Rhizosphere colonization and seedling growth promotion of lodgepole pine by Bacillus polymyxa

1992 ◽  
Vol 38 (4) ◽  
pp. 303-308 ◽  
Author(s):  
F. B. Holl ◽  
C. P. Chanway
Keyword(s):  
Seedling Growth ◽  
Shoot Growth ◽  
Growth Promotion ◽  
Lodgepole Pine ◽  
Dry Weight ◽  
Root Tissue ◽  
Bacillus Polymyxa ◽  
Rhizosphere Colonization ◽  
Order Of Magnitude ◽  
Rhizosphere Population

Lodgepole pine seed was inoculated with Bacillus polymyxa isolate L6-16R, a strain marked with antibiotic resistance to 100 mg rifamycin per litre. Inoculation resulted in statistically significant seedling biomass increases after 8 weeks of pine growth. The L6-16R rhizosphere population declined by an order of magnitude per month, from ca. 106 cfu/g dry weight of pine root tissue 4 weeks past inoculation to ca. 104 cfu/g of root tissue 12 weeks past inoculation. Seed-lings from three of four pine provenances had mean shoot and root dry weight increases of up to 35% due to seed inoculation, but shoot growth of the fourth provenance was inhibited. The size of the L6-16R rhizosphere population was not correlated to the magnitude of the shoot growth response 4 weeks after inoculation, but it showed a strong correlation with shoot growth 8 weeks after inoculation. These results indicate that the promotion of pine seedling growth may be a function of the size of the bacterial rhizosphere population that develops 4 weeks after inoculation, and that B. polymyxa may promote growth of lodgepole pine collected from many, but not all provenances. Key words: Bacillus polymyxa, lodgepole pine, growth promotion, rhizosphere colonization.

N2-Fixation and Seedling Growth Promotion of Lodgepole Pine by Endophytic Paenibacillus polymyxa

2013 ◽  
Vol 66 (2) ◽  
pp. 369-374 ◽  
Author(s):  
Richa Anand ◽  
Susan Grayston ◽  
Christopher Chanway
Keyword(s):  
Seedling Growth ◽  
N2 Fixation ◽  
Growth Promotion ◽  
Lodgepole Pine ◽  
Paenibacillus Polymyxa

scholarly journals Enhancing the 1-Aminocyclopropane-1-Carboxylate Metabolic Rate of Pseudomonas sp. UW4 Intensifies Chemotactic Rhizocompetence

2020 ◽  
Vol 8 (1) ◽  
pp. 71
Author(s):  
Xiyang Gao ◽  
Tao Li ◽  
Wenliang Liu ◽  
Yan Zhang ◽  
Di Shang ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Growth Promotion ◽  
Gene Promoter ◽  
Acc Deaminase ◽  
Dry Weight ◽  
Chemotactic Activity ◽  
Pseudomonas Sp ◽  
Rhizosphere Colonization ◽  
Synthetic Promoters ◽  
Acds Gene

1-aminocyclopropane-1-carboxylic acid (ACC) is a strong metabolism-dependent chemoattractant for the plant beneficial rhizobacterium Pseudomonas sp. UW4. It is unknown whether enhancing the metabolic rate of ACC can intensify the chemotaxis activity towards ACC and rhizocompetence. In this study, we selected four promoters to transcribe the UW4 ACC deaminase (AcdS) gene in the UW4 ΔAcdS mutant. PA is the UW4 AcdS gene promoter, PB20, PB10 and PB1 are synthetic promoters. The order of the AcdS gene expression level and AcdS activity of the four strains harboring the promoters were PB20 > PA > PB10 > PB1. Interestingly, the AcdS activity of the four strains and their parent strain UW4 was significantly positively correlated with their chemotactic activity towards ACC, rhizosphere colonization, roots elongation and dry weight promotion. The results released that enhancing the AcdS activity of PGPRenable them to achieve strong chemotactic responses to ACC, rhizocompetence and plant growth promotion.

