Les bruyères in vitro. VI. Croissance de Calluna vulgaris sur milieu strictement nitrique ou ammoniacal et cinétique du pH en fonction du développement des plantes

1986 ◽  
Vol 64 (5) ◽  
pp. 959-964 ◽  
Author(s):  
Benoit Congard ◽  
François Beaujard ◽  
Jean-Daniel Viemont

Calluna vulgaris L. Hull was cultured in vitro on a medium containing either nitrate or ammonium salts. Apical shoots, used as cuttings, regenerated twigs and roots after 15 to 25 days. The uptake of mineral nitrogen by roots had an influence on the pH of the medium. There was either an increase of pH when the N source was NO3 or a decrease in pH of the medium with ammonium. Acidification began with the formation of the first new roots; an increase in pH occurred later with the formation of second order roots. The results were difficult to express, owing to rooting heterogeneity. This problem was overcome by changing the origin of the abscissa, the new origin starting with the date of rooting. This procedure allowed the study of pH changes in relation to different stages of plant growth. With the aid of a standard curve, the study of the leakage of H+ and OH− showed great homogeneity in plant behaviour.

1994 ◽  
Vol 72 (10) ◽  
pp. 1503-1510 ◽  
Author(s):  
K. T. Bird ◽  
J. Jewett-Smith

An in vitro culture system was developed for axenic culture of the seagrass Halophila engelmannii Aschers. The culture system had a rhizome layer solidified with agar (0.8% w/v) and a liquid overlay layer. The rhizome layer contained artificial seawater (20%0, inorganic nutrients, plant growth regulators, sucrose (1% w/v), and activated charcoal (1% w/v). The overlay layer contained artificial seawater and inorganic nutrients. The medium f/4 provided the best source of inorganic nutrients of the five media compared. Axenic cultures of H. engelmannii died if NO3 was the only N source. They grew best when supplied with glutamic acid at a concentration of 3.4 mM as the N source. A combination of α-naphthaleneacetic acid at a concentration of 0.25 mg ∙ L−1 and 6-benzylaminopurine at a concentration of 10 mg ∙ L−1 provided the most rapid rates of propagation as measured by the numbers of pseudowhorls and branches produced. Key words: tissue culture, marine plants, media, plant growth regulators.


2011 ◽  
Vol 101 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Brantlee Spakes Richter ◽  
Kelly Ivors ◽  
Wei Shi ◽  
D. M. Benson

Wood-based mulches are used in avocado production and are being tested on Fraser fir for reduction of Phytophthora root rot, caused by Phytophthora cinnamomi. Research with avocado has suggested a role of microbial cellulase enzymes in pathogen suppression through effects on the cellulosic cell walls of Phytophthora. This work was conducted to determine whether cellulase activity could account for disease suppression in mulch systems. A standard curve was developed to correlate cellulase activity in mulches with concentrations of a cellulase product. Based on this curve, cellulase activity in mulch samples was equivalent to a cellulase enzyme concentration of 25 U ml–1 or greater of product. Sustained exposure of P. cinnamomi to cellulase at 10 to 50 U ml–1 significantly reduced sporangia production, but biomass was only reduced with concentrations over 100 U ml–1. In a lupine bioassay, cellulase was applied to infested soil at 100 or 1,000 U ml–1 with three timings. Cellulase activity diminished by 47% between 1 and 15 days after application. Cellulase applied at 100 U ml–1 2 weeks before planting yielded activity of 20.08 μmol glucose equivalents per gram of soil water (GE g–1 aq) at planting, a level equivalent to mulch samples. Cellulase activity at planting ranged from 3.35 to 48.67 μmol GE g–1 aq, but no treatment significantly affected disease progress. Based on in vitro assays, cellulase activity in mulch was sufficient to impair sporangia production of P. cinnamomi, but not always sufficient to impact vegetative biomass.


2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1,the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.


Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Rihab Djebaili ◽  
Marika Pellegrini ◽  
Massimiliano Rossi ◽  
Cinzia Forni ◽  
Maria Smati ◽  
...  

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 320
Author(s):  
Nisar Ahmad Zahid ◽  
Hawa Z.E. Jaafar ◽  
Mansor Hakiman

