Antagonistic and plant growth activity of Trichoderma isolates of Western Himalayas

The genus Trichoderma is rapidly growing colonies bearing tufted or postulate, repeatedly branched conidiophores with lageniform phialides and hyaline or green conidia born in slimy heads. 62 isolates of Trichoderma species were isolated from different rhizospheric soil samples collected from different places located in Western Himalayas region. Out of these only two species were found i.e. Trichoderma hazianum and Trichoderma viride. Their efficacy against soil borne plant pathogens like Sclerotium rolfsii, Rhizoctonia solani and Sclerotinia sclerotiorum revealed that only three isolates amounting to 5% of the total collected isolates of this region were found highly antagonist. Among them 5% isolates were found against S. rolfsii, 13% isolates against R. solani, 10% against sclerotium caused above 80% inhibition of mycelial growth respectively. 6% isolates out of twenty seven utilized chitin by more than 80 and 16% isolates consumed cellulose by above 80% and therefore are producers of chitinase and cellulases. 58% isolates produced colonies having cottony texture and 41% produced dark green colonies. Pigmentation as observed from reverse side of the colony revealed that 70% of them did not produced pigment in the medium. Plant growth promotion measured as root and shoot lengths were significantly higher than in control. The maximum root length and shoot length were recorded when seeds were treated with isolates were recorded at Srinagar Garhwal was 4.70 and 4.75 cm out of all the isolates in which isolate recorded from Srinagar no 3 caused maximum percent seed germination which was significantly higher 79.49%.     

PBS降解过程对植物发芽和生理特性的影响研究

采用青菜（Green vegetables）和生菜（Romaine lettuce）的种子发芽和室外盆栽实验,通过考察植物的种子发芽、生物量以及叶绿素质量浓度等指标,研究了可生物降解材料聚丁二酸丁二醇酯（PBS）对青菜和生菜发芽和生长过程中生理特性（植株地上鲜、干质量,地下鲜、干质量,株高,根长,叶片数,叶绿素质量浓度）的影响。研究结果表明：（1）土壤中加入PBS有利于青菜种子的发芽,较大幅度的提高了其发芽率、苗长、根长等,并且随着PBS质量分数的增加这种促进作用越发明显,PBS×100处理组的苗长和根长较空白对照组分别增长了12.9%和26.1%;（2）低质量分数的PBS对青菜和生菜的发芽、生长以及叶绿素的合成具有一定的促进作用,但是高质量分数的PBS则会产生轻微的抑制作用。     

Influence of short-term irrigation of textile mill wastewater on the growth of chickpea cultivars

The effect of textile mill wastewater on germination, delay index, physiological growth parameters, and plant pigments of two cultivars of chickpea was studied. The aim of this study was to evaluate the suitability of textile mill wastewater (treated and untreated) at different concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) for irrigational purposes. The textile effluent did not show any inhibitory effect on seed germination at a lower concentration (6.25%). The other reported plant parameters (delay index, root length, shoot length, dry weight, chlorophyll, and carotenoid) also followed a similar trend. Seeds germinated in 100% effluents but did not survive for longer periods. It has also been concluded that the effect of the textile effluent is cultivar-specific, and due care should be taken before using the textile mill wastewater for irrigation purposes.     

Influence of short-term irrigation of textile mill wastewater on the growth of chickpea cultivars

The effect of textile mill wastewater on germination, delay index, physiological growth parameters, and plant pigments of two cultivars of chickpea was studied. The aim of this study was to evaluate the suitability of textile mill wastewater (treated and untreated) at different concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) for irrigational purposes. The textile effluent did not show any inhibitory effect on seed germination at a lower concentration (6.25%). The other reported plant parameters (delay index, root length, shoot length, dry weight, chlorophyll, and carotenoid) also followed a similar trend. Seeds germinated in 100% effluents but did not survive for longer periods. It has also been concluded that the effect of the textile effluent is cultivar-specific, and due care should be taken before using the textile mill wastewater for irrigation purposes.     

