ABSTRACT
Aims: To characterize the growth, carbon assimilation and quality of Ipomoea aquatica as influenced by magnetic nanoparticles (MNP) application as well as to determine the best rates of iron oxide nanoparticles that give high growth, carbon assimilation and quality of Ipomoea aquatica. Study Design: Ipomoea aquatica plants were exposed to four different treatments of magnetic iron oxide nanoparticles (Fe3O4) (0, 50, 100 and 150 mg L-1). The experiment was conducted in a randomized complete block design (RCBD) with 3 replications. One unit of experiment consisted of 8 plants and there were 96 plants used in the experiment. Place and Duration of Study: Department of Biology, Faculty of Science, Universiti Putra Malaysia, between March 2018 and July 2018. Methodology: The growth parameters measured included: plant height, basal diameter, total leaf number, leaf temperature, total chlorophyll content and plant biomass. The carbon assimilation parameters were measured using IRGA (Infrared Gas Analyzer, LICOR 6400 XT Portable Photosynthesis System). i.e. transpiration rate (E), stomatal conductance and water use efficiency (WUE). The chlorophyll fluorescence were measured by using Pocket PEA that measured maximum efficiency of photosystem ii, (fv/fm), maximum quantum yield of phytochemical and non-photochemical process in photosystem II (fv/fo), minimal fluorescence (fo), performance index (PI) and Density of Reaction Centers Per PSII Antenna Chlorophyll (RC/ABS). Total phenolics and flavonoids contents in leaves were measured using Folin-Ciocalteu method. Results: It was observed that plant height, shoot length, plant temperature, total biomass, and total chlorophyll content were significantly influenced (p≤0.05) by the different concentrations of magnetic nanoparticles. The net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), maximum efficiency of photosystem II (Fv/fm), maximum quantum yield of phytochemical and non-photochemical process in photosystem II (Fv/fo), performance index and the density of reaction centers per PSII antenna chlorophyll of Ipomoea aquatica were significantly reduced at higher concentration of magnetic nanoparticles. However, water use efficiency and minimal fluorescence value (Fo) of Ipomoea aquatica increased with increase of MNP concentration. In addition, the application of magnetic nanoparticles significantly influenced (P≤0.05) the total flavonoids and total phenolics content in water spinach. Both of these parameters were increased when higher concentration of magnetic nanoparticles was applied to Ipomoea aquatica. This study showed that MNP affected the growth, carbon assimilation and secondary metabolites production of Ipomoea aquatica. Conclusion: In conclusion, the higher concentration of magnetic nanoparticles reduced the growth rate and carbon assimilation of water spinach and enhanced the production of secondary metabolites.
ABSTRACT
Aims: This study was conducted to investigate the effect of zinc oxide nanoparticles towards the Persicaria minor that can be used as a guidance for further toxicity investigation of ZnO-NPs. Study Design: A Completely Randomized Block Design (RCBD) was used with three replication. Each unit was consisted with eight plants and the total of 96 plants were used in this study. Place and Duration of Study: This study was conducted in plot 1, Vegetables Field plot for Teaching and Research, Taman Pertanian Universiti, Universiti Putra Malaysia (UPM) Selangor, Malaysia, from May 2018 until August 2018. Methodology: Persicaria minor were exposed to four different concentration of zinc oxide nanoparticles (ZnO-NPs) which were (50,100 and 150 mg/L) and 0 mg/L as a control. The ZnO-NPs was dissolved in distilled water before being applied to plants. 40 mL of ZnO-NPs solution was applied to each plant. The growth, carbon assimilation and also secondary metabolites were measured in this experiment. Results: The results showed that the treatment of zinc oxide nanoparticles enhanced growth of the Persicaria minor as the plant treated with zinc oxide nanoparticles had higher plant height and total biomass when compared to control treatment. However, the analysis revealed that the treatment of zinc oxide nanoparticles highly and significantly influenced the carbon assimilation and quality of this plant as the treated plants showed reduction in chlorophyll content, photosynthesis rate, stomatal conductance and transpiration rate but increased in production of secondary metabolites. The increased in production of plant secondary metabolites may be attributed by the plant protection mechanism due to metabolic stress caused by high concentration of zinc oxide nanoparticles. Conclusion: This research will progressively help in contributing some reliable and valid data on the effect of zinc oxide nanoparticles (ZnO-NPs), towards the Persicaria minor that can be used as guidance for further experimental investigation regarding this field.