Ginger (Zingiber officinale Roscoe) var. Bentong is a monocotyledon plant that belongs to the Zingiberaceae family. Bentong ginger is the most popular cultivar of ginger in Malaysia, which is conventionally propagated by its rhizome. As its rhizomes are the economic part of the plant, the allocation of a large amount of rhizomes as planting materials increases agricultural input cost. Simultaneously, the rhizomes’ availability as planting materials is restricted due to the high demand for fresh rhizomes in the market. Moreover, ginger propagation using its rhizome is accompanied by several types of soil-borne diseases. Plant tissue culture techniques have been applied to produce disease-free planting materials of ginger to overcome these problems. Hence, the in vitro-induced microrhizomes are considered as alternative disease-free planting materials for ginger cultivation. On the other hand, Bentong ginger has not been studied for its microrhizome induction. Therefore, this study was conducted to optimize sucrose and plant growth regulators (PGRs) for its microrhizome induction. Microrhizomes were successfully induced in Murashige and Skoog (MS) medium supplemented with a high sucrose concentration (>45 g L−1). In addition, zeatin at 5–10 µM was found more effective for microrhizome induction than 6-benzylaminopurine (BAP) at a similar concentration. The addition of 7.5 µM 1-naphthaleneacetic acid (NAA) further enhanced microrhizome formation and reduced sucrose’s required dose that needs to be supplied for efficient microrhizome formation. MS medium supplemented with 60 g L−1 sucrose, 10 µM zeatin and 7.5 µM NAA was the optimum combination for the microrhizome induction of Bentong ginger. The in vitro-induced microrhizomes sprouted indoors in moist sand and all the sprouted microrhizomes were successfully established in field conditions. In conclusion, in vitro microrhizomes can be used as disease-free planting materials for the commercial cultivation of Bentong ginger.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 222
Author(s):  
Abdulaziz A. Al-Askar ◽  
WesamEldin I. A. Saber ◽  
Khalid M. Ghoneem ◽  
Elsayed E. Hafez ◽  
Amira A. Ibrahim

Presently, the bioprocessing of agricultural residues to various bioactive compounds is of great concern, with the potential to be used as plant growth promoters and as a reductive of various diseases. Lycopersiconesculentum, one of the most consumed crops in the human diet, is attacked by Fusarium wilt disease, so the main aim is to biocontrol the pathogen. Several fungal species were isolated from decayed maize stover (MS). Trichodermaasperellum was chosen based on its organic acid productivity and was molecularly identified (GenBank accession number is MW195019). Citric acid (CA) was the major detected organic acid by HPLC. In vitro, CA of T.asperellum at 75% completely repressed the growth of Fusariumoxysporum f. sp. lycopersici (FOL). In vivo, soaking tomato seeds in CA enhanced the seed germination and vigor index. T. asperellum and/or its CA suppressed the wilt disease caused by FOL compared to control. There was a proportional increment of plant growth and yield, as well as improvements in the biochemical parameters (chlorophyll pigments, total phenolic contents and peroxidase, and polyphenol oxidase activities), suggesting targeting both the bioconversion of MS into CA and biological control of FOL.


2021 ◽  
Vol 13 (14) ◽  
pp. 8030
Author(s):  
Shehzad Mehmood ◽  
Amir Abdullah Khan ◽  
Fuchen Shi ◽  
Muhammad Tahir ◽  
Tariq Sultan ◽  
...  

Plant growth-promoting rhizobacteria play a substantial role in plant growth and development under biotic and abiotic stress conditions. However, understanding about the functional role of rhizobacterial strains for wheat growth under salt stress remains largely unknown. Here we investigated the antagonistic bacterial strain Bacillus aryabhattai PM34 inhabiting ACC deaminase and exopolysaccharide producing ability to ameliorate salinity stress in wheat seedlings under in vitro conditions. The strain PM34 was isolated from the potato rhizosphere and screened for different PGP traits comprising nitrogen fixation, potassium, zinc solubilization, indole acetic acid, siderophore, and ammonia production, along with various extracellular enzyme activities. The strain PM34 showed significant tolerance towards both abiotic stresses including salt stress (NaCl 2 M), heavy metal (nickel, 100 ppm, and cadmium, 300 ppm), heat stress (60 °C), and biotic stress through mycelial inhibition of Rhizoctonia solani (43%) and Fusarium solani (41%). The PCR detection of ituC, nifH, and acds genes coding for iturin, nitrogenase, and ACC deaminase enzyme indicated the potential of strain PM34 for plant growth promotion and stress tolerance. In the in vitro experiment, NaCl (2 M) decreased the wheat growth while the inoculation of strain PM34 enhanced the germination% (48%), root length (76%), shoot length (75%), fresh biomass (79%), and dry biomass (87%) over to un-inoculated control under 2M NaCl level. The results of experiments depicted the ability of antagonistic bacterial strain Bacillus aryabhattai PM34 to augment salt stress tolerance when inoculated to wheat plants under saline environment.


1974 ◽  
Vol 29 (1-2) ◽  
pp. 39-41 ◽  
Author(s):  
H. Veen

Abstract Studies in vitro on the binding of phospholipids with IAA, α-NAA and some of their biologically inactive analogues demonstrate that the observed interaction between IA A and lecithin is not related to the primary action of the hormone in plant growth.


Sign in / Sign up

Export Citation Format

Share Document