scholarly journals Effects of UV-C radiation on common dandelion and purple coneflower: First results

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Donato Castronuovo ◽  
Adriano Sofo ◽  
Stella Lovelli ◽  
Vincenzo Candido ◽  
Antonio Scopa

Ultraviolet-C (UV-C) light (100 ≤ λ ≤ 280 nm) is a ionizing radiation that can damage living organisms. An experiment was conducted on plants of common dandelion (Taraxacum officinale Weber, T. Densleonis Desf.) and purple coneflower [Echinacea purpurea, (L.) Moench] irradiated with UV-C at different exposition times, under controlled conditions and grown in self-produced characterized compost, to assess the effect of different doses UV-C radiation on some physiological parameters. Trials have been carried out using a black chamber equipped with an UV-C lamp in which plants were divided in four groups on the basis of UV-C irradiation period (10, 30, 60, and 120 min). Non-irradiated plants were kept as controls. Plant photosynthetic performance, chlorophyll content (SPAD) and some morphologic traits were recorded before, immediately after irradiations and 20 days weeks later. The effects on photosynthetic performances and chlorophyll contents (SPAD) were evaluated and compared with data obtained in similar experiments where tomato plants were irradiated at different times with UVC light. In both species, SPAD values decreased as the irradiation period became longer. The two species showed different gas exchange dynamics, depending on the UV-C exposure time. Two months after the UV-C irradiation, plant dry weight measured at 120-min UV-C exposure was significantly lower than the control.

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 186c-186
Author(s):  
Janine O. Haynes ◽  
Wallace G. Pill

Purple coneflower seeds following priming (-0.04 MPa, 10 days, 15C, darkness) osmotically in polyethylene glycol 8000 (PEG) or matrically in expanded no. 5 vermiculite had greater germination rate and synchrony at continuous 20C or 30C than untreated seeds, but germination percentage was unaffected. Inclusion of 5.5 × 10-2 M gibberellic acid (GA3 as ProGibb Plus 2X, Abbott Laboratories, N. Chicago, Ill.) further improved germination rate and synchrony at 20C, but not at 30C. In a greenhouse study (30C day/27C night, July-August natural light), seeds primed in PEG or vermiculite containing G A3 compared to untreated seeds had 6 percentage points higher maximum emergence (ME), 3.3 fewer days to 50% ME, 1.9 fewer days between 10% and 90% ME, 116% greater shoot dry weight, and 125% longer leaves at 16 days after planting in peat-lite. Inclusion of ethephon (0.01 m, as Florel) either alone or with GA3 during priming provided no benefit to seed germination or seedling emergence. Moistened vermiculite substituted for PEG solution as a priming medium for purple coneflower seeds, the priming benefit on seedling emergence and growth being enhanced by 5.5 × 10-2m G A3 inclusion in the priming media.


2001 ◽  
Vol 11 (2) ◽  
pp. 194-199
Author(s):  
Bruce R. Roberts ◽  
Henry F. Decker ◽  
Kenneth J. Bagstad ◽  
Kathleen A. Peterson

Two biosolid-containing waste media [sewage sludge compost and incinerated biosolids (flume sand)] were tested individually, together, and in combination with a commercial growing medium for growing wildflower sod in greenhouse trials over a 3-year period. A medium composed of flume sand and Metromix (7:3 weight/weight) in 7.5 {XtimesX} 10.5 {XtimesX} 2-inch deep (19 {XtimesX} 27 {XtimesX} 5-cm) plastic trays seeded at 20 oz/1000ft2 (6.1 g·m-2) with cosmos (Cosmos bipinnatus), cornflower (Centaurea cyannis), plains coreopsis (Coreopsis tinctoria), white yarrow (Achillea millefolium) and purple coneflower (Echinacea purpurea) produced a suitable wildflower sod in 10 to 12 weeks. A single application of slow release fertilizer (Osmocote 14-14-14, 14N-4.2P-11.6K) applied as a top dressing had no significant effect on sod development; however, a 4-mil [0.004-inch (0.10-mm)] polyethylene barrier placed in the base of each container resulted in increased dry weight accumulation and a higher root to shoot ratio relative to sod grown without plastic.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 551A-551
Author(s):  
Jenny Heringer Vires ◽  
Robert Anderson ◽  
Robert Geneve

Purple Coneflower [Echinacea sp. (Asteracea)] is of great value to the horticultural, pharmaceutical, and herbal industry. More research is needed to determine cultural practices that will produce a plant high in biomass and phenolic content, the chemical used for testing the quality of the harvested plant on a percent basis of roots, flowers and vegetative parts. The objective of this experiment is to determine if biomass and phenolic content of Echinacea purpurea and E. purpurea `Magnus' is influenced by fertilization after flower bud removal and vegetative pruning. The second objective of this study is to form an evaluation of the differences in biomass and phenolic content of five cultivars of E. purpurea and five species of Echinacea. Biomass and phenolic content will be evaluated to determine if exposing these plants to various treatments increases the quality of the plant over 1 and 2 years of growth. Differences in dry weights of Echinacea species and cultivars harvested after the first year of growth was determined. There was a significant difference in total dry weight between E. purpurea cultivars. Echinacea purpurea `Bright Star' and `Clio' significantly produced the most total dry weight compared to all other cultivars. There was no significant difference in root or flower biomass between cultivars. Biomass of Echinacea species was significantly different in root, vegetaive and flower parts. The total biomass of E. purpurea and E. tennesseensis was significantly higher compared to other species. Echinacea pallida and E. paradoxa were not significantly different from E. purpurea in root biomass, even though both species were small in above ground growth. Echinacea tennesseensis significantly produced 45% to 105% more flowers compared to other species. Differences in phenolic content between species and cultivars will also be presented.


HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1443-1444 ◽  
Author(s):  
N. Wartidiningsih ◽  
R.L. Geneve

Six seed lots of purple coneflower were purchased from four commercial seed sources and evaluated for germination in either light or darkness in combination with two temperature regimes (constant 27C vs. alternating 30C for 8 hours and 20C for 16 hours). Seed lot differences accounted for the majority of variation, with two seed lots exhibiting high (81% to 91%) germination and the remaining seed lots having 39% to 66% germination. There was no effect of light on germination, regardless of the seed lot. However, alternating temperatures improved germination in one of the low-germination seed lots. Seed size and inflorescence position did not affect seed germination. Seed harvested at physiological maturity (maximum seed dry weight), but before drying had occurred, had a higher germination percentage than seeds harvested after desiccation, and they maintained a higher germination percentage even after 1 year in storage.


2017 ◽  
Vol 9 (3) ◽  
pp. 160
Author(s):  
Reza Isazadeh Hajagha ◽  
Saliha Kirici ◽  
Leila Tabrizi ◽  
Ahmad Asgharzadeh ◽  
Aydin Hamidi

In order to study the effects of biological and chemical fertilizers on quantitative and qualitative yields of purple coneflower, an experiment was carried out during 2010-2012. The morphological traits such as plant height, number of lateral shoots, shoot fresh and dry weight, root fresh and dry weight, number of inflorescences per plant, number of flower buds per plant, and essential oil content and yield were measured. The results showed significant effects of the treatments on the growth parameters. In the second year, the mixture of the three bacteria plus mycorrhizal inoculum improved important parameters such as shoot dry weight (40.42%), root dry weight (60.02%), and number of inflorescences per plant (65.68%). Interestingly, these values were not significantly different from obtained results by the chemical fertilizers. Additionally, the essential oil content in plants treated with the mixture of the three bacteria were 152.14% and 25.11% higher than the control plants in the first and the second year, respectively. The essential oil yield in plants treated with the mixture of the three bacteria was higher than those treated with the chemical fertilizers in two years. The results indicate that using biological fertilizers is a good choice to reduce the use of chemical fertilizers as an important tool to contribute to a sustainable agriculture.


2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Donato Castronuovo ◽  
Adriano Sofo ◽  
Stella Lovelli ◽  
Vincenzo Candido ◽  
Antonio Scopa

Artificial light, supplied by fluorescent lamps, has been effectively utilized in controlled- environment chambers for horticulture and floriculture nursery. This experiment aimed at investigating whether light-emitting diodes (LEDs) have the same effectiveness on plant morphology, photosynthetic and physiological responses as FLUORA lamps. Seedlings of common dandelion (<em>Taraxacum</em> <em>officinale</em>) and purple coneflower (<em>Echinacea</em> <em>purpurea</em>), species of high interest for their nutraceutical properties, were grown in controlled-environment chambers for 50 days under LED and FLUORA light sources as sole-source lighting systems, and the effects of artificial light supplies on plant photosynthetic performance and chlorophyll content (SPAD) were evaluated. The results were compared to plants grown under natural sunlight. In both species, total chlorophyll content (SPAD) values decreased for plants under sunlight, and for those grown under FLUORA lighting throughout the experimental period, while the values measured for plants grown under LEDs maintained a relatively constant value. At the end of the experiment, plant dry matter in both species was significantly lower under LEDs and FLUORA lighting, than the plants exposed to solar light. The two species showed different gas exchange dynamics under LEDs and FLUORA lighting, and photosynthetic performance decreasing after 10 days of light treatment compared to plants under sunlight. The results demonstrated that for common dandelion and purple coneflower photosynthetic processes are often modified when the species are cultivated under these artificial lighting and in controlled- environment chambers, because lamps do not able to generate the same spectrum and energy of sunlight.


Planta Medica ◽  
2013 ◽  
Vol 79 (05) ◽  
Author(s):  
MT Khosravi ◽  
A Mehrafarin ◽  
H Naghdibadi ◽  
E Khosravi

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 332
Author(s):  
Min Li ◽  
Haoyun Wang ◽  
Xizhou Zhao ◽  
Zhongke Lu ◽  
Xueguang Sun ◽  
...  

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yankun Sun ◽  
Jiaqi Xu ◽  
Xiangyang Miao ◽  
Xuesong Lin ◽  
Wanzhen Liu ◽  
...  

AbstractAs the global population continues to increase, global food production needs to double by 2050 to meet the demand. Given the current status of the not expansion of cultivated land area, agronomic seedlings are complete, well-formed and strong, which is the basis of high crop yields. The aim of this experiment was to study the effects of seed germination and seedling growth in response to silicon (from water-soluble Si fertilizer). The effects of Si on the maize germination, seedling growth, chlorophyll contents, osmoprotectant contents, antioxidant enzyme activities, non-enzymatic antioxidant contents and stomatal characteristics were studied by soaking Xianyu 335 in solutions of different concentrations of Si (0, 5, 10, 15, 20, and 25 g·L−1). In this study, Si treatments significantly increased the seed germination and per-plant dry weight of seedlings (P < 0.05), and the optimal concentration was 15 g·L−1. As a result of the Si treatment of the seeds, the chlorophyll content, osmotic material accumulation and antioxidant defence system activity increased, reducing membrane system damage, reactive oxygen species contents, and stomatal aperture. The results suggested that 15 g·L−1 Si significantly stimulated seed germination and promoted the growth of maize seedlings, laying a solid foundation for subsequent maize growth.


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