ABSTRACT
Aims: Salinity is one of the major abiotic stress that negatively affects plant growth in germination and early seedling stages. Salinity has becoming a serious problem as most of the parts of worldwide lands were affected by high salt concentration. Therefore, the effects of salinity ranging from 0 mM, 25 mM, 50 mM and 75 mM Sodium chloride (NaCl) concentrations on germination and early seedling growth of water spinach and their salt tolerance mechanism. Study Design: Completely Randomized Design (CRD). Place and Duration of Study: This study was conducted at Tissue Culture Laboratory, Department of Biology, Faculty of Science in University Putra Malaysia (UPM) from June to August, 2018. Methodology: In order to study the effects of salinity on water spinach, several parameters have been taken into account for measurement which include water uptake percentage, germination percentage, germination index, mean germination time, relative injury rate, seed vigor, seedling height reduction, hypocotyl and radicle length, seedling biomass, salt tolerance, total phenolic content and total flavonoids contents. Results: The results obtained showed that salinity adversely reduced water uptake efficiency, seed vigor, hypocotyl and radicle length, total phenolic content and total flavonoids content of water spinach. The seedling height reduction of water spinach increased significantly in relative to increasing salinity. However, seeds treated in mild salt concentration at 25 mM of NaCl showed an increment of germination percentage and germination index. Conclusion: Salt tolerance of water spinach increased as the response towards increasing salinity.
ABSTRACT
Aims: To investigate the physiological, leaf gas exchange and quality of Centella asiatica (pegaga) under different nitrogen fertilization rates. Study Design: Centella asiatica were exposed to four different nitrogen fertilization rates (0, 50, 100, 150 kg/ha) using urea (46% N) as nitrogen sources. The experiment was conducted in a randomized complete block (RCBD) design with three replications. Each treatment consisted of eight plants making the total of plants used in this study is 96 plants. Place and Duration of Study: Department of Biology, Faculty of Science, Universiti Putra Malaysia From May 2016-June 2016. Methodology: The growth parameters measured include total leaves numbers, leaf area, total chlorophyll content and total plant biomass. The carbon assimilation parameters were measured using LICOR 6400 XT Portable Photosynthesis System i.e net photosynthesis (A), Transpiration rate (E) and water use efficiency (WUE). Total phenolic and flavonoids contents from the leaves extracts were measured using Folin-Ciocalteu reagents. Results: The growth parameters such as leaves number, chlorophyll content, leaf area and total biomass were significantly influenced by nitrogen fertilization (P≤ 0.05), However, there were no significant difference observed between 50, 100 and 150 kg N/ha suggesting that 50 kg N/ha was the efficient rates to apply to enhance the growth of this plant. Meanwhile, the net photosynthesis (A) and water use efficiency (WUE) were enhanced with the increasing rate of nitrogen from 0>150 kgN/ha. The production of total phenolics and flavonoids was found to be highest under 100 kg/ha. The harvest index of total phenolics also showed the applications of 100 kg/ha gave the highest harvest index compared to the other nitrogen treatments. Conclusion: This study indicated growth and carbon assimilation parameters were enhanced under higher nitrogen fertilization and production of secondary metabolites was decreased with high rates of nitrogen. The recommended nitrogen fertilization for C. asiatica was at 100 kg N /ha, where it obtained the highest harvest index.
