Azizollah Khandan Mirkohi; Seyyedeh Razieh Waeez Mousavi; Ahmad Khalighi; Rouhangiz Naderi
Abstract
Introduction: Cultivation of ornamental plants in terrariums is common, but the use of flowering plants in such environment is difficult and rarely seen. Common geranium (Pelargonium hortorum L.H.) is the most well-known potted and garden plant in the top of 25 popular world's market rankings. Today, ...
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Introduction: Cultivation of ornamental plants in terrariums is common, but the use of flowering plants in such environment is difficult and rarely seen. Common geranium (Pelargonium hortorum L.H.) is the most well-known potted and garden plant in the top of 25 popular world's market rankings. Today, one of the main goals of commercial producers is the production of the uniform plants in terms of morphological traits such as uniformity in the height that needs some management. To achieve this objective plant genetic potential, managing the growth and environmental factors, restrictions on root environment, water and nutrition to a level that does not affect the quality as well as application of chemical plant growth retardants (PGRs) could be considered. Paclobutrazol (PBZ) commercially known as Bonzi and chlromequat chloride (CCC) known as cycocel are commonly used to control the height of some pot plants. Additionally, Benzyladenine (BA) as a synthetic cytokinin can influence the growth characters of plants. This experiment conducted to evaluate the effect of paclobutrazol, cycocel and benzyladenine on the growth and flowering of geranium as a flowering terrarium plant.
Materials and Methods: The effect of PBZ, CCC and BA evaluated as a factorial experiment based on CRD on the growth and flowering of geranium (Pelargonium hortorum L.H. Bailey ‘Horizon’) as terrarium plant. At first, geranium seeds planted in tray cells as plugs filled by sieved black peat to below 2 mm in early autumn, Oct. 2015. Seedlings were grown in a greenhouse conditions with an average day/night temperatures of 25/20 ± 2 °C, nourished with 1:2 ratio diluted Hoagland nutrient solution as irrigation demand, until 2-4 leaves stage then transferred into terrarium containers (with 20 cm of middle diameter and 15 cm of height). Inside container relative air humidity was about 75±5% and growing environment light intensity (PPF) was about 500 µmole m-2S-1. Irrigation and nutrition also applied at seedling stage in terrarium. Terrarium glass container totally filled to a quarter of volume considering a drainage layer of gravel, activated charcoal, a layer of substrate barrier (plastic net), potting soil containing of 20 vol.% sieved field loam soil, 10 vol.% of fine perlite and 70 vol.% of sieved black peat. PBZ at the levels of 0, 25 and 50 ppm and CCC at the levels of 0, 1000 and 2000 ppm applied one month after transplanting (Feb. 2015) and BA treatment for flowering management applied at the levels of 0, 50 and 100 ppm four months after transplanting (May 2016). Growth and flowering characters evaluated thoroughly while root and shoot fresh and dry weight, photosynthetic pigments of chlorophyll, carotenoids, and anthocyanin index assessed at the end of the experiment.
Results and Discussion: Both growth retardants PBZ and CCC led to a significant reduction in plant height in high concentrations. Thus, the effect of PGRs on plant height was significant, while the effect of BA and its interactions by PGRs on this trait was not considerable. Effective treatments on this trait were PBZ in concentration of 50 ppm and then CCC in 2000 ppm. In particular, the use of these concentrations without BA treatment led to the shortest plants. Comparison of plants cultivated in the pot and terrarium conditions showed that the growth conditions had a considerable and significant impact on plant height and growth. Stem diameter, number of leaves and leaf area significantly reduced by PBZ compared to the control, but CCC did not show a significant effect on these traits. Smaller stem diameter occurred through 25 ppm of PBZ together with 50 ppm of BA. Application of PBZ especially at 25 ppm resulted in a significantly reduced number of plant leaves and leaf area compared to the control and application of CCC. Application of CCC at the level of 2000 ppm combined with BA of 50 ppm caused to a significant increase of leaf area compared to the control. Results on the number of lateral branches showed that application of PGRs had no effect on this character, while restriction of growth in terrarium conditions led to decrease in the number of lateral branches. Number of lateral branches raised by application of BA and CCC, while less number of branches observed with PBZ treatments especially at the level of 25 ppm. Chlorophyll and anthocyanin content of leaves decreased by both retardants. Days to flowering shortened by PBZ treatment of 50 ppm and slightly by CCC treatment of 1000 ppm in terrarium conditions. In general, flowering process accelerated via these treatments, while PBZ of 25 ppm and CCC of 2000 ppm delayed the flowering of plants compared to the control. The acceleration effect of 50 ppm PBZ was superior to the effect of 1000 ppm of CCC. The effect of BA on flowering time was insignificant despite of initial prospect. Finally, the photosynthetic pigments, leaf area and stem diameter increased because of BA, while flowering characters not influenced by means of BA. In general, 50 ppm of PBZ and without BA treatment was able to improve production characters of geranium plants in terrarium conditions.
Conclusions: The goal of this research was managing the growth and flowering of geranium in the restricted terrarium conditions by PGRs. It was found that treatment of plants by 50 ppm of PBZ could properly control the plant height and whereas positively accelerated flowering without and negative side effects on the plant performance. It seems that a good hormonal balance performed by this concentration of PBZ compared to CCC and BA. Early flowering is a positive quality trait for the most flowering ornamental plants. However, BA application itself and in interaction with CCC could enhance the photosynthetic pigment contents and thus improved the growth characters but it could not influence flowering traits even though delayed the flowering, significantly. Restriction of the root area via planting in terrarium could considerably limit the vegetative growth characters and delayed the flowering compared to the potted plants.