Studies on phytotoxic effect of aluminium on growth and some morphological parameters of Vigna radiata L. Wilczek

Aluminium toxicity is a major deterrent for plant growth in acid soils below pH 5.0. This study deals with effect of aluminium toxicity on growth of mungbean (Vigna radiata L. Wilczek) seedlings. Seed germination (in %) declined with increased content of Al2(SO4)3, while promotive effect was observed at very low dosage. Different concentrations of aluminum sulphate salt were applied to mungbean seeds. Measurement of aluminium content in mungbean leaves was done through atomic absorption spectrophotometer. Root length (root and hypocotyl length) and shoot length (shoot and epicotyl length) was measured at seven days old seedling stage. Different concentrations of Al2(SO4)3 were found to have significant effect both on shoot and root length. Leaf area, fresh and dry weight was significantly reduced. Increased stomatal frequency and trichome density with an increase in concentrations of Al2(S04)3 was observed through scanning electron microscope.     

Studies on seed germination and growth in weed species of rice field under salinity stress

An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated seeds were recorded daily. The final germination percentage, germination index (GI), seedling vigour index, mean germination time and time for 50% germination were estimated. Root and shoot lengths of the weed seedlings were measured at 20 days after salt application and relative growth values were calculated. Results revealed that salinity decreased final germination percentage, seed of germination as measured by GI, and shoot and root length in all the species. Germination of most of the weed seeds was completely arrested (0) at 32 dS m(-1) salinity except in E. colona (12%) and C. iria (13.9%). The species C. iria, E. colona, J. linifolia and E. crusgalli showed better germination (above 30%) upto 24 dS m(-1) salinity level and were regarded as salt-tolerant weed species. J. linifolia, F. miliacea, L. chinensis and O. sativa L. (weedy rice) were graded as moderately tolerant and S. zeylanica, S. grosus and C. difformis were regarded as least tolerant weed species.     

铬胁迫下不同品种小麦萌发和内源激素的变化

采用K2(CrO4)3溶液,设5个浓度,对3种不同抗性的小麦品种(新麦19、矮抗58和豫麦18)进行萌发期胁迫处理,研究了幼苗的发芽势、发芽率、根长、芽长及内源激素含量的变化.结果表明:(1)随着铬浓度的增加,发芽势、发芽率和芽长均基本呈"先升后降"趋势;(2)同一浓度铬处理下,发芽率、发芽势和芽长从大到小的顺序依次为:新麦19、矮抗58、豫麦18,根长从大到小的顺序为:豫麦18、新麦19、矮抗58;(3)150 mg L-1的铬胁迫下,IAA与ABA在小麦幼苗、幼根中含量降低,在籽粒中含量升高,其中新麦19籽粒和根芽中ABA含量均高于其他品种的;(4)不同浓度铬胁迫下,IAA/ABA值在新麦19中最低,变化幅度最小,新麦19表现出较强的抵抗铬胁迫能力.图3表1参20     

On the relative contributions of wind vs. animals to seed dispersal of four Sierra Nevada pines

Selective pressures that influence the form of seed dispersal syndromes are poorly understood. Morphology of plant propagules is often used to infer the means of dispersal, but morphology can be misleading. Several species of pines, for example, have winged seeds adapted for wind dispersal but owe much of their establishment to scatter-hoarding animals. Here the relative importance of wind vs. animal dispersal is assessed for four species of pines of the eastern Sierra Nevada that have winged seeds but differed in seed size: lodgepole pine (Pinus contorta murrayana, 8 mg); ponderosa pine (Pinus ponderosa ponderosa, 56 mg); Jeffrey pine (Pinus jeffreyi, 160 mg); and sugar pine (Pinus lambertiana, 231 mg). Pre-dispersal seed mortality eliminated much of the ponderosa pine seed crop (66%), but had much less effect on Jeffrey pine (32% of seeds destroyed), lodgepole pine (29%), and sugar pine (7%). When cones opened most filled seeds were dispersed by wind. Animals removed > 99% of wind-dispersed Jeffrey and sugar pine seeds from the ground within 60 days, but animals gathered only 93% of lodgepole pine seeds and 38% of ponderosa pine seeds during the same period. Animals gathered and scatter hoarded radioactively labeled ponderosa, Jeffrey, and sugar pine seeds, making a total of 2103 caches over three years of study. Only three lodgepole pine caches were found. Caches typically contained 1-4 seeds buried 5-20 mm deep, depths suitable for seedling emergence. Although Jeffrey and sugar pine seeds are initially wind dispersed, nearly all seedlings arise from animal caches. Lodgepole pine is almost exclusively wind dispersed, with animals acting as seed predators. Animals treated ponderosa pine in an intermediate fashion. Two-phased dispersal of large, winged pine seeds appears adaptive; initial wind dispersal helps to minimize pre-dispersal seed mortality whereas scatter hoarding by animals places seeds in sites with a higher probability of seedling establishment.     

