Intensive production of juvenile cuttings by mother microplant culture in Hydrangea macrophylla "Leuchtfeuer"

1996 ◽  
Vol 74 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Gilles Galopin ◽  
François Beaujard ◽  
Michel Gendraud
Keyword(s):  
Relative Humidity ◽  
Vegetative Propagation ◽  
Vegetative Growth ◽  
Woody Plants ◽  
High Relative Humidity ◽  
Hydrangea Macrophylla ◽  
Intensive Production

The vegetative propagation of hydrangea (Hydrangea macrophylla "Leuchtfeuer") should be explored through the architectural concepts of woody plants. The formation and continued culture of mother microplants in the greenhouse with high relative humidity and long days make up the new propagation method. Vegetative growth is characterized by the prolific production of homogenous cuttings as basal shoots in which the morphology of the axis is similar to that of plants produced by germination. There is considerable capacity for high levels of production, and it is a possible alternative to in vitro and traditional propagation. The morphogenetic basis of the functioning of these cultures is discussed in relation to juvenility and differentiation in woody plants. Keywords: morphogenesis, Hydrangea macrophylla, vegetative propagation, juvenility.

scholarly journals Shoot tip necrosis of in vitro plant cultures: a reappraisal of possible causes and solutions

Planta ◽  
2020 ◽  
Vol 252 (3) ◽  
Author(s):  
Jaime A. Teixeira da Silva ◽  
Esmaeil Nezami-Alanagh ◽  
María E. Barreal ◽  
Mafatlal M. Kher ◽  
Adhityo Wicaksono ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Ethylene Production ◽  
Physiological Condition ◽  
Shoot Tip ◽  
High Relative Humidity ◽  
Culture Vessel ◽  
In Vitro Shoots ◽  
In Vitro Plant ◽  
Shoot Tip Necrosis

Abstract Main conclusion Shoot tip necrosis is a physiological condition that negatively impacts the growth and development of in vitro plant shoot cultures across a wide range of species. Abstract Shoot tip necrosis is a physiological condition and disorder that can arise in plantlets or shoots in vitro that results in death of the shoot tip. This condition, which can spread basipetally and affect the emergence of axillary shoots from buds lower down the stem, is due to the cessation of apical dominance. STN can occur at both shoot multiplication and rooting stages. One of the most common factors that cause STN is nutrient deficiency or imbalance. Moreover, the presence or absence of plant growth regulators (auxins or cytokinins) at specific developmental stages may impact STN. The cytokinin to auxin ratio within an in vitro plant can be modified by varying the concentration of cytokinins used in the culture medium. The supply of nutrients to in vitro shoots or plantlets might also affect their hormonal balance, thus modifying the occurrence of STN. High relative humidity within culture vessels and hyperhydricity are associated with STN. An adequate supply of calcium as the divalent cation (Ca2+) can hinder STN by inhibiting the accumulation of phenolic compounds and thus programmed cell death. Moreover, the level of Ca2+ affects auxin transport and ethylene production, and higher ethylene production, which can occur as a result of high relative humidity in or poor ventilation of the in vitro culture vessel, induces STN. High relative humidity can decrease the mobility of Ca2+ within a plant, resulting in Ca2+ deficiency and STN. STN of in vitro shoots or plantlets can be halted or reversed by altering the basal medium, mainly the concentration of Ca2+, adjusting the levels of auxins or cytokinins, or modifying culture conditions. This review examines the literature related to STN, seeks to discover the associated factors and relations between them, proposes practical solutions, and attempts to better understand the mechanism(s) underlying this condition in vitro.

STUDIES ON RHIZOCTONIA SOLANI KÜHN: V. VIRULENCE IN STEAM STERILIZED AND NATURAL SOIL

1941 ◽  
Vol 19c (1) ◽  
pp. 1-8 ◽  
Author(s):  
G. B. Sanford
Keyword(s):  
Relative Humidity ◽  
Rhizoctonia Solani ◽  
Vegetative Growth ◽  
Hyphal Growth ◽  
High Relative Humidity ◽  
Natural Soil ◽  
Highly Pathogenic ◽  
Soil Mixture ◽  
Soil Inoculum

In general, the virulence of Rhizoctonia Solani Kühn, shown on potato stems, decreased as the proportion of inoculum, which was grown in steam sterilized soil, increased. Isolates highly pathogenic in a 1:15 soil inoculum—natural soil mixture were relatively weak in pure soil inoculum protected from outside contamination.Sclerotia developed and mycelia massed much more frequently and abundantly in the higher concentrations of soil inoculum than in the 1:15 soil-inoculum–natural-soil mixture. Thus, the evidence indicates that conditions favourable to marked vegetative growth of the pathogen tend to depress its virulence. The evidence available suggests that the new and vigorous hyphal growth necessary to sclerotia formation is initiated primarily by high relative humidity of the soil air.Further evidence was obtained that isolates of R. Solani pathogenic to potato may differ greatly in virulence and also in ability to form sclerotia, and also that the Corticium stage is an important source of pathogenic and sclerotia-bearing strains of this fungus. Finally, soil-grown inoculum 180 days old was as virulent as that freshly grown.

