scholarly journals Increased Flower Production of Calibrachoa x hybrida by the Soil Fungus Mortierella elongata1

2020 ◽  
Vol 38 (4) ◽  
pp. 114-119
Author(s):  
Lindsey E. Becker ◽  
Marc A. Cubeta

Abstract Calibrachoa (Calibrachoa x hybrida) is a highly valued solanaceous flowering ornamental plant, characterized by its drought-hardiness, abundant flowering, and diverse flower colors. Recently, the saprobic soil fungus Mortierella elongata was isolated as a root endophyte from eastern cottonwood (Populus deltoides) and identified as a potential biological amendment for bioenergy and food crops. Two greenhouse experiments were conducted by transplanting rooted cuttings of Calibrachoa cv. ‘Kabloom Deep Blue' into a potting media mixture amended with 1 or 2% volume mix ratio of millet seed colonized with one of four isolates of M. elongata. Plants were assessed weekly for flower production and 86 days post inoculation for leaf/stem, root, and total dry weight. M. elongata strain 624- significantly increased flower production compared to the non-inoculated millet seed controls at 6 and 7 wk post amendment in both experiments. Above and below ground vegetative dry weight for plants grown in potting media mixture amended with M. elongata isolates varied across isolates, fungal amendment concentrations, and experiments. Our results suggest that potting media mixture amended with M. elongata strain 624- can increase flower production of Calibrachoa during peak marketable periods. Index words: Calibrachoa, plant growth promotion, plant reproduction, biological amendment. Species used in this study: Calibrachoa (Calibrachoa x hybrida); Mortierella elongata Linnem.

2021 ◽  
Vol 24 (2) ◽  
pp. 121-124
Author(s):  
SMN Islam ◽  
MZH Chowdhury ◽  
NJ Mishu

Application of phosphorus solubilizing microbes is a promising tool for enhancing P uptake in plant. The aim of this study was to evaluate the phosphate solubilization potential and growth promotion of pea (Pisum sativum L.) by native Trichoderma asperellum isolate G3. Phosphate solubilization by T. asperellum strain was assessed in National Botanical Research Institute’s Phosphate (NBRIP) broth medium. Pea plants were inoculated by Trichoderma strain and grown in pot in phosphate deficit condition. The fungal strain was able to solubilize phosphate (from 188.95±2.04 to 262.50±3.80 mgL-1) in broth at different time periods and decreased solution pH. The Trichoderma inoculated pea plant increased the root growth, shoot growth, leaf number, shoot biomass, root biomass, total dry weight, chlorophyll a, chlorophyll b and carotenoid by 23.9%, 33.3%, 33%, 37.1%, 32.7%, 28.4%, 24.5%, 17.4% and 14.7% respectively over control after 5 weeks of post inoculation. The results showed that the native T. asperellum isolate G3 has great potential in the phosphorus solubilization. Ann. Bangladesh Agric. (2020) 24(2) : 121-124


Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1404-1414 ◽  
Author(s):  
T. B. Enzenbacher ◽  
M. K. Hausbeck

Cucumber (Cucumis sativus) and squash (Cucurbita spp.) production in Michigan is limited by the oomycete pathogen Phytophthora capsici. Cucumber, summer squash, and winter squash fruit were evaluated for susceptibility to five isolates of P. capsici. Detached fruit were inoculated with a 5-mm-diameter culture plug of mycelia and sporangia and were incubated in a laboratory or greenhouse. Lesion and pathogen growth diameters were measured and pathogen growth density was visually assessed. All P. capsici isolates incited rot, with significant differences found among fruit type and pathogen isolate. Straightneck squash (Cucurbita pepo), slicing cucumber, and butternut squash (C. moschata) exhibited more severe symptoms than the other fruit tested. Summer and winter squash seedlings were evaluated in greenhouse experiments, in which P. capsici-infested millet seed (approximately 1 g) were placed on the surface of soilless potting media. Disease severity was visually assessed every 2 days for 14 days post inoculation. Crop type, pathogen isolate, or the crop type–pathogen isolate interaction term were significant for symptom appearance and area under the disease progress curve values. Differences in susceptibility of butternut squash and zucchini cultivars were observed following inoculation with solanaceous isolate 13351. Results from this study can refine management programs for Phytophthora rot.


