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1.
The aim of this study was to investigate the side-effects of fungicides on the physiological activities of plant growth promoting
rhizobacteria with intrinsic phosphate-solubilizing potential. The fungicide-tolerant and phosphate-solubilizing bacterial
strain PS19 was isolated from the mustard rhizosphere and identified as Klebsiella sp. following 16S rDNA sequencing. The Klebsiella sp. strain PS19 normally, produced plant growth promoting (PGP) substances in substantial amount. In this study, four fungicides
of different chemical families (tebuconazole, hexaconazole, metalaxyl, and kitazin) at the recommended, two and three times
of the recommended rates decreased the PGP attributes of the strain PS19 in fungicide-concentration dependent manner. Moreover,
fungicides at the recommended dose had slight inhibitory effect while the dose higher than the recommended ones reduced the
PGP traits (phosphate solubilization, salicylic acid, 2,3-dihydroxy benzoic acid, and indole-3-acetic acid production except
exo-polysaccharides, hydrogen cyanate and ammonia production) significantly. Of the four fungicides, tebuconazole generally
showed the maximum toxicity to the PGP activities of the strain PS19. The results of this study inferred that fungicides,
which are used to control various fungal pests detrimental for the crop productivity, must be examined in vitro for their
possible adverse impacts on plant-beneficial rhizobacteria before the field application. This study also revealed an additional
aspect of the toxicological mechanisms of the fungicides through which they may suppress the plant growth. 相似文献
2.
Potato tuberworm, Phthorimaea operculella Zeller, has become a serious threat to potato production in the Columbia Basin region of Oregon and Washington and in 2005
was found in Idaho. Despite intensive insecticide application, severe defoliation has occurred in recent years indicating
insensitivity of potato tuberworms (PTW) to insecticides. In this study, dose responses of potato tuberworms from a Columbia
Basin field population (CBFP) and a laboratory colony from Colorado (COLC) to three commonly used field crop insecticides
(esfenvalerate, methamidophos and fipronil) were tested. The COLC was included in this study as a standard susceptible colony
but despite being reared in isolation for >30 years, it was resistant to field-labeled rates of all three insecticides used
in this study. The CBFP was also resistant to esfenvalerate and fipronil at field rates but was relatively susceptible (40%
mortality) to methamidophos. At 10× field rate of fipronil, COLC was very susceptible (>90% mortality) but CBFP was not significantly
affected. CBFP was also more resistant to esfenvalerate than COLC. None of the COLC survived a 500× field rate of esfenvalerate;
the same dose killed only 10% of the CBFP. Although further tests are required to more broadly assess the levels and types
of insecticide resistance in these populations, our findings indicated that the laboratory colony was susceptible to fipronil
at dosages somewhat greater than labeled field rates and that the field population was susceptible to methamidophos. Although
COLC was moderately insensitive to esfenvalerate and methamidophos, this laboratory colony was still more broadly susceptible
to field rates than the CBFP. 相似文献
3.
以尾叶桉、黑木相思苗木混栽为研究对象,采用15N土壤和叶片标记法,在温室盆栽下研究2种植物间在根系完全隔离、部分隔离及无隔离处理下的生长变化及N素传递。结果表明:黑木相思的苗高、地径及生物量等生长指标随着根系隔离的减少而逐渐降低;相反,尾叶桉在根系无隔离处理下,其生长指标都要显著高于根系完全隔离处理,结果表明尾叶桉具有强大的养分吸收能力,混栽条件下会抑制黑木相思的生长。在15N土壤或叶片标记下,尾叶桉在根系部分隔离、无隔离下的总15N含量显著高于完全隔离处理(5.0和59.6倍);在土壤标记下,根系无隔离处理的黑木相思总15N含量显著低于完全隔离、部分隔离处理,而在叶片标记下的完全隔离黑木相思,其总15N含量显著低于其余2种处理。无论土壤或是叶片标记,黑木相思都能将N素传递至相邻尾叶桉,其N素传递率、传递量随着根系隔离的减少而提高。研究结果表明尾叶桉、黑木相思间能通过土壤渗透等方式传递N素,为桉树、相思的混交模式提供可靠的理论依据。 相似文献
4.