生物炭早期植物毒性评估培养方法研究

为更加科学地评估生物炭潜在植物毒性,采用生物炭(B)、生物炭+土壤(B+S)、生物炭水浸提液+土壤(AE+S)、生物炭+石英砂(B+Q)、生物炭水浸提液+石英砂(AE+Q)5种不同的培养方法进行早期植物毒性效应实验。比较分析不同培养方法中西红柿种子发芽率、根长、芽长对生物炭的响应。结果表明:在5种培养方法中,随生物炭剂量增加,西红柿种子发芽率、根长、芽长呈现先增后降的变化趋势。虽在低剂量生物炭处理下(10.0 g·kg~(-1)),种子萌发表现出促进作用。但随剂量增加,除B+S和AE+S外,均表现出一定的抑制作用,且当剂量为160.0 g·kg~(-1)时,抑制作用达到最大。对比有土和无土培养方法中种子萌发情况发现,在高剂量下,无土培养方法中种子发芽率,根、芽生长所受抑制作用显著高于有土培养方法。无土方法中,尤其AE+Q方法中,高剂量生物炭对种子发芽率、根长、芽长表现出最大的抑制作用,其中发芽率抑制率为91.1%,根长抑制率为77.7%,芽长抑制率为93.7%。综合比较分析,生物炭水浸提液+石英砂(AE+Q)的培养方法干扰因子少,可提高毒性响应灵敏度。因此,在生物炭早期植物毒性效应评估中,该法可作为推荐的培养方法。     

Effect of Pseudomonas fluorescens on metal phytoextraction from contaminated soil by Brassica juncea

The present study deals with metal uptake by Brassica juncea in the presence of Pseudomonas fluorescens Pf 27 for Zn, Cu and Cd removal from brass and electroplating-industry effluent-contaminated soil. Inoculation of P. fluorescens significantly (p<0.05) increased water soluble (Ws) and exchangeable (Ex) metal content in contaminated soil in laboratory conditions and also enhanced plant biomass by 99% and chlorophyll content by 91% as compared to uninoculated plants in the greenhouse. The metal uptake by B. juncea followed the pattern Zn>Cu>Cd and increased with increasing plant growth duration. P. fluorescens inoculation increased root and shoot uptake of Zn by 3.05 and 2.69, Cu by 3.19 and 2.82 and Cd by 3.11- and 2.75-fold, respectively. BCF value for each metal was>1 and increased by 44%, 42% and 38% for Zn, Cu and Cd, respectively, in inoculated conditions, whereas TF remained unaffected and followed the order Zn>Cd>Cu. P. fluorescens inoculation also enhanced Ws fraction of Zn, Cu and Cd by 99%, 77% and 90% and Ex by 107%, 70% and 93%, respectively. Results depicted that association of B. juncea with P. fluorescens could be a promising strategy for enhancing soil metal bioavailability and plant growth for successful phytoremediation of heavy metal contaminated soils.     