2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508b-508
Author(s):  
Pamela M. Lewis ◽  
Alan M. Armitage ◽  
Jim M. Garner

The effect of vernalization method and duration on off-season cut flower production of Lysimachia clethroides Duby was examined. Rhizomes harvested in October were cooled for 0, 4, 6, 8, 10 or 12 weeks at 4 ± 1 °C in crates with unmilled sphagnum peat or in 3.75-L pots with potting media prior to forcing in a warm greenhouse. After 6 or more weeks of cooling, shoots emerged from crate-cooled rhizomes in higher percentages than from pot-cooled rhizomes. However, only the duration of cooling, not the method, affected the rate of shoot emergence, visible bud formation and anthesis of the first bud in the raceme. As cooling increased from 0 to 12 weeks, the greenhouse days required for shoot emergence, visible bud formation and anthesis decreased linearly. The number of flowering flushes and flowering stems varied quadratically with cooling duration, and the highest yields occurred when rhizomes received between 4 and 10 weeks of cooling. As the number of successive flowering flushes increased, the stem length increased linearly while the stem diameter decreased linearly. High numbers of flowers were produced rapidly after 10 weeks of cooling.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Geetha Rajendran ◽  
Maheshwari H. Patel ◽  
Sanket J. Joshi

One of the ways to increase the competitive survivability of rhizobial biofertilizers and thus achieve better plant growth under such conditions is by modifying the rhizospheric environment or community by addition of nonrhizobial nodule-associated bacteria (NAB) that cause better nodulation and plant growth when coinoculated with rhizobia. A study was performed to investigate the most commonly associated nodule-associated bacteria and the rhizospheric microorganisms associated with theFenugreek(Trigonella foenum-graecum) plant. Isolation of nonrhizobial isolates from root nodules ofFenugreekwas carried out along with the rhizospheric isolates. About 64.7% isolates obtained fromFenugreeknodules were gram-negative coccobacilli, 29.41% were gram-positive bacilli, and all rhizospheric isolates except one were gram-positive bacilli. All the isolates were characterized for their plant growth promoting (PGP) activities. Two of the NAB isolates M2N2c and B1N2b (Exiguobacterium sp.) showed maximum positive PGP features. Those NAB isolates when coinoculated with rhizobial strain—S. meliloti, showed plant growth promotion with respect to increase in plant’s root and shoot length, chlorophyll content, nodulation efficiency, and nodule dry weight.


Pathogens ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 6 ◽  
Author(s):  
Sang-Jae Won ◽  
Jun-Hyeok Kwon ◽  
Dong-Hyun Kim ◽  
Young-Sang Ahn

This study investigated the control of foliar fungal diseases and growth promotion of Camellia oleifera seedlings in coastal reclaimed land through the use of Bacillus licheniformis MH48. B. licheniformis MH48 can produce lytic enzymes chitinase and β-1,3-glucanase that can inhibit foliar pathogens by 37.4 to 50.5%. Nevertheless, foliar diseases appeared in the seedlings with bacterial inoculation, and their survival rate decreased because they were unable to withstand salt stress. However, B. licheniformis MH48 significantly increased the total nitrogen and phosphorus contents in the soils through fixing atmospheric nitrogen and solubilizing phosphorus. The growth of seedlings with bacterial inoculation increased, particularly in root dry weight, by 7.42 g plant−1, which was 1.7-fold greater than that of the control. B. licheniformis MH48 produces the phytohormone auxin, which potentially stimulates seedling root growth. C. oleifera seedlings significantly increased in total nitrogen content to 317.57 mg plant−1 and total phosphorus content to 46.86 mg plant−1. Our results revealed the effectiveness of B. licheniformis MH48 not only in the control of foliar fungal diseases but also in the growth promotion of C. oleifera seedlings in coastal lands.


2017 ◽  
Vol 66 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Jian Zhang ◽  
Peng Cheng Wang ◽  
Ling Fang ◽  
Qi-An Zhang ◽  
Cong Sheng Yan ◽  
...  

Phosphorus is a major essential macronutrient for plant growth, and most of the phosphorus in soil remains in insoluble form. Highly efficient phosphate-solubilizing bacteria can be used to increase phosphorus in the plant rhizosphere. In this study, 13 isolates were obtained from waste mushroom residues, which were composed of cotton seed hulls, corn cob, biogas residues, and wood flour. NBRIP solid medium was used for isolation according to the dissolved phosphorus halo. Eight isolates produced indole acetic acid (61.5%), and six isolates produced siderophores (46.2%). Three highest phosphate-dissolving bacterial isolates, namely, M01, M04, and M11, were evaluated for their beneficial effects on the early growth of tomato plants (Solanum lycopersicum L. Wanza 15). Strains M01, M04, and M11 significantly increased the shoot dry weight by 30.5%, 32.6%, and 26.2%, and root dry weight by 27.1%, 33.1%, and 25.6%, respectively. Based on 16S rRNA gene sequence comparisons and phylogenetic positions, strains M01 and M04 belonged to the genus Acinetobacter, and strain M11 belonged to the genus Ochrobactrum. The findings suggest that waste mushroom residues are a potential resource of plant growth-promoting bacteria exhibiting satisfactory phosphate-solubilizing for sustainable agriculture.