The Potential Migrated Mechanism of Water-Soluble Components in Pellets Prepared by Wet Extrusion/Spheronization: Effect of Drying Rate

2020 ◽  
Vol 17 ◽  
Author(s):  
Bingwei Wang ◽  
Jianping Liu ◽  
Zhenghua Li ◽  
Yulong Xia ◽  
Shuangshuang Zhang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Drying Rate ◽  
Scanning Calorimetry ◽  
Drying Temperature ◽  
Wet Extrusion ◽  
Extrusion Spheronization ◽  
Soluble Components

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.

Persistence of nosocomial bacteria on 2 biocidal fabrics based on silver under conditions of high relative humidity

2014 ◽  
Vol 42 (8) ◽  
pp. 879-884 ◽  
Author(s):  
Rosa López-Gigosos ◽  
Alberto Mariscal ◽  
Mario Gutierrez-Bedmar ◽  
Eloisa Mariscal-Lopez ◽  
Joaquín Fernández-Crehuet
Keyword(s):  
Relative Humidity ◽  
High Relative Humidity

The use ofin vitrogas production to evaluate rumen fermentation of leaves of 24 browse species indigenous to semi-arid areas of Zimbabwe

1998 ◽  
Vol 22 ◽  
pp. 238-240
Author(s):  
L. R. Ndlovu ◽  
L. Hove
Keyword(s):  
Woody Plants ◽  
Nutritive Value ◽  
Gas Production ◽  
Arid Areas ◽  
Chemical Methods ◽  
Tropical Regions ◽  
Biological Assays ◽  
Browse Species ◽  
Semi Arid

Browse species are important food resources in semi-arid areas, especially during the dry season when the nutritive value of grass is at its lowest. However, browse plants often contain secondary plant compounds which limit their nutritive value. Proanthocyanidins (PAs) (also called condensed tannins) and related flavonoids are a common constituent of woody plants in tropical regions (Mangan, 1988). PAs cause a bitter and astringent taste which lowers food palatability and they also lower the digestibility of proteins and carbohydrates (Jacksonet al., 1996). PAs also interfere with current chemical methods that are used for estimating nutritive value of foods (Reed, 1995). Biological assays, especially ,in vitrotechniques, have a potential to reflect better the nutritive value of foods that contain PAs. Thein vitrogas production technique has been found to reliably predict the nutritive value of temperate forages (Makkaret al., 1996). There has been limited research on its efficacy with tropical forages. The experiment reported here was conducted to test the hypothesis that gas production of tropical browse species reflects their content of fibre, protein and/or PAs.

scholarly journals Influence of Cytokinins in Combination with GA3on Shoot Multiplication and Elongation of Tea Clone Iran 100 (Camellia sinensis(L.) O. Kuntze)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Reza Azadi Gonbad ◽  
Uma Rani Sinniah ◽  
Maheran Abdul Aziz ◽  
Rosfarizan Mohamad
Keyword(s):  
Camellia Sinensis ◽  
Woody Plants ◽  
Clonal Propagation ◽  
Shoot Multiplication ◽  
Shoot Elongation ◽  
Nodal Segments ◽  
Nodal Segment ◽  
Liquid Form ◽  
Solid Media

The use ofin vitroculture has been accepted as an efficient technique for clonal propagation of many woody plants. In the present research, we report the results of a number of experiments aimed at optimizing micropropagation protocol for tea (Camellia sinensis(L.) O. Kuntze) (clone Iran 100) using nodal segments as the explant. The effect of different combinations and concentrations of plant growth regulators (PGR) (BAP, TDZ, GA3) on shoot multiplication and elongation was assessed. The influence of exposure to IBA in liquid form prior to transfer to solid media on rooting of tea microshoots was investigated. The results of this study showed that the best treatment for nodal segment multiplication in terms of the number of shoot per explant and shoot elongation was obtained using 3 mg/L BAP in combination with 0.5 mg/L GA3. TDZ was found to be inappropriate for multiplication of tea clone Iran 100 as it resulted in hyperhydricity especially at concentrations higher than 0.05 mg/L. Healthy shoots treated with 300 mg/L IBA for 30 min followed by transfer to 1/2 strength MS medium devoid of PGR resulted in 72.3% of shoots producing roots and upon transferring them to acclimatization chamber 65% survival was obtained prior to field transfer.

Organ culture with black cottonwood: morphogenetic response of female catkin primordia

1972 ◽  
Vol 50 (7) ◽  
pp. 1627-1631 ◽  
Author(s):  
K. S. Bawa ◽  
R. F. Stettler
Keyword(s):  
Organ Culture ◽  
Vegetative Growth ◽  
Callus Formation ◽  
Populus Trichocarpa ◽  
General Tendency ◽  
Black Cottonwood ◽  
Axillary Shoots ◽  
Female Sex ◽  
Female Catkin

Female catkin primordia of black cottonwood (Populus trichocarpa T. & G. ex Hook.) were cultured for 70 days on a modified Murashige and Skoog's (1962) medium in vitro. Explants 2–3 mm long, and with bud scales removed, gave the best results, many of them developing floral structures characteristic of the female sex. There was a general tendency to callus formation with increasing age of the culture, occasionally followed by a reversal to vegetative growth. Catkin primordia raised on Wolter's medium without auxin or kinetin, but with 6-benzylaminopurine, and at 250 ft-c for a 16-h photoperiod, proliferated axillary shoots in loco of pistils.

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