizer,in agricultural systems.The objectives of this study were to select efective PGPR for Chinese kale (Brassica oleracea var.alboglabra) cultivation and to investigate the efect of their inoculation on indigenous microbial community structure.The Bacillus sp.SUT1 and Pseudomonas sp.SUT19 were selected for determining the efficiency in promoting Chinese kale growth in both pot and field experiments.In the field experiment,PGPR amended with compost gave the highest yields among all treatments.The Chinese kale growth promotion may be directly afected by PGPR inoculation.The changes of microbial community structure in the rhizosphere of Chinese kale following PGPR inoculation were examined by denaturing gradient gel electrophoresis (DGGE) and principal coordinate analysis.The DGGE fingerprints of 16S rDNA amplified from total community DNA in the rhizosphere confirmed that our isolates were established in the rhizosphere throughout this study.The microbial community structures were slightly diferent among all the treatments,and the major changes depended on stages of plant growth.DNA sequencing of excised DGGE bands showed that the dominant species in microbial community structure in the rhizosphere were not mainly interfered by PGPR,but strongly influenced by plant development.The microbial diversity as revealed by diversity indices was not diferent between the PGPR-inoculated and uninoculated treatments.In addition,the rhizosphere soil had more influence on eubacterial diversity,whereas it did not afect archaebacterial and fungal diversities.     

EDDS对印度芥菜Cu积累的影响及与P-ATPase的关系研究

通过水培的方法研究了可降解螯合剂EDDS对印度芥菜对Cu积累的影响,分析了根系中与Cu主动排出有关的P型ATPase的活性及其基因表达。结果表明:根系中Cu的积累量随外界浓度的升高而升高,但Cu在茎杆与叶片中的积累量则变化不大。随着外加EDDS浓度的增加,根、茎、叶中的Cu的积累量均出现下降的趋势。上述结果表明,根系以Cu离子为主要的吸收形式,而不是EDDS-Cu。通过对印度芥菜根系细胞膜上P型ATPase活性及基因表达分析后发现,不加EDDS时,随着外界Cu浓度的升高,ATPase活性增强,而当Cu达到16μmol L-1时出现降低的趋势。但是,ATPase活性随着外加EDDS的浓度增加而降低,这是因为EDDS降低了外界的Cu活度。RT-PCR分析结果表明,该ATPase的基因(BjHMA)在转录水平上的表达与活性变化一致。由于P型ATPase的作用是将Cu排出细胞,因此上述结果说明,其活性大小以及转录水平的变化受到外界Cu离子活度的影响,在一定的范围内可以调节植物对Cu的积累。     

玉米根际高效固氮菌Sphingomonas sp. GD542的分离鉴定及接种效果初步研究

固氮微生物菌种选育是固氮微生物肥料生产应用的基础。本研究从玉米根际土壤分离到1株高效固氮菌株GD542,菌体短杆状,0.4μm×1.0～1.5μm,革兰氏阴性;固氮酶活性为5.046nmol(C2H4)·h-1·mg-1(蛋白);利用碳源较广泛,抗逆性较强,既可在4℃低温生长,也可以在37℃下生长,耐盐性高达10%。16SrDNA序列分析结果表明,该菌株与鞘氨醇单孢菌Sphingomonas azotifigens的16SrDNA序列有高达96%的同源性,结合形态特征和生理生化特征等,将其初步鉴定为鞘氨醇单孢菌Sphingomonas sp.。接种小白菜的温室盆栽试验表明,菌株GD542具有很好的固氮效能,与无氮对照相比,接种GD542处理植株干重增加206%,含氮量增加230%,达到统计学显著差异水平,开发应用前景较好。     

Organic phosphorus compounds as a phosphorus source for higher plants through the activity of phosphatases produced by plant roots and microorganisms

Summary The efficiency of phosphatases produced by clover, barley, oats and wheat was investigated in soils treated with sodium glycerophosphate, lecithin and phytin. Root exudates of aseptically grown clover were also examined for the breakdown of different organic P compounds in order to test the efficiency of plant-produced phosphatases. In general, the plants were able to use P from all the organic sources used in the study almost as efficiently as inorganic sources. Dry-matter yield, P uptake, acid and alkaline phosphatase activity and microbial population were increased in all the P treatments. Organic P enhanced alkaline phosphatase activity. Lecithin increased fungal, and phytin bacterial growth. There was no alkaline phosphatase activity in the asepticallly grown clover root exudates. Phosphatase released in aseptic culture after 4 weeks of clover growth was able to efficiently hydrolyse sodium glycerophosphate, lecithin and phytin. The amount of organic P hydrolysed in this and in the soil experiment surpassed plant uptake by a factor of 20. This suggests that the limiting factor on plant utilization of organic P is the availability of hydrolysable organic P sources.     

