scholarly journals 207 Mycorrhizal Enhancement of the Physiology and Growth of Micropropagated Chile Ancho Pepper (Capsicum annuum L. cv. San Luis) Plantlets during Acclimatization and Post-acclimatization

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 426E-426
Author(s):  
Andres A. Estrada-Luna ◽  
Fred T. Davies ◽  
Jonathan N. Egilla
Keyword(s):  
Peak Stress ◽  
Dry Mass ◽  
Mycorrhizal Colonization ◽  
Ex Vitro ◽  
Poor Growth ◽  
San Luis ◽  
Leaf Chlorophyll ◽  
Leaf Dry Mass ◽  
Relative Water

The role of mycorrhiza fungi during acclimatization and post-acclimatization of micropropagated chile ancho plantlets was characterized through physiological and plantlet development changes. Regardless of mycorrhizal colonization, the pepper plantlets had initially low photosynthetic rates and poor growth following transplanting ex vitro. During the first days of acclimatization, water deficits occurred as evidenced by drastic reductions in relative water content. Consequently, transpiration rates and stomatal conductance (gs) declined, confirming that in vitro formed stomata were functional, thus avoiding excessive leaf dehydration and plant death. Mycorrhiza had a positive effect on gas exchange as early as day 7 and 8, as indicated by increasing photosynthesis (A) and gs. Mycorrhizal plantlets had reduced levels of abscisic acid (ABA) during peak stress (6 days after transplanting ex vitro), which corresponded with subsequent increases in gs and A. During acclimatization, A increased in both non-colonized and colonized plantlets, with greater rates observed in mycorrhizal plantlets. During post-acclimatization, mycorrhiza colonized 45% of the roots of pepper plantlets and enhanced plant growth by increasing leaf area, leaf dry mass, and fruit number. Mycorrhiza also enhanced total leaf chlorophyll content, A, and nutrient uptake of pepper plantlets, particularly N, P, and K. Early mycorrhizal colonization produced important benefits, which helped ex vitro transplanted plantlets recover during acclimatization and enhance physiological performance and growth during post-acclimatization.

scholarly journals 206 Growth, Gas Exchange, and Water Relations of Micropropagated Chile Ancho Pepper (Capsicum annuum L. cv. San Luis) Plantlets during Acclimatization and Post-acclimatization

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 426D-426 ◽  
Author(s):  
Andres A. Estrada-Luna ◽  
Fred T. Davies ◽  
Jonathan N. Egilla
Keyword(s):  
Gas Exchange ◽  
Capsicum Annuum ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Dry Mass ◽  
Ex Vitro ◽  
San Luis ◽  
Transplant Shock ◽  
Relative Water

Micropropagated chile ancho pepper (Capsicum annuum L. cv. San Luis) plants were transferred to ex vitro conditions to study plantlet performance and selected physiological changes that occur during acclimatization and post-acclimatization. The physiology of the plantlets was characterized by measuring leaf gas exchange and water status. Plant growth was determined by assessing plant height, leaf number, total leaf area, relative growth rate (RGR), and leaf, root, and stem dry mass. Measurements were taken at 0, 1, 2, 3, 6, 12, and 24 days after transplanting. After initial transplanting ex vitro to liner pots with soilless media, plantlet wilting was observed that correlated with reduced leaf relative water content (RWC). Water stress was partially alleviated by a reduction in stomatal conductance (gs), confirming that the in vitro formed stomata were functional and able to regulate transpiration (E) to minimize desiccation losses. Because of this stomatal control, plantlets had minimal transplant shock, recovered, and survived. Prior to transplanting, micropropagated plantlets showed heterotrophic/mixotrophic characteristics as indicated by low photosynthesis [(A) 4.74 μmol·m2·s-1]. During acclimatization, RWC, gs, E, and A were significantly lower 2 days after transplanting. However, within 6 days after transplanting, plantlets recovered and became autotrophic, attaining high A (16.3 μmol·m-2·s-1), gs, and E. The stabilization and improvement of plantlet water status and gas exchange during acclimatization and post-acclimatization closely correlated with dramatic increases in plantlet growth.