Reclaiming sodic soils for wheat production by Prosopis juliflora (Swartz) DC afforestation in India
A green house pot trial was conducted to assess the impact of Prosopis afforestation on the productivity and fertility of degraded sodic soils in Haryana, India. Wheat (Triticum aestivum, L; cultivar HD 2329) plants were grown from seed on top soils collected from a chronosequence of 0, 5, 7, and 30-year-old Prosopis juliflora plantations established on highly sodic soils and a non-sodic reference soil collected from a local farm. The afforestation improved physical and chemical properties of surface soils by decreasing pH, electrical conductivity and exchangeable Na levels, and increasing infiltration capacity, organic C, total N, available P, and exchangeable Ca, Mg, and, K levels. The amelioration effect of the trees on top soil increased with duration of tree occupancy. Soil nutrient status under the 30-year-old plantation was higher than that of the non-sodic farm soil. The reduced soil sodicity and improved fertility contributed to higher germination, survival, growth, and grain yield of wheat plants grown on the Prosopis chronosequence soils, even surpassing the yield attained on the farm soil in the case of 30-year-old plantation soil. Sodium accumulation in the crop declined while N, P, K, Ca, and Mg uptake increased with soil plantation age reflecting the changing nutrient status of the rooting zone due to afforestation. Results confirmed that successful tree plantation may restore the productivity and fertility of highly degraded sodic soils. 相似文献
5.
Wen Chao Shen Liming Chen Jian Zhang Jianlong Feng Ying Wang Zhong Chen Xuan Cai Jiacheng Wang Lei He Yinghao Wen Xiujun Ma Tao Wang Cai 《Journal of pest science》2022,95(3):1135-1150
Surface treatment is commonly used in controlling the red imported fire ants, Solenopsis invicta Buren. In the present study, the behavioral responses of S. invicta workers to surfaces treated with insecticides were investigated. Toxicological tests showed that beta-cypermethrin had the highest contact toxicity (with the lowest LC50 value) among nine tested insecticides, followed by thiamethoxam, fipronil, indoxacarb, chlorfenapyr, spinetoram, rotenone, avermectin, and chlorantraniliprole. In the laboratory, surfaces treated with beta-cypermethrin or rotenone significantly reduced the number of foraging ants. In addition, S. invicta workers transported significantly more particles (measured in weight and/or covered area) onto surfaces treated with fipronil (50, 500, and 5000 µg/mL), rotenone (5000 µg/mL), or avermectin (5000 µg/mL) compared with the controls. Similarly, these insecticides significantly triggered the particle-covering behavior of ants in the field. We hypothesized that such behaviors would reduce the contact toxicity of insecticides against S. invicta. When the surfaces treated with fipronil or rotenone (500 or 5000 µg/mL) were artificiality covered with particles, S. invicta had significantly higher LT50 values compared with insecticide-treated surfaces without particles. This study provides the first evidence that S. invicta workers can perform particle-covering behavior to reduce the toxicity of certain insecticides, which constitutes a unique insecticide-resistance strategy in ants.
相似文献6.
采用蒸馏水浸提法收集薄壳山核桃叶及青皮化感物质,运用室内生物测定法检测其不同浓度(0.005、0.01、0.1 g·mL-1)浸提液对小麦、油菜和绿豆种子萌发和幼苗生长的影响。结果表明:薄壳山核桃叶及青皮水浸液处理对3种受体植物的种子萌发和幼苗的苗高基本上表现为"低(0.005 g·mL-1)促高(0.1 g·mL-1)抑"的双重浓度效应,个别受体植物的化感作用虽然表现不同于"低促高抑"的整体趋势,但随着浓度的增加也表现为促进作用降低或抑制作用增强的现象;对3种受体植物根长的抑制作用大于对苗高的抑制作用,而对幼苗鲜质量、干质量的影响则因受体种类的不同而不同。薄壳山核桃叶水浸液处理对3种受体植物的综合化感效应依次为:油菜> 小麦> 绿豆;青皮水浸液处理对3种受体植物的综合化感效应依次为:小麦> 油菜> 绿豆。综合3种受体植物的化感效应认为,在相同浓度下,薄壳山核桃叶水浸液处理对3种受体植物的促进作用最强,而青皮水浸液处理对3种受体植物的抑制作用最强。 相似文献
7.
植物根际促生菌促生机理研究 总被引：3，自引：0，他引：3
化肥与农药的使用虽能促进植物的生长发育,但剂量过大会造成成本上升、土壤质量下降、环境恶化等不良反应.近年来研究发现存在一类自生型细菌称为植物根际促生菌(Plant growth-promoting rhizobacteria,PGPR),能忍受或抵抗植物所遭受的不利环境,进而促进种子萌发和促进植物生长.文章从PGPR的促进植物吸收营养功能、植物生长调节功能、生物防治性能和环境修复功能4个方面阐述,旨在了解PGPR促进植物生长的原理,找出能改善植株抗逆性,缩短生长周期,促进植株更好更快繁殖的方法. 相似文献
8.