ABSTRACT
Aims: To determine the impact of Pb on seed germination and early seedling development in A. auriculiformis species. Place and Duration of Study: The study was carried out in Department of Biology, University Putra Malaysia, between April 2016 and February 2017. Methodology: The concentrations of lead from 0 to 4 g/L (interval of 0.5 g/L) were used. Seeds were germinated in vitro condition. Different parameters were measured including germination percentage, seedling vigour index, tolerance index, germination index, mean germination time and relative injury rate. Results: The noticeable finding of this study reveals that A. auriculiformis seeds have the ability to germination and resist Pb toxicity up to 1.5 g/L. Increasing Pb concentration from 1.5 to 3.5 g/L decreased the germination percentage from 57% to 4% respectively. Conclusion: Acacia auriculiformis seeds germination in a high level of Pb (up to 1.5 g/L) indicated species resistance which probably can be used as Pb hyperaccumulator agent in areas or sites contaminated with this metal.
ABSTRACT
Aims: The aim of the experiment was to investigate the effect of thiourea on physiological characteristics of two rice (Oryza sativa L.) varieties under impact of salinity. Study Design: Experiment includes two rice varieties named as B-515 and KS-282, salinity level of 150 mM, thiourea of 0.25 mM alone and in combination were arranged in a completely randomized design (CRD). Place and Duration of Study: Old Botanical Garden, University of Agriculture Faisalabad, Pakistan, between 4th July and 21st August 2015. Methodology: Transplants of two rice varieties, Basmati-515 and KS-282 were exposed to salinity (150 mM) and thiourea (0.25 mM) after one month of transplanting in a Completely Randomized Design with three replications. Harvesting data was taken that include fresh and dry weights, leaf area, number of tillers, photosynthetic pigments, photosynthetic rate, transpiration rate, stomatal and substomatal conductance, water use efficiency and intrinsic CO2 concentration as well as chlorophyll contents in two rice varieties. Results: Thiourea treatment enhanced photosynthetic efficiency of Basmati-515 more than KS-282 by improving the chlorophyll and carotenoid contents and gas exchange attributes more than control. Conclusion: Salinity profoundly affect the physiological performance of two rice varieties especially that of KS-282, while 0.25 mM thiourea application unable to mitigate the effect of salinity but thiourea alone proved to be beneficial for both the rice varieties.
ABSTRACT
Aims: This study was conducted to characterize the growth patterns of tenera oil palm seedlings performance (Deli AVROS) under elevated CO2, that is expected to increase in the future due to climate change. Study Design: The palms were exposed to three carbon enrichment treatments: (1) ambient CO2 (400 ppm); (2) twice ambient CO2 (800 ppm), and (3) thrice ambient CO2 (1200 ppm). Randomized complete block design (RCBD) with three replications was used during the experiment using Deli AVROS seedlings. Place and Duration of Study: Department of Biology, Faculty of Science Universiti Putra Malaysia from March 2017 to December 2017. Methodology: Carbon dioxide enrichment treatments started when seedlings reached three months old by exposing them to three levels of CO2, i.e., ambient CO2 (400 ppm), twice ambient CO2 (800 ppm) and thrice ambient CO2 (1,200 ppm). Growth, carbohydrate and macronutrients properties were measured at the end of the treatment period of 3 months. Results: It was found that CO2 had the greatest influence on the growth over the three months’ period of experiment. As the level of CO2 increased, from 400>800>1200 ppm, the plant height, number of frond per plant, basal diameter, leaf area per seedling, root biomass, total dry matter, net assimilation rate (NAR) and relative growth rate (RGR) was significant increased between the CO2 levels. The enhanced plant growth under elevated CO2 might be contributed by increased in production of total non-structural carbohydrate (TNC) of the palm under elevated CO2. The increased in TNC exposed to elevated CO2 was supported by increase in sucrose and starch content under these conditions. More sucrose was available than starch indicate that no feedback inhibition was occurred and the palm have enough sink strength to cope with elevated CO2. The macronutrients contents (N, P, K, Ca, Mg) also was found to be reduced under elevated CO2 treatments, indicated that growth enhancement under elevated have dilute the nutrient content in the palms. Conclusion: In conclusion, the growth of oil palm seedlings was enhanced with elevated CO2 at double and triple concentration than the ambient. It was found that the increase might be due to increase in production of total non-structural carbohydrate. The enhanced growth also increased the macronutrient demands under the elevated levels of CO2. This show in future the palm needs more fertilizers with enhanced levels of elevated CO2.