The growth of lodgepole pine seedlings raised under clear polythene cloches at five seedbed densities

1980 ◽  
Vol 10 (3) ◽  
pp. 426-428
Author(s):  
S. Thompson
Keyword(s):  
Plant Height ◽  
Dry Matter ◽  
Shoot Growth ◽  
Lodgepole Pine ◽  
Unit Length ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Matter Production ◽  
Pine Seedlings ◽  
Foliage Weight

The components of shoot growth and dry matter production in 1 + 0 lodgepole pine (Pinuscontorta Dougl. ex Loud. spp. contorta) seedlings raised under clear polythene cloches for 12 weeks at five seedbed densities (180–720 plants/m2) were studied. The greater plant height found at the highest seedbed density was the result of increased stem unit length, not increased number of stem units. The increase in plant dry weight as seedbed density decreased was largely due to greater dry weight of roots, branchwood, and branch foliage, and not to increases in stemwood and stem foliage weight. Seedbed densities of less than 460 seedlings/m2 are required to produce yields of suitably sturdy seedlings in excess of 50% of the crop.

The growth-promoting effects of a bacterial endophyte on lodgepole pine are partially inhibited by the presence of other rhizobacteria

1998 ◽  
Vol 44 (10) ◽  
pp. 980-988 ◽  
Author(s):  
Elizabeth Bent ◽  
Christopher P Chanway
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Lodgepole Pine ◽  
Primary Root ◽  
Biomass Accumulation ◽  
Plant Growth Promoting Rhizobacteria ◽  
Shoot Biomass ◽  
Bacillus Polymyxa ◽  
Plant Growth Promoting ◽  
Growth Promoting

To test the hypothesis that rhizobacteria naturally present in soils may interfere with the extent of root colonization and plant growth promotion by plant growth-promoting rhizobacteria (PGPR), we studied two lodgepole pine PGPR (Bacillus polymyxa strains L6 and Pw-2) when inoculated singly and when coinoculated with a non-PGPR competitor (Curtobacterium flaccumfaciens PF322). Bacillus polymyxa Pw-2 and Curtobacterium flaccumfaciens PF322 were consistently found as endophytes, while Bacillus polymyxa L6 was never found within the root interior. Strains Pw-2 and L6 differed in the rate and type of growth promotion. Strain Pw-2 increased root growth (branching and elongation) and shoot biomass accumulation 6 and 9 weeks, respectively, after inoculation, while strain L6 increased primary root elongation and root biomass accumulation after 12 weeks. Seedlings coinoculated with Pw-2 and PF322 had decreased shoot biomass and primary root lengths when compared with seedlings inoculated only with Pw-2. This effect was not linked to a decrease in the population size of Pw-2 in the rhizosphere or in the root interior of coinoculated treatments. In contrast, strain L6-mediated growth promotion was not impaired by coinoculation with PF322. Strain L6 did interfere to some degree with the growth-promoting capability of strain Pw-2. These results indicate that endophytic PGPR may be less adapted to microbial competition than external root-colonizing PGPR, and that the efficacy of endophytic PGPR may be reduced by the presence of other bacteria on external or internal root tissues.Key words: PGPR, endophytes, colonization, coinoculation, competition.

Trifluralin and Triallate Retention by Imbibed Tame Oat (Avena sativa) Caryopses

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Martin C. Heath ◽  
Ross Ashford ◽  
Robert B. McKercher
Keyword(s):  
Seedling Growth ◽  
Avena Sativa ◽  
Shoot Growth ◽  
Residual Activity ◽  
Dry Weight ◽  
Distilled Water ◽  
Coleoptile Length ◽  
Seed Imbibition ◽  
Shoot Dry Weight ◽  
Phytotoxic Effect