生物炭对小麦种子萌发与幼苗生长的植物毒理效应

为明确生物炭对植物的毒性效应,以石英砂+生物炭水浸提液培养方法研究不同剂量生物炭对小麦种子萌发与幼苗生长的影响。结果表明:在不同剂量(0.0、10.0、20.0、40.0、80.0、160.0 g·kg~(-1))生物炭水浸提液处理下,虽然小麦发芽率较对照组无显著性变化(P0.05),但根、芽生长表现出低剂量促进高剂量抑制,且在160.0 g·kg~(-1)时抑制率最大,分别为18.11%和22.22%。在幼苗的生长期(11 d),高剂量生物炭对幼苗根生长的抑制作用增强,160.0 g·kg~(-1)处理下抑制率显著增加至55.59%(P0.05)。此外,当生物炭剂量较低时,小麦幼苗根、叶中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活力增加;随生物炭剂量的增加,3种抗氧化酶活力降低,丙二醛(MDA)含量升高,幼苗生长出现生理损伤,表现出明显植物毒性效应。     

青岛市城市绿地种子植物区系的构成特征

在资料分析和2013年夏秋二季进行的实地调查基础上研究了青岛市城市绿地种子植物区系的科属种构成、种的生活型构成、属的地理分布区类型构成,并比较了青岛市城市绿地种子植物区系与青岛崂山种子植物区系、中国种子植物区系属的地理分布区类型构成差异。结果表明,青岛市城市绿地种子植物区系有种子植物69科155属228种,有含5种及以上的12个较大科、124个单种属、183种木本植物和45种草本植物,有热带分布属32属、温带分布属95属、世界分布属14属和中国特有属14属。青岛市城市绿地种子植物区系有植物种类丰富多样,木本植物种类多,区系中属、种的分化程度高,属的地理分布区类型多样且具有很典型的温带特征和鲜明的中国特色等特点。     

硅促进水稻种子萌发及缓解幼苗砷毒性的效应研究

通过As~(Ⅲ)胁迫下水稻种子的发芽试验和幼苗毒性试验,研究了外源硅对水稻种子发芽率、幼苗生长的影响及其缓解幼苗砷毒性的效应。外源硅的2种处理方式为种子萌发时添加外源硅(Si1)和采用硅处理液浸种(Si2)。结果表明,发芽时介质中As浓度达到10 mg·L~(-1)时显著抑制水稻种子萌发(P0.05),发芽率仅为80%,但是Si1和Si2处理下发芽率则提高到97%和100%,这说明外源硅可促进砷胁迫下水稻种子萌发;砷浓度≥5 mg·L~(-1)时,Si1和Si2处理均可提高水稻的相对幼苗高度和根耐性指数,提高幅度分别为6.00%~16.8%和57.9%~77.0%、7.10%~23.5%和54.2%~61.2%,并且降低了水稻幼苗砷含量,降低幅度分别为17.8%~21.4%和31.0%~49.1%。这说明外源硅处理可促进砷胁迫下水稻幼苗的生长;不同砷浓度处理与水稻芽长、根长及幼苗干重之间存在"S"型的剂量-效应关系,且外源硅显著提高了相应的EC50,缓解了砷对水稻幼苗生长的毒性。综上所述,砷胁迫下水稻种子萌发时添加外源硅或采用硅处理液浸种均可促进水稻种子萌发和幼苗生长,并降低了幼苗砷累积和缓解砷对水稻幼苗的毒性。     

Biotic resistance via granivory: establishment by invasive, naturalized, and native asters reflects generalist preference

Escape from specialist natural enemies is frequently invoked to explain exotic plant invasions, but little attention has been paid to how generalist consumers in the recipient range may influence invasion. We examined how seed preferences of the widespread generalist granivore Peromyscus maniculatus related to recruitment of the strongly invasive exotic Centaurea stoebe and several weakly invasive exotics and natives by conducting laboratory feeding trials and seed addition experiments in the field. Laboratory feeding trials showed that P. maniculatus avoided consuming seeds of C. stoebe relative to the 12 other species tested, even when seeds of alternative species were 53-94% smaller than those of C. stoebe. Seed addition experiments conducted in and out of rodent exclosures revealed that weakly invasive exotics experienced relatively greater release from seed predation than C. stoebe, although this was not the case for natives. Seed mass explained 81% of the variation in recruitment associated with rodent exclusion for natives and weak invaders, with larger-seeded species benefiting most from protection from granivores. However, recruitment of C. stoebe was unaffected by rodent exclusion, even though the regression model predicted seeds of correspondingly large mass should experience substantial predation. These combined laboratory and field results suggest that generalist granivores can be an important biological filter in plant communities and that species-specific seed attributes that determine seed predation may help to explain variation in native plant recruitment and the success of exotic species invasions.     