ABSTRACT
Aims: An experiment was conducted to investigate the effect of a wide range of temperatures on the growth and physiology of Theobroma cacao, to study the differences between night and day temperatures and to determine the optimum temperature for the cocoa growth. Study Design: The experiment used five combinations of night and day temperatures (18°C and 30°C [18N30N], 18°C and 36°C; [18N 36D], 24°C and 24°C [24N24D], 24°C and 30°C [24N30D] and 24°C and 36°C [24N36D]) using complete randomized design (CRD). Place and Duration of Study: Crops and Environment Laboratory University of Reading and International Cocoa Quarantine Centre, between 23rd May 2016 and 25th July 2016. Methodology: The cocoa seedlings were put into five growth cabinets with five different night and day temperatures combinations (18°C and 30°C, 18°C and 36°C, 24°C and 24°C, 24°C and 30°C, 24°C and 36°C) for two months (63 days) under controlled environment condition where the relative humidity and vapor pressure deficit were controlled. Destructive harvest data was taken at end of the experiment which included fresh weight, dry weight, leaf area and root weight. Non-destructive measurements were height of the plant, photosynthetic rate, chlorophyll fluorescence and total chlorophyll content. Results: Treatment 24N30D have the best growth and treatment 24N36D had the lowest growth performances compared to other treatments. Conclusion: The growth was not only dependent on the day temperature, but also on the night temperature. A large gap between night and day temperatures (DIF) reduced the cocoa growth. The result also showed the optimum temperature amongst those studied for cocoa growth is the combination of 24°C night temperature and 30°C day temperature.
ABSTRACT
Aims: This study was conducted to investigate the effect of salinity by using a different concentration of sodium chloride (NaCl), on growth, chlorophyll fluorescence and secondary metabolites production of Centella asiatica. Study Design: Centella asiatica plants were exposed to four different concentration of sodium chloride (0, 50, 100 and 150 mM). This research was conducted using a randomized complete block design 4 x 3 with three replications for each treatment and each treatment consists of 12 plants regarding four times harvesting. Place and Duration of Study: Glasshouse of SLAM field, University Agriculture Park, Universiti Putra Malaysia from February to April 2015. Methodology: Salinity stress was induced by irrigating the plants using four salinity levels (0, 50, 100 and 150 mM) of salt concentrations for 12 weeks. The leaves number were counted manually and the total plant biomass was taken by calculating the dry weight of root, stem, and leaf per seedling. The total chlorophyll content in the leaves was measured using a SPAD chlorophyll meter. Chlorophyll fluorescence was measured using Hansatech Pocket PEA, The leaf gas exchange were determined using a LI-6400XT portable photosynthesis system. Total phenolics and flavonoid was determined using Folin-Ciocalteu reagent. Phytochemical screening was conducted to determine the presence of tannin, terpenoids, phenolics, flavonoids, saponin, and alkaloids of plant samples under salinity stress. Results: Increased in salinity levels from 0 > 150 mM, the number of leaves, total biomass and total chlorophyll content were gradually decreased. Centella asiatica exhibit a significant decrease in net photosynthesis (A), transpiration rate (E), maximum efficiency of photosystem II (fv/fm) and Performance index (PI) when the salinity level increased. However, it was noticed that salinity stress significantly enhanced the total phenolic and flavanoid content of C. asiatica. It was also observed, that under salinity there were more presence of phytochemicals (tannin, terpenoids, phenolics, flavonoids, saponin and alkaloids) compared to the control. Conclusion: This study revealed that the increase in salinity level have greatly reduced the growth of C. asiatica but high salinity level also can enhance the production of secondary metabolites (total phenolic and flavonoid content) in C. asiatica.
ABSTRACT
Aims: The study was conducted to investigate the impact of nitrogen fertilization on growth, leaf gas exchange and bio-metabolite accumulation in Ipomea aquatica. Treatment and Experimental Design: Ipomea aquatica plants were exposed to four different rates of nitrogen (0, 30, 60 and 90 N kg/ha) using Urea (46% N) as a nitrogen source. The experiment was laid out in