植物根围促生细菌的研究进展及在林业上的应用 总被引：1，自引：0，他引：1
植物根围促生细菌（PGPR）通过一种或多种不同的作用机制对植物产生直接或间接的作用从而促进植物生长。综述了PGPR的国内外研究概况以及PGPR的特征,从PGPR促生长作用、PGPR生防功能两方面论述了PGPR在林业上的应用,最后简要介绍了PGPR应用于林业的现实意义。 相似文献
9.
S. M. S. Huda M. Sujauddin S. Shafinat M. S. Uddin 《林业研究》2007,18(4):279-282
A study was conducted to test the influence of different inorganic fertilizers （phosphorous and potassium） on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung （soil： cowdung = 3：1）. Nodulation status （nodule number, shape, fresh weight, dry weight and color） in the roots and the plant growth parameters （length of shoot and root, collar diameter, fresh and dry weight of shoot and root） were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly （P〈0.05） in the soils amended with fertilizers in comparison to the control. The highest nodule number （62）, fresh （0.50 g） and dry （0.07 g） weights were recorded with the dose of PK at the rate of 160 kg/hm2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference （P〈0.05） among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm^2 fertilizer with soil and cowdung mixture （soil： eowdung = 3：1） is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level. 相似文献
10.
Robin Duponnois Marija Kisa Yves Prin Marc Ducousso Christian Plenchette Michel Lepage Antoine Galiana 《New Forests》2008,35(2):105-117
Australian acacias like Acacia holosericea are excellent candidates for the revegetation of arid zones in Africa. Their high ability to develop multiple symbioses with
soil microorganisms is crucial to their rapid development in adverse climatic and edaphic conditions. These symbioses include
nitrogen fixation with rhizobia, vesicular arbuscular mycorrhization and ectomycorrhization. We set up an experiment to test
the growth response of A. holosericea to ectomycorrhizal inoculation in 13 different soils from Senegal. After autoclaving the soil, the experiment was conducted
in a greenhouse for four weeks. Plants were inoculated with Pisolithus albus strain IR100. The following parameters were measured: plant biomass, N, P, K and Ca foliar composition, spontaneous nodulation
rate, and ectomycorrhizal colonization. Data were analyzed in light of the physical, chemical and total microbial characteristics
of the soil. The results demonstrated a global promoting effect of P. albus inoculation on plant (shoot and root) growth and on foliar P and K, together with a depressive effect on N, while Ca rates
were barely affected. Interestingly, spontaneous nodulation with putative water- or airborne rhizobia was stimulated after
P. albus inoculation. However, these nodules seemed poorly effective, as they failed to cause any change in plant growth or in foliar
N composition within the nodulated and nonnodulated control plants. These results show that plant growth response to ectomycorrhizal
inoculation is greatly dependent on soil characteristics, and that root ectomycorrhizal colonization is influenced by biotic
factors such as soil microbiota. From a practical point of view, data from the present study demonstrate that it is possible
to optimize the effect of fungi on plant growth by screening soils under nursery conditions. 相似文献
11.
拟南芥 AtFBDL1 基因是FBD-like基因家族的一员,其编码蛋白含有类似于F-box的结构域。表达模式网络预测结果显示该基因在茎顶端分生组织中高丰度表达,但对于FBD-like基因家族的研究还很少,其功能目前尚不明确。为此,本研究通过组织半定量表达分析和GUS染色显示 AtFBDL1 基因在拟南芥中具有时空表达特异性。结果表明:在真叶形成前和形成初期,该基因主要在茎顶端分生组织和下胚轴区域表达;真叶形成后,该基因在下胚轴的表达明显减少,而主要集中在茎顶端分生组织表达。遗传转化显示:与野生型植株相比,过表达 AtFBDL1 基因的植株生长发育缓慢,抽薹时间推迟3 4 d,莲座叶叶片面积减小,叶片数目平均增多10片,并且伴随有变态叶出现;过表达植株株高比野生型矮,株高最大差值达到12 cm。共表达网络预测 AtFBDL1 与多个与生长素和花发育相关的基因具有共表达关系。以上研究结果表明: AtFBDL1 基因在拟南芥的生长发育过程中,特别是在顶端分生组织分化过程中起重要作用。 相似文献
12.