Effect of arbuscular mycorrhizal (AM) fungus and plant growth promoting rhizomicroorganisms (PGPR's) on medicinal plant Solanum viarum seedlings

A green house nursery study was conducted to assess the interaction between arbuscular mycorrhizal (AM) fungus, Glomus aggregatum and some plant growth promoting rhizomicrooganisms (PGPR's), Bacillus coagulans and Trichoderma harzianum, in soil and their consequent effect on growth, nutrition and content of secondary metabolities of Solanum viarum seedlings. Triple inoculation of G. aggregatum+B. coagulans+T. harzainum with Solanum viarum in a green house nursery study resulted in maximum plant biomass (plant height 105 cm and plant dry weight 12.17 g), P, Fe, Zn, Cu and Mn and secondary metabolities [total phenols (129.6 microg g(-1) f.wt.), orthodihydroxy phenols (90.6 microg g(-1) f.wt.), flavonoids (3.94 microg g(-1) f.wt.), alkaloids (5.05 microg g(-1) f.wt.), saponins (5.05 microg g(-1) f.wt.) and tannins (0.324 microg g(-1) f.wt.)] of S. viarum seedlings. The mycorrhizal root colonization and spore numbers in the root zone soil of the inoculated plants increased. The enzyme activity namely acid phosphatase (53.44 microg PNP g(-1) soil), alkaline phosphatase (40.95 microg PNP g(-1) soil) and dehydrogenase (475.5 microg PNP g(-1) soil) and total population of B. coagulans (12.5x10(4) g(-1)) and T. harzianum (12.4 x 10(4) g(-1)), in the root zone soil was found high in the triple inoculation with G. aggregatum+B. coagulans+T. harzianum that proved to be the best microbial consortium.     

镉在北京褐潮土中对玉米幼苗及其根际微生物的毒性效应

通过温室盆栽实验,研究了镉在北京褐潮土中对玉米(品种郑单958)幼苗的毒性效应及其生物富集特性,并通过聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术,探讨了镉对玉米根际微生物群落结构的影响。结果表明,高浓度(>100mg·kg-1)镉对玉米幼苗的生长发育有明显的抑制作用,北京褐潮土中镉引起玉米幼苗株高下降1/2的效应浓度(EC50)为654.6mg·kg-1,引起玉米根部和地上部干质量下降1/2的EC50分别为323.6和110.2mg·kg-1,玉米幼苗地上部生物量(干质量)可作为评价重金属生态毒性的适宜终点。玉米幼苗对镉有一定的吸收累积效应,镉在玉米幼苗各组织中的浓度分布为根>茎>叶,其中根部对镉有一定的富集作用(生物富集系数BAF>1)。镉污染可引起玉米根际微生物群落结构发生改变,高浓度(1000mg·kg-1)镉可导致部分微生物种群数量减少甚至完全消失,表明镉污染可对植物幼苗、植物根际微生物以及植物-微生物之间的相互作用造成重要的干扰和威胁。     

Detoxification of 4-chlorophenol in TiO2 sunlight system: effect of raw and treated solution on seed germination and plants growth of various sensitive vegetables

The mineralization and detoxification of 4-chlorophenol (4-CP) were studied using a TiO₂-paper/sunlight system. The possibility of reusing the photocatalyst was examined to determine the cost effectiveness of the method. Experiments were performed to establish optimum conditions for 4-CP removal. Phytotoxicity of photo-treated and raw 4-CP (100 mg L^?1) solutions on seed germination and plant growth were carried out with the aim of water reuse and environment protection. The seeds irrigated with raw 4-CP solution showed lower sprout length while increase in sprout length was observed with the photo-treated solution for tomato (Lycopersicon esculentum), lettuce (Lactuca sativa), onion (Allium cepa), and turnip (Brassica rapa). Plant growth tests with the photo-treated 4-CP solution did not affect the leaf numbers compared to those irrigated with tap water. Photo-treated 4-CP solution can be used for irrigation in agriculture.     