A forage grass and small grain legume plant collecting expedition in South East Poland, 1990

Summary The Plant Genetic Resources Unit (PGRU) of the Institute of Grassland and Environmental Research, Welsh Plant Breeding Station (IGER, WPBS), UK, and the Plant Genetic Resources Section of the Plant Breeding and Acclimatization Institute (PBAI), Poland, carried out a joint collecting expedition in Poland between 25 August and 7 September 1990. The expedition was unique in that it was the first time that vegetative sampling had been applied to the perennial forage grass and legume populations of south east Poland. The expedition focused on seminatural vegetation in agriculturally managed situations and detailed collection site data on management systems was obtained from landowners.Samples were collected from 62 sites. Vegetative collections of Lolium spp. (37 populations) and Trifolium spp. (56 populations), and seed collections of Festuca spp. (32 populations) were made by the IGER team (Table 2). The PBAI team made 59 separate seed collections, mainly of Leguminosae.The expedition covered four geographical subregions of south east Poland. (See Fig. 1). These were the Nizina Mazowiecka south of Warszawa, the Wyzyna Malopolska with the town of Kielce at its centre and the Beskidy Zachodnie and Beskidy Wschodnie regions of the Carpathian mountains.A diverse range of habitats was sampled covering a broad range of altitude agricultural management systems and ecological conditions. Polish agriculture is faced with the problems of a rapid orientation to a market economy and it is likely that the diverse range of habitats encoutered will be reduced as agricultural practices change. This will lead to genetic erosion of the unique forage grass and legume populations to be found in Poland.Abbreviations ECP/GR European Co-operative Programme on Crop Genetic Resources - IGER Institute of Grassland and Environmental Research - PBAI Plant Breeding and Acclimatization Institute - PGRU Plant Genetic Resources Unit - WPBS Welsh Plant Breeding Station     

运用多隔层根箱研究黑麦草根际微域中芘的降解

采用多隔层根箱,通过尼龙撩网插片的控制,实现根室土(S0)、离根室0～2 mm(S1)、2～4 mm(S2)、4～6 mm(S3)及>6 mm(S4)各室层土壤的分离采集,测定各室层土壤可提取态芘含量、土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性。结果表明:种植黑麦草处理的各室层内土壤可提取态芘含量存在显著的不同,可提取态芘含量在各室层的大小顺序为S4>S3>S0>S2>S1;各室层土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性表现出与可提取态芘含量变化相反的趋势。未种植黑麦草处理的各室层土壤可提取态芘含量、土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性没有差异。种植黑麦草处理各室层土壤可提取态芘含量与土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶活性和多酚氧化酶活性之间均存在显著的负相关性(p<0.05)。主成分分析结果表明种植黑麦草处理土壤微生物活性在各室层间发生了明显的变化。     

Survival and competitiveness of Bradyrhizobium sp. in the rhizosphere of pigeonpea (Cajanus cajan)

Summary The survival of Bradyrhizobium Cajanus strain CC1021 in the soil and rhizosphere of pigeonpea [Cajanus cajan (L.) Millsp] was determined by most probable number and fluorescent antibody techniques. The survival of strain CC1021 was poor under field compared with pot-culture conditions. Although the rhizosphere of pigeonpea promoted the growth of native pigeonpea rhizobia, although no increase in the number of rhizobia was observed with the inoculant strain. Under similar conditions of rhizosphere colonization the competitiveness of strain CC1021 with cv UPAS 120 and ICPL 312 was 10% and 66016 during the first year and 8.4% and 33.3%, respectively, during the second year.