Coccinella undecimpunctata L. is a euryphagous predator established in Azores that offers interesting potential as a control agent in the context of
integrated pest management (IPM). However, to further develop IPM against aphids, it is important to evaluate the effects
that insecticides might have on voracity. Thus, we proposed to evaluate the effects of pirimicarb and pymetrozine on the voracity
of 4th instar larvae and adults of C. undecimpunctata, under distinct scenarios of exposure to chemicals within a prey/plant system. Voracity of C. undecimpunctata was not significantly affected by pirimicarb or pymetrozine when treatments were directly sprayed on the predator; however,
when insecticides were sprayed on the prey/plant system, the predator’s voracity was significantly increased. Results suggest
that C. undecimpunctata does not detect the insecticide on the aphids and indicate that the increase in voracity may be due to a decrease in the
mobility of insecticide-treated aphids, since their capture should be easier than highly mobile non-treated prey. The consequences
of such increase in the voracity for IPM programs are discussed. 相似文献
13.
[目的]本研究旨在探索与挖掘胡杨基因组大片段的潜在功能,发掘具有潜在育种价值的胡杨基因簇。[方法]利用已构建的胡杨基因组BIBAC文库,采用花序浸染法,将胡杨基因组大片段78A2D10导入模式植物拟南芥基因组中。采用抗性筛选、分子检测及表型观察等方法鉴定、分析转化型植株。[结果]共获得15株特异表型的转化植株。与野生型相比,转化型植株主侧茎生长受到抑制,莲座叶面积增大近3倍,叶片数量增多,叶边缘皱缩,抽薹推迟约13周,株高增加近32.0 cm,侧茎发育成次生莲座,植株寿命延长约7周。[结论]胡杨基因组片段78A2D10可延长植株营养生长期及植株寿命,据此推测该基因片段可能与营养生长有关。 相似文献
14.
[目的]模式植物在木本植物中鉴定的许多重要调控因子家族在木本植物中出现了基因家族成员扩张,但ARRs家族作为细胞分裂素响应调节因子在杨树基因组中成员数量反而减少,其在木本植物中如何行使功能需要进一步研究。[方法]本研究通过生物信息学构建PtRRI启动子与GUS融合表达载体,检测植物激素处理后PtRRI表达量和检测PPtRRI::GUS转基因植株在生根过程中GUS信号等方法,对杨树PtRRI基因的组织特异性表达模式进行分析。[结果]表明:PtRRI在杨树根部、形成层、木质部表达量相对较高,PtRRI转录受6-BA激素诱导,与其在不定根发育过程中激素调控下的表达相一致。[结论]PtRRI基因可能参与杨树的次级生长。 相似文献
15.
Marcela C. Pagano Marta N. Cabello Antonio F. Bellote Nadja M. Sá Maria Rita Scotti 《Agroforestry Systems》2008,74(3):231-242
For the purpose of reforestation and wood supply the leguminous tree Anadenanthera peregrina, a native species, was intercropped with Eucalyptus camaldulensis in a degraded semiarid area of Brazil. Single and mixed stands of these species were inoculated with Rhizobium and/or arbuscular mycorrhizal fungi (AMF). The growth of all species in mixed stands did not differ from those cultivated
in monoculture and land equivalent ratio (LER) exceeded unity in intercropped plots. Inoculated plants showed greater height
and diameter growth and dry matter and nutrient concentration in plants of A. peregrina was higher in inoculated single plots. The distribution, composition and density of AMF species was related to the rhizosphere
effect of plant species. The intercropped model where all the plants were inoculated achieved soil AMF diversity patterns
similar to those of the preserved area and showed also higher soil organic matter, nutrient content as well as a reduction
in soil macroporosity. This model of intercropping may be considered as an efficient system for reforestation under semiarid
conditions. 相似文献
16.
生长素及其信号转导系统对植物的生长发育具有重要的影响。本研究从银腺杨'84K'(Populus alba × P. glandulosa cl. '84K')中分离了生长素受体基因PtrFBL1,利用PMDC32构建了PMDC32-PtrFBL1超量表达载体,并通过遗传转化获得了超量表达植株17个。对温室定植的3个转基因株系和对照植株的根系、生长量和光合指标等性状分析结果显示:转基因株系总根长和总根面积达到显著或极显著差异,而根系干质量、平均不定根系长度、平均不定根直径差异不显著;株高、平均节间长、地径和高径比皆高于对照,且大多数转基因株系达到显著差异;除气孔限制值(Ls)低于对照外,气孔导度(Cd)、水分利用效率(WUE)、光能利用效率(LUE)和叶绿素相对含量皆高于对照,且大多数转基因株系达到显著或极显著差异。以上结果表明,可能是FBL1超表达增加了转基因株系根系面积,提高了水分和养分的吸收利用,进而导致转基因株系光能吸收和转化效率提高,引起转基因株系生长加快。 相似文献
17.