The effect of exposing tame oat (Avena sativaL. ‘Hudson’) to trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate] during seed imbibition was investigated in a growth cabinet at 21 C in the absence of light. Caryopses were imbibed in 0.0, 1.5, and 3.0 ppmv aqueous dilutions of trifluralin and triallate for up to 10 h, after which germination was continued in distilled water. Germination was not affected following imbibition in either herbicide. Both herbicides produced distinct visual symptoms of herbicide injury during subsequent seedling growth. Coleoptile length of 5-day-old seedlings was reduced following imbibition in a 1.5-ppmv dilution of either herbicide. Triallate at 1.5 ppmv resulted in a reduction in shoot dry weight. Both herbicides were largely excluded from embryos of imbibing caryopses. Seedlings were unaffected when cultured from embryos excised from caryopses imbibed in trifluralin and triallate dilutions. Seedling phytotoxic effects resulted from residual activity of trifluralin and triallate retained by the pericarp and testa of imbibed caryopses. Presence of the hull during imbibition decreased the phytotoxic effect of both herbicides on shoot growth. These findings suggest that germinating seedlings ofAvenaspp. may be affected by trifluralin and triallate at an earlier stage than previously realized.

Biological nitrogen fixation and plant growth promotion of lodgepole pine by an endophytic diazotroph Paenibacillus polymyxa and its GFP-tagged derivative

Botany ◽  
2017 ◽  
Vol 95 (6) ◽  
pp. 611-619 ◽  
Author(s):  
Qian Tang ◽  
Akshit Puri ◽  
Kiran Preet Padda ◽  
Chris P. Chanway
Keyword(s):  
Plant Growth ◽  
Seedling Growth ◽  
Fluorescent Protein ◽  
Growth Promotion ◽  
Lodgepole Pine ◽  
Paenibacillus Polymyxa ◽  
Growth Enhancement ◽  
Plant Growth Promoting ◽  
Green Fluorescent ◽  
Biological Nitrogen

Paenibacillus polymyxa P2b-2R is an endophytic diazotroph originally isolated from lodgepole pine. It is reported to fix significant amounts of nitrogen (N) and promote plant growth. To evaluate the endophytic colonization sites, a green fluorescent protein (GFP) derivative of P2b-2R was generated (P2b–2Rgfp), but the effects of GFP modification on the functioning of P2b-2R have not been fully elucidated yet. In this study, we wanted to confirm and contrast the N-fixing and plant-growth-promoting abilities of P2b-2Rgfp with those of the wild-type P2b-2R in lodgepole pine. Pine seedlings were grown in an N-limited environment and harvested 2, 4, 8, and 12 months after inoculation to evaluate the endophytic and rhizospheric colonization by both strains, the amount of N-fixed, and seedling growth enhancement. Both P2b-2R and P2b-2Rgfp strains formed persistent rhizospheric and endophytic populations; fixed N; and enhanced seedling growth continuously after 4 months. P2b-2Rgfp-treated seedlings outperformed the P2b-2R-treated seedlings in terms of biomass only during the initial stages of plant development, but the differences decreased during the trial and were not significant towards the end. To the best of our knowledge, this is the first study that reports the effects of GFP-tagging of an endophyte when inoculated into a gymnosperm tree species.

scholarly journals Germination, Emergence, and Seedling Growth of Tomato and Impatiens in Response to Seed Treatment with Paclobutrazol

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1201-1204 ◽  
Author(s):  
Jennifer R. Still ◽  
Wallace G. Pill
Keyword(s):  
Seedling Growth ◽  
Seed Treatment ◽  
Shoot Growth ◽  
Dry Weight ◽  
Suppressive Effect ◽  
Growth Suppression ◽  
Growth Retardant ◽  
Lower Percentage ◽  
Shoot Height ◽  
Grade 5