Variation of water relations parameters with extended rehydration time, leaf form, season, and proportion of leaf

1996 ◽  
Vol 26 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Donald B. Zobel
Keyword(s):  
Water Relations ◽  
Dry Mass ◽  
Current Data ◽  
Sampling Location ◽  
Tissue Elasticity ◽  
Leaf Form ◽  
Leaf Dry Mass ◽  
Location Patterns ◽  
Relative Water ◽  
Broadleaf Species

Pressure–volume curves were measured in October, February, and July for twigs of three deciduous, three evergreen broadleaf, four pine, and two other conifer species in the southern Appalachian Mountains, U.S.A. Data were analyzed to determine the influence on water relations parameters of rehydration time, sample leafiness, leaf form, season, and species within leaf form. Results of samples rehydrated overnight did not differ significantly from results of samples rehydrated overnight plus 24 h. Leafiness (leaf dry mass/sample dry mass) was occasionally related to water relations parameters. Water relations parameters usually varied with leaf form, and occasionally with sampling location. Patterns of variation among leaf forms differed for each combination of parameter and season: the strongest generality was that leafy deciduous twigs and pines had high tissue elasticity, whereas evergreen broadleaf species had low elasticity. Evergreen broadleaf species had a consistently high relative water content at zero turgor. Compared with literature values, these species had average to very high osmotic potentials. There was little consistency of water relations parameters among leaf forms and seasons in the overall (literature and current) data, although osmotic potential of all evergreen leaf forms rose from winter to summer.

scholarly journals Mycorrhizal Colonization Increases Herbicide Toxicity in Apple

1994 ◽  
Vol 119 (6) ◽  
pp. 1255-1260 ◽  
Author(s):  
C. Hamel ◽  
F. Morin ◽  
A. Fortin ◽  
R.L. Granger ◽  
D.L. Smith
Keyword(s):  
Relative Elongation ◽  
Dry Mass ◽  
Mycorrhizal Colonization ◽  
Mass Reduction ◽  
Apple Rootstocks ◽  
Apple Trees ◽  
Toxic Response ◽  
Herbicide Treatments ◽  
Mycorrhizal Plants

Herbicides are increasingly used in orchards. Since apple trees strongly depend on mycorrhizae, the effects of three commonly used herbicides on the host plant and endophyte were examined. Symbiosis between tissue-cultured P16 apple rootstocks and Glomus versiforme (Karsten) Berch was established under greenhouse conditions. Simazine (1, 2, 10, and 20 μg a.i./g), dichlobenil (1, 5, 10, and 25 μg a.i./g), paraquat (0.5, 1, 10, and 100 μg a.i./g), or water was applied to mycorrhizal and nonmycorrhizal plants as a soil drench. The response of mycorrhizal plants to herbicide was greater, and the relative elongation rate was more sharply reduced in mycorrhizal (76%) than in nonmycorrhizal plants (33%). Six weeks after herbicide application, dry mass reduction due to herbicides was similar (39% and 36%) for mycorrhizal and nonmycorrhizal plant shoots, respectively, while root dry mass reduction was larger for mycorrhizal (63%) than nonmycorrhizal plants (46%). None of the herbicide treatments affected root colonization. However, an in vitro hyphal elongation test with G. intraradices Schenck & Smith and herbicide-amended (0, 1, 10, 100, and 1000 μg a.i./g) gellan gum solidified water showed that either dichlobenil or paraquat, even at the lowest concentrations, could significantly reduce hyphal elongation. Simazine did not affect hyphal elongation in vitro, a result suggesting that improved absorption capacity of mycorrhizae explains, at least in part, the increased phytotoxicity of some herbicides. It was found that plant mortality was higher among mycorrhizal than nonmycorrhizal apple trees for all herbicide treatments. The increased CO2 assimilation rates of dichlobenil-treated mycorrhizal plants contrasted with the decreased rates of control plants measured 1 week after dichlobenil treatment. This indicates a physiological interaction between mycorrhizal colonization and dichlobenil in the toxic response of apple plants. Chemical names used: 2-chloro-4,6-bis-ethylamino-s-triazine (simazine), 2,6-dichlorobenzonitrile (dichlobenil), 1,1'-dimethyl-4,4'bipyridinium (paraquat).