Author(s):  
N. Kiran Kumar ◽  
P. Nagamani ◽  
K. Viswanath ◽  
L. Prasanthi

Background: The plant growth promotion and efficacy against phytopathogens by the endophytic bacteria are being focused now due to their ecofriendly nature. Methods: Endophytic bacteria (24 nos) isolated from the roots, stems and leaves of black gram plants collected from different locations were tested for their potential to inhibit the growth of R. bataticola under in vitro and in vivo conditions. Result: The leaf endophyte BLE 4 exhibited maximum inhibition (79.6%) of R. bataticola followed by BSE 4 (77.4%), BSE 7 (77.0%) and BLE 1 (74.0%). Among these 4 isolates tested as seed treatment and soil application, there was significant increase in dry weight (7.1 g), plant height (37.7 cm), number of branches (13.2) and number of pods (26.2) in BLE 4 treated plots. Whereas, the incidence of dry root rot and yield were insignificant. In the screening study of isolates for their phosphate solubilization potential, protease activity, siderophore and HCN production, no single isolate possessed all the properties, but siderophore production, protease activity and phosphate solubilization were found in BSE 4, BRE 3, BRE 5 and BRE 10 isolates. 


1958 ◽  
Vol 36 (1) ◽  
pp. 45-49
Author(s):  
S. Fedoroff ◽  
R. Altschul

In an attempt to elucidate the increase of growth promotion of tissue cultures by extracts obtained from tissues chilled before extraction, determinations of nitrogen content were made on (a) fresh, and chilled chick embryos, (b) extracts prepared from fresh and chilled chick embryos, (c) fresh and chilled human placenta, (d) extracts prepared from fresh and chilled human placenta.There was no difference in dry weight, nitrogen content, phosphorus content, and nitrogen: phosphorus ratio between chilled and fresh chick embryos and chilled and fresh human placenta. There was, however, a significant difference in the nitrogen content of the extracts prepared from fresh and from chilled tissues, It is suggested that chilling of tissues for 7 days at + 4 °C. prior to extraction may render the cells more easily destructible during extraction, and thus supply a better yield of nutritive substances.


mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Dario X. Ramirez-Villacis ◽  
Omri M. Finkel ◽  
Isai Salas-González ◽  
Connor R. Fitzpatrick ◽  
Jeffery L. Dangl ◽  
...  

ABSTRACT Glyphosate is a commonly used herbicide with a broad action spectrum. However, at sublethal doses, glyphosate can induce plant growth, a phenomenon known as hormesis. Most glyphosate hormesis studies have been performed under microbe-free or reduced-microbial-diversity conditions; only a few were performed in open systems or agricultural fields, which include a higher diversity of soil microorganisms. Here, we investigated how microbes affect the hormesis induced by low doses of glyphosate. To this end, we used Arabidopsis thaliana and a well-characterized synthetic bacterial community of 185 strains (SynCom) that mimics the root-associated microbiome of Arabidopsis. We found that a dose of 3.6 × 10−6 g acid equivalent/liter (low dose of glyphosate, or LDG) produced an ∼14% increase in the shoot dry weight (i.e., hormesis) of uninoculated plants. Unexpectedly, in plants inoculated with the SynCom, LDG reduced shoot dry weight by ∼17%. We found that LDG enriched two Firmicutes and two Burkholderia strains in the roots. These specific strains are known to act as root growth inhibitors (RGI) in monoassociation assays. We tested the link between RGI and shoot dry weight reduction in LDG by assembling a new synthetic community lacking RGI strains. Dropping RGI strains out of the community restored growth induction by LDG. Finally, we showed that individual RGI strains from a few specific phyla were sufficient to switch the response to LDG from growth promotion to growth inhibition. Our results indicate that glyphosate hormesis was completely dependent on the root microbiome composition, specifically on the presence of root growth inhibitor strains. IMPORTANCE Since the introduction of glyphosate-resistant crops, glyphosate has become the most common and widely used herbicide around the world. Due to its intensive use and ability to bind to soil particles, it can be found at low concentrations in the environment. The effect of these remnants of glyphosate in plants has not been broadly studied; however, glyphosate 1,000 to 100,000 times less concentrated than the recommended field dose promoted growth in several species in laboratory and greenhouse experiments. However, this effect is rarely observed in agricultural fields, where complex communities of microbes have a central role in the way plants respond to external cues. Our study reveals how root-associated bacteria modulate the responses of Arabidopsis to low doses of glyphosate, shifting between growth promotion and growth inhibition.


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