Seed treatments with paclobutrazol (PB), a triazole growth retardant, were examined for seedling growth suppression without exerting a deleterious effect on germination or emergence. Seeds of `Salmon Picotee impatiens (Impatiens wallerana Hook f.) and `Marglobe tomato (Lycopersicon esculentum Mill.) were soaked for 24 or 48 hours at 22 °C in 0, 50, 500, or 1000 mg·L-1 PB or were primed in polyethylene glycol 8000 or grade 5 exfoliated vermiculite (both at -1.0 MPa for 7 days at 22 °C) containing these PB solutions. Any PB seed treatment of impatiens (including a series of lower concentrations up to 50 mg·L-1 PB) that elicited seedling growth suppression also reduced germination and emergence. For tomato, soaking seeds for 24 hours in up to 1000 mg·L-1 PB had little or no effect on germination or emergence, and yet shoot height or dry weight was not decreased further by exceeding 50 mg·L-1 PB. At any PB concentration, soaking seeds for 48 hours or priming seeds resulted in lower percentage of germination or emergence than soaking seeds for 24 hours. Soaking tomato seeds in 50 mg·L-1 PB for 24 hours resulted in similar shoot growth suppression until at least 31 days after planting as a growth medium drench (1 mg·L-1 PB) or as a shoot spray (10 mg·L-1 PB), both applied at 14 days after planting. Beyond 31 days after planting, however, the latter two treatments gave greater shoot growth suppression than the PB seed soak treatment, which had lost its growth suppressive effect. Chemical name used: (+)-(R*,R*)-[(4-chlorophenyl)methyl]- -(1,1,-dimethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

IMPACT OF FERTILIZERS APPLICATION ON SEED GERMINATION AND SEEDLING GROWTH OF VIGNA RADIATA

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
SUPRIYA DIXIT ◽  
R. K. GUPTA
Keyword(s):  
Seed Germination ◽  
Leaf Area ◽  
Seedling Growth ◽  
Vigna Radiata ◽  
Agricultural Research ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Research Field ◽  
Chemical Fertilizer ◽  
Seedling Length

Currently, a real challenge for the workers in the agricultural research field is to stop or reduce the use of expensive agrochemicals/ chemical fertilizers which are hazardous to the environment as well as human health. Present study was aimed to improve the growth and obtain optimum yield of Vigna crop with eco-friendly, non-toxic way and to reduce the use of agrochemical/chemical fertilizer application in agricultural activities. A pot experiment was conducted to study the effect of chemical fertilizer (DAP) and biofertilizer ( Rhizobium strain) separately and in combination on seed germination and seedling growth (at 30 days) based on morphological parameters such as seedling length (cm), fresh weight (g), dry weight (g) and leaf area (cm)2 of Vigna radiata (L.) Wilczek. After one month (30 Days) observations, it was found that seedling length, fresh and dry weights and leaf area were maximum in T4 and minimum in T15, T7 and T8 favored improved seedling length and leaf area whereas T7, T8, and T9 favored improved fresh and dry weights as compared to control.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

Salinity Tolerance of Black Gram Cultivars During Germination and Early Seedling Growth

2018 ◽  
Vol 51 (3) ◽  
pp. 51-68 ◽  
Author(s):  
M.K. Hasan ◽  
M.S. Islam ◽  
M.R. Islam ◽  
H.N. Ismaan ◽  
A. El Sabagh
Keyword(s):  
Salt Stress ◽  
Salinity Tolerance ◽  
Seedling Growth ◽  
Negative Impact ◽  
Germination Rate ◽  
Dry Weight ◽  
Germination Percentage ◽  
Shoot Length ◽  
Sand Culture ◽  
Black Gram

Abstract A laboratory experiment regarding germination and seedling growth test was conducted with three black gram genotypes tested under three salinity levels (0, 75 and 150 mM), for 10 days, in sand culture within small plastic pot, to investigate the germination and seedling growth characteristics. Different germination traits of all black gram genotypes, like germination percentage (GP), germination rate (GR), coefficient of velocity of germination (CVG) greatly reduced, as well as mean germination time (MGT) increased with increasing salt stress. At high salt stress, BARI Mash-3 provided the highest GP reduction (28.58%), while the lowest was recorded (15.79% to control) in BARI Mash-1. Salinity have the negative impact on shoot and root lengths, fresh and dry weights. The highest (50.32% to control) and lowest reduction (36.39%) of shoot length were recorded in BARI Mash-2 and BARI Mash-1, respectively, under 150 mM NaCl saline conditions. There were significant reduction of root lengths, root fresh and dry weight, shoot length, shoot fresh and dry weight in all genotypes under saline condition. The genotypes were arranged as BARI Mash-1 > BARI Mash-3 > BARI Mash-2, with respect to salinity tolerance.

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