scholarly journals Auxins Increase Post-transplant Growth of Vinca

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438A-438
Author(s):  
Marc van Iersel
Keyword(s):  
Indole Acetic Acid ◽  
Shoot Growth ◽  
Higher Plants ◽  
Dry Mass ◽  
Poor Growth ◽  
Post Transplant ◽  
Transplant Shock ◽  
Root And Shoot Growth ◽  
Small Roots

Auxins are commonly used to induce root formation during in-vitro culture of higher plants. Because transplanting is often accompanied by root damage and loss of small roots, auxins also could be beneficial in minimizing transplant shock. Vinca (Cataranthus rosea) seeds were germinated in a peat-lite growing mix and transplanted into pots (55 mL) filled with a diatomaceous earth (Isolite) 10 days after planting. Pots were then placed in a tray containing 62.5 mL of auxin solution per pot. Two different auxins [indole-acetic acid (IAA) and naphtylacetic acid (NAA)] were applied at rates ranging from 0.01 to 100 mg/L. Post-transplant growth was slow, possibly because of Fe+2-deficiencies. Both IAA (1–10 mg/L) and NAA (0.01–10 mg/L) significantly increased post-transplant root and shoot growth. As expected, NAA was effective at much lower concentrations than IAA. At 63 days after transplant, shoot dry mass of plants treated with 0.1 mg NAA/L was four times that of control plants, while 10 mg IAA/L increased shoot dry mass three-fold. High rates of both IAA (100 mg/L) and NAA (10–100 mg/L) were less effective. The highest NAA rate (100 mg/L) was phytotoxic, resulting in very poor growth and death of many plants. These results suggest that auxins may be a valuable tool in reducing transplant shock and improving plant establishment.

Influence of nitrogen fertilizers on yield and antifungal bioactivity of Tulbaghia violacea L.

2008 ◽  
Vol 27 (11) ◽  
pp. 851-857 ◽  
Author(s):  
E van den Heever ◽  
J Allemann ◽  
JC Pretorius
Keyword(s):  
Biological Activity ◽  
Antifungal Activity ◽  
Leaf Area ◽  
Large Scale ◽  
Plant Pathogens ◽  
Dry Mass ◽  
Application Rate ◽  
Nitrogen Fertilizers ◽  
Leaf Dry Mass

Tulbaghia is known to have antifungal properties that can be used in the treatment of both human and plant pathogens and is used in traditional medicine in South Africa. Increasing demands for plant material makes it necessary to cultivate this species on a large scale. Unfortunately, cultivation can lead to a reduction in the biological activity of plants making them unsuitable for use. In light of the lack of knowledge regarding the agronomic requirements of this plant, the aim of this study was to determine the effect of several rates and two forms of nitrogenous fertilizer on the yield and biological activity of Tulbaghia violacea. Plants were cultivated in sand while the basic fertilization used was the same as that of garlic (20 kg P ha−1, 75 kg K ha−1), a plant from the same family, containing similar active ingredients. Nitrogen was applied once at the beginning of the trial at rates of 30, 60, 120, and 180 kg ha−1 in the form of either nitrate or ammonium. Vegetative growth was quantified in terms of number of leaves and leaf area as well as root and leaf dry mass, while harvested material was tested for antifungal activity. The results indicated that compared with the untreated control, increasing N-rates in both the nitrate and ammonium forms increased leaf number and leaf area as well as both root and leaf dry mass. However, at a rate above 60 kg ha−1, and especially at 180 kg ha−1, the nitrate form stimulated growth more markedly than the ammonium form, whereas antifungal activity decreased sharply and almost linearly as the application rate was increased. Although growth was not stimulated to the same extent by the ammonium form, it increased the in-vitro antifungal activity at different levels during different times of the growing season. From an ornamental perspective, nitrate is the preferred nitrogenous form but, from a bioactivity perspective, ammonium is recommended.