Comparison of growth performance of Lolium perenne L., Dactylis glomerata L. and Agropyron elongatum (Host.) P. Beauv. for erosion control in Turkey

This study was carried out in plastic containers to compare growth performances of perennial ryegrass, orchardgrass and tall wheatgrass to be given priority in revegetation studies in Turkey. Three pre-germinated seeds of each grass species were planted separately into the soil in the black plastic containers. Seedlings were harvested 2, 4 and 6 months after planting pre-germinated seeds and measured for percentage of seedling emergence, rooting depth, height growth, leaf and tiller development and shoot and root weights. Germination percentage was 97.8% for perennial ryegrass, 64.1% for orchardgrass and 11.6% for tall wheatgrass and perennial ryegrass had the greatest whereas tall wheatgrass had the lowest seedling emergence. Two months old rooting depth was 25.66 cm for perennial ryegrass, 20.56 cm for orchardgrass and 30.10 cm for tall wheatgrass. At the end of the study, perennial ryegrass developed about 104 tillers per plant while they were 21.4 and 36.6 tillers per plant for orchardgrass and tall wheatgrass, respectively. Orchardgrass produced greater shoot and root biomasses than tall wheatgrass and similar to perennial ryegrass. All these meant that perennial ryegrass had a better growth performance than orchardgrass and tall wheatgrass to be used for erosion control.     

Screening of wheat varieties and associated bacterial population in old alluvial soil of Burdwan, West Bengal

In order to screen out the best variety of wheat (Triticum aestivum) out of eight varieties (viz., HP 1633, BW 11, NW 1014, Sonalika, HUW 468, K 9107, HP 1731 and HUW 234), a field experiment was conducted (from Dec. 2002 to April 2003) in a randomized block design replicated thrice at Crop Research and Seed Multiplication Farm, Burdwan University, West Bengal, India. Various morpho physiological parameters viz., plant population, length of shoot and root, leaf area index (LAI), crop growth rate (CGR), leaf area ratio (LAR), leaf area duration (LAD), net assimilation rate (NAR), yield attributes viz., length of panicles, number of grains per panicle, grain yield, straw yield, pigment content in flag leaf (chlorophyll a, b and total chlorophyll and carotenoid content) were estimated and analyzed statistically Soil bacterial populations were also estimated in the fallow land before sowing of seeds and after harvesting of crop. The HUW 468 variety records higher grain yield, maximum panicle length and maximum chlorophyll b and total chlorophyll content.     

3种抗生素对黑麦草种子萌发的生态毒性效应

为探明四环素、环丙沙星和磺胺嘧啶3种抗生素对黑麦草种子萌发的影响,为评价抗生素污染的生态影响提供科学依据,采用保湿培养法研究了它们对黑麦草种子萌发的影响,比较分析了抗生素的生态毒性差异和相对敏感的指标。结果表明,在种子萌发期,一定浓度范围的抗生素胁迫会引发植物种子抵抗逆境的应激反应,因此,3种抗生素在1 mg·L~(-1)处理水平下均能促进种子发芽。超过该浓度,四环素对黑麦草种子发芽仍有一定的促进作用,而环丙沙星和磺胺嘧啶则表现为抑制作用。四环素对种子发芽率的最大无作用浓度(NOEC)为5 mg·L~(-1),而环丙沙星和磺胺嘧啶对种子发芽率的NOEC为1 mg·L~(-1)。实验结束时,3种抗生素在1 mg·L~(-1)处理水平下的种子发芽率最高。3种抗生素浓度超过0.1 mg·L~(-1)时,种子根长和芽长即受到抑制,因此,它们对种子根长和芽长的NOEC均为0～0.1 mg·L~(-1)。其中,磺胺嘧啶的抑制作用最为显著。根长受到抑制的程度强于芽长。黑麦草种子萌发受3种抗生素影响程度依次为磺胺嘧啶环丙沙星四环素。