Mehdi Mohebodini; Zahra Azimzadeh; Esmaeil Chamani; Malihe Erfani
Abstract
Introduction: Lily (L. ledebourii) is the rarestspeciesof thegenusLilium, and grows in Caucasus region. Iranis one of the important distribution areas of this endangered species. It is important as an ornamental plant due to its large and attractive white flowers that are equal to those of commercial ...
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Introduction: Lily (L. ledebourii) is the rarestspeciesof thegenusLilium, and grows in Caucasus region. Iranis one of the important distribution areas of this endangered species. It is important as an ornamental plant due to its large and attractive white flowers that are equal to those of commercial lilies in terms of beauty.The two main constraints on growing this plant are a low multiplication rate and the high cost of bulb production. Five to ten flowers commonly appear on each plant, even specimens with up to 15 flowers have been observed. Plant tissue culture techniques are widely used in plant propagation and using these methods can effectively provide micro-propagation of this plant in large scale. High percentage ofregeneration is necessary for plant protection, using in the breeding programs and gene transfer to this plant. Therefore, the effect of plant growth regulators and abiotic stress (ultrasound) werestudied on the bulblet production and root induction of Lilium ledebourii.
Materials and Methods: The experiment was factorial based on completely randomized design with four replicattions and was carried out in tissue culture lab of University of MohagheghArdabili in 2015. For this purpose, segmentsof scale explant was treated with ultrasound and cultured on MS medium supplemented with different concentrations of NAA and BA alone and/or in combination with each other. In this experiment, different concentrations of NAA (0, 0.01, 0.1 and 1 mgl-1) and BA (0, 0.01, 0.1 and 1 mgl-1) and different Ultrasound exposure duration (0, 5, 10, 20 and 30 second) were studied. In order to remove possible contamination from the media, all media were autoclaved for 20 minutes at 121 °C. At the end of the experiment, the number of bulblet, root length, fresh weight of bulblet were recorded. The cultures were kept at 25±2°C under illumination with daylight fluorescent lamps (30 mol m-2s-1) at 16 h photoperiod. Data was subjected for analysis of variance and compare means using SPSS 16.
Results and Discussion: The results showed that ultrasound had negative effect onroot length, so that the highest root length was observed in explants without ultrasound treatment. Result also indicated that ultrasound had positive effect on bulblet production and root induction. A different effect of growth regulators was observed in similar media on the bulblet formation percentage. The 0.1 NAA concentration had a higher efficiency while increasing NAA insignificantly decreased bulblet induction. The highest total weight and number of bulblets obtained by 0.1 mgl-1 NAA. Concentrations of NAA increased rooting percentage. Different concentrations of NAA had also significant effects on some traits. So that, the highest weight of bulblets obtained by 0.01 and 0.1 mgl-1 BA and the highest number of roots obtained in control. Bulblet maximum mean weightwas in30 seconds ofultrasoundtreatment, which hada significantdifference with the control treatment (without ultrasoundtreatment). In the other hand, ultrasound increased the number and weight of bulblets.Mechanical stress and microstreaming by acoustic cavitation might be considered as the most possible cause of the various physiological effects of ultrasound on cells. The enhancement of V-ATPase transport and ATP hydrolysis activities seem to be an ultrasound-induced metabolic response of cells. High-intensity ultrasound is well known to be destructive to biological materials, disrupting the cell membranes and deactivating biological molecules such as enzymes and DNA. Low-intensity ultrasound, on the other hand, has shown a range of sub lethal biological effects that are of potential significance in biotechnology. There are several processes that take place in the presence of cells or enzymes activated by ultrasonic waves. High-energy ultrasonic waves break the cells and denature the enzymes. Low-energy ultrasound can modify cellular metabolisms or facilitate the uptake of nutrient, and make them easily through the cellular walls and membranes. In the case of enzymes, the increase in the mass transfer rate of the reagents to the active site seems to be a most important factor.
Conclusions: The results showedthatthebulblet production at first stages and a little root formation in tissue culture is useful for fast bulblet inductionandthenrooting. Finally, it seems that ultrasound in combination with plant growth regulators have the potential to produce the highest average number of bulblets in the scale explant.
Vahid Rouhi; Behrooz Shiran; Abdolrahman Mohamadkhani
Abstract
The Zinnia (Zinnia elegans J.) flower has many applications in landscape design, whereas lack of adequate conditions and nutritions in some cases can reduce the quality and number of flowers. Therefore, control of growth conditions is very important related to nutrition and application of growth regulators ...
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The Zinnia (Zinnia elegans J.) flower has many applications in landscape design, whereas lack of adequate conditions and nutritions in some cases can reduce the quality and number of flowers. Therefore, control of growth conditions is very important related to nutrition and application of growth regulators to improve the quality and quantity of flowers. Flower's morphology and longevity are two main factors that are used to evaluate the quality of flowers. Application methods that could increase the vase life, is important. A research conducted to investigate the effects of calcium chloride, gibberellin and Benzyladenin on zinnia quantitative and qualitative characteristics in 2010. Experiment carried out in a factorial in randomized complete block design with four replications at the Sharekord University's research farm. Treatments consisted calcium chloride (0, 0.5 and 1 gram per liter), Gibberellin (0, 75 and 150 mg per liter) and benzyladenine (0, 75 and 150 mg per liter) to be sprayed on plant two times in 10 days interval. The result showed that calcium chloride increased stem diameter, number of lateral shoots and flowers and storage vase life. Gibberellin reduced flower and stem diameter, number of axillary shoots and flower. Gibberellins also reduced the beginning of flowering time from transplanting and increased the vase life of the flower on plant and storage. Furthermore, benzyladenine significantly increased the quality and quantity of plant except the flowering period.