scholarly journals Height and number of shoots on the survival and development of micropropagated bamboo plantlets during pre-acclimatization

2019 ◽  
Vol 49 ◽  
Author(s):  
Paulo Arthur Almeida do Vale ◽  
João Bosco de Oliveira Júnior ◽  
Frederico Henrique da Silva Costa ◽  
Jonny Everson Scherwinski-Pereira
Keyword(s):  
Survival Rates ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Ex Vitro ◽  
In Vitro Multiplication ◽  
Dry Biomass ◽  
Survival And Development ◽  
Ex Vitro Growth ◽  
The Relationship

ABSTRACT During the in vitro multiplication of bamboo plantlets, it is common the formation of shoots aggregates. Once individualized, these can yield a greater number of plantlets than if planted in clusters. This study aimed to evaluate the effect of the relationship between height and number of initial shoots in micropropagated bamboo plantlets on the survival and development of plants, during the pre-acclimatization stage. Guadua aff. chaparensis shoots, after successive subcultures of in vitro multiplication, were classified into three height classes (2.5-5.0 cm; 5.1-10.0 cm; 10.1-15.0 cm) and number of aggregate shoots (one shoot per plantlet/single-stem plantlet, two and three shoots per plantlet) and pre-acclimatized in a commercial substrate composition plus washed sand. The plantlets were evaluated for survival, height, number of new shoots and roots, shoot and root fresh and dry mass. In plantlets from micropropagation, the plant height does not influence the survival rates, being acclimatized preferably at heights between 5.0 cm and 15.0 cm, with survival rates of up to 97 %. Plantlets with height starting at 5.1 cm and composed of 2 or 3 initial shoots show a greater vigor and ex vitro growth, a fact evidenced by the higher values obtained in relation to height and emission of new shoots and roots, as well as a greater fresh and dry biomass accumulation.

scholarly journals Physiological and biochemical changes of micropropagated Dendrobium anosmum Lindl. in ex vitro acclimatization process

2019 ◽  
Vol 2 (3) ◽  
pp. 59-67
Author(s):  
Bang Phi Cao
Keyword(s):  
Water Content ◽  
Environmental Changes ◽  
Photochemical Efficiency ◽  
Biochemical Changes ◽  
Ex Vitro ◽  
In Vitro Plantlets ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Physiological And Biochemical

The ex vitro acclimatization process plays an important role in plant micropropagation. In vitro plantlets have to rapidly adapt to environmental changes. The current work aimed at assessing some physiological and biochemical changes of micropropagated Dendrobium anosmum Lindl. Plantlets during ex vitro acclimatization process, eg. contents of water (leaf relative water content), dry matter, proline and photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoid), chlorophyll fluorescence and antioxidant enzymes (peroxidase và catalase) activities. The analyzed results showed that water content decreased in acclimatized plantlets compared to in vitro ones. The chlorophylls and carotenoids contents of what were significantly higher in ex vitro plantlet leaves compared to the day 0 plantlets. The pigment contents were observed to increase during the ex vitro acclimatation process. When the plantlets were moved out of the in vitro medium, the maximum photochemical efficiency of photosystem II (Fv/Fm) significantly decreased at the early acclimatation points then restored at the end of acclimatation process. The content of proline and activities of antoxidant enzymes significantly increased with different periods of acclimatation process. The proline content and enzyme activities were recorded at the first ex vitro period when most water loss occurred in plantlets. These results suggest that Dendrobium anosmum Lindl in vitro plantlets have adapted to the transplantation by possesing some physiological responses of its photosynthetic system as well as its antioxidant machinery.