Wehner Gwendolin Schikora Adam Ordon Frank Will Torsten 《Journal of pest science》2021,94(4):1237-1247
Plants have developed numerous strategies for responding to abiotic and biotic stresses. In particular, the microbiota surrounding plants may have a positive effect on plant stress responses. One is the reaction to rhizobacteria, which can lead to induced systemic resistance. Gram-negative soil bacteria that produce N-acyl homoserine lactones (AHL), for example, Ensifer meliloti, induce a primed state in plants that is part of the inducible resistance phenomenon. Observing Rhopalosiphum padi feeding behaviour on a priming sensitive barley genotype, treated with the AHL-producing E. meliloti strain expR?+?ch, using electrical penetration graph technique showed decreased ingestion of food. Aphids appear to overcome this effect within the eight-hour observation period, possibly explaining the absence of differences of reproduction. Reproduction was observed for a period of 14 days on primed and control-treated plants. Long-term observations over a period of 40 days after aphid infestation showed a lower aphid biomass in contrast to a control group, interpreted as delayed population growth, and an increase in the biomass of barley plants. Priming-related genotypic effects of the defence response to aphids were observed, with no beneficial effects on the plant genotype when its sensitivity to priming was low. Previously, an AHL-priming sensitive barley genotype showed enhanced resistance against fungi when primed with the expR?+?ch strain of E. meliloti. The present study reports the same effect against R. padi. These findings suggest that sensitivity to AHL-priming may represent a new approach for plant breeding, targeting multiple pests in parallel by induced plant resistance.
相似文献18.
糖基化磷脂酰肌醇锚定蛋白(GPIAP)因其结构和功能的多样性,决定了它在各种生物学过程中都发挥着重要作用。采用同源克隆的方法从绿竹(Bambusa oldhamii)中获得一个GPIAP同源基因,命名为BoGPIAP,cDNA全长1 772 bp,其中包括1 356 bp的开放阅读框,编码一个451 aa的的蛋白。蛋白结构分析表明,该蛋白包含1个典型的GPIAP家族保守区域(47-211)和1个CCVS结构域,在N-端和C-端分别具有1个跨膜信号肽和1个GPI锚定信号肽,属于GPIAP家族。构建BoGPIAP与GFP融合的表达载体,在洋葱表皮细胞中瞬时表达,结果显示BoCOBL::GFP融合蛋白定位于细胞膜上,证明BoGPIAP基因编码的蛋白为膜蛋白。分别构建BoGPIAP的正义、反义表达载体并转化烟草(Nicotiana tabacum)。PCR检测结果表明,BoGPIAP已转入烟草。与野生型相比,转反义基因植株细弱,纤维细胞壁明显变薄;而转正义基因植株粗壮,纤维细胞壁明显变厚。表明BoGPIAP可能对竹子纤维细胞壁的发育具有调控作用。 相似文献
19.
A study was carried out on Rosellinia necatrix attack on young woody plants, as possibly affected by selected soil features under three water regimes. Six different soil systems representing five agro‐environments and one forest in the Puglia Region (southern Italy – Mediterranean climate) were compared. R. necatrix attack on sweet cherry trees was simulated using artificial inoculum and saplings of Prunus mahaleb, the most widely used rootstock of sweet and sour cherries, monitored during the spring period. Soil features significantly influenced disease score, which did not differ from one water regime to another, even though disease level in the different soils was affected by water content. Rosellinia mahaleb saplings grown in forest soil showed the highest disease score, which differed significantly from that observed in all the agricultural soils tested in this study. Amongst these, disease score was lower in sandy soils than in soils that were richer in loamy fraction. 相似文献
20.
Katri Luostarinen Katja Hakkarainen Henri Kaksonen 《Scandinavian Journal of Forest Research》2017,32(8):789-797
Soil affects the anatomy of downy birch wood (Betula pubescens), which raises the question whether the growth of this species differs between mineral and peat soils. The aim of this study was to compare growth, density and structure of xylem of B. pubescens between trees grown in different soils. Both growth and density differed between trees grown in different soils. All measured anatomical characteristics, except double thickness of fibre walls, percentage vessel area and ray number, showed differences between the soil types: the cell dimensions were larger and numbers smaller in trees grown in mineral soil. In peat, high growth rates decreased the wall:lumen ratio of fibres in maturing wood, while no such correlation was observed in trees grown in mineral soil at any studied cambial age. In addition, axial parenchyma may have a different role in trees grown in different soils, as the rapid growth decreased and increased axial parenchyma in mineral and peat soil, respectively. The characteristics affecting wood strength were more similar between trees grown in different soils than those affecting water conductance. The observed differences between trees grown in different soils emphasise rapid growth particularly at young ages and shorter reasonable rotation period in mineral soil. 相似文献