scholarly journals Low CO2 Levels Are Detrimental for In Vitro Plantlets through Disturbance of Photosynthetic Functionality and Accumulation of Reactive Oxygen Species

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 44
Author(s):  
Naser Askari ◽  
Sasan Aliniaeifard ◽  
Richard G. F. Visser
Keyword(s):  
Reactive Oxygen Species ◽  
Tissue Culture ◽  
Reactive Oxygen ◽  
Co2 Removal ◽  
Partial Recovery ◽  
Oxygen Species ◽  
Ex Vitro ◽  
Poor Growth ◽  
Co2 Levels

Photosynthesis of plantlets in tissue culture containers is not considered important, compared to photosynthesis of ex vitro plants, due to the exogenous source of carbohydrates present in tissue culture media. However, CO2 starvation can generate a burst of reactive oxygen species (ROS). We examined this phenomenon in tissue culture, since CO2 levels may become very low during the light period. The research was carried out with lily scales, regenerating adventitious bulblets, and with Arabidopsis seedlings. CO2 starvation was achieved by placing a small vial of concentrated KOH solution in the culture container. CO2 removal reduced the growth of regenerated lily bulblets by 33% or 23%, with or without sucrose in the medium, respectively. In Arabidopsis seedlings, CO2 removal decreased growth by 50% or 78% in the presence or absence of sucrose in the medium, respectively. Therefore, the addition of sucrose as a replacement for photosynthesis resulted in only partial recovery of growth. Staining with nitroblue tetrazolium (NBT) showed little to no ROS in ex vitro growing seedlings, while abundant ROS were detected in seedlings grown under in vitro CO2 starvation. Seedlings grown under normal tissue culture conditions (no CO2 withdrawal) showed low levels of ROS. In lily tissue culture, CO2 starvation decreased the maximum quantum efficiency of photosystem II (Fv/Fm) from 0.69 to 0.60, and in Arabidopsis from 0.76 to 0.62. Fv/Fm of ex vitro lily and Arabidopsis seedlings was 0.77 and 0.79, respectively. This is indicative of a disturbance in photosynthesis functionality and the occurrence of in vitro stress under reduced CO2 concentrations. We conclude that poor growth, in the absence of CO2, was partly due to strongly reduced photosynthesis, while the detrimental effects were most likely due to a burst of ROS.

Patrones de crecimiento de Cinchona officinalis in vitro y ex vitro; respuestas de plántulas micropropagadas y de semillas.

2017 ◽  
Vol 35 (1-2) ◽  
pp. 73-82
Author(s):  
Carlos Iván Espinosa ◽  
Gabriel Ríos
Keyword(s):  
Ex Vitro

El uso de herramientas biotecnológicas como la micropropagación se constituye en una alternativa de reproducción de especies amenazadas y con tamaños poblacionales reducidos. Sin embargo, uno de los problemas críticos en el uso de la micropropagación como herramienta de reproducción es la calidad de las plántulas resultantes en cuanto a su crecimiento y vigor. En el presente trabajo se evalua los efectos de la micropropagación sobre los patrones de crecimiento y sobrevivencia de plán­tulas in vitro de Cinchona officinalis L., una especie que ha sido fuertemente impactada por procesos de tala dentro de bosques naturales durante la época de la colonia. Se realizó un monitoreo de un total de 120 plántulas in vitro y 1988 plántulas ex vitro por 8 meses a partir del último repique. Adi­cionalmente, en cada plántula se contabilizó la cantidad de brotes axilares. Los resultados obtenidos mostraron un efecto remanente de los procesos de micropropagación, los cuales inicialmente inciden en la cantidad de brotes de las plántulas y en el crecimiento; sin embargo, este efecto no influye de forma negativa en la sobrevivencia de las plántulas durante la fase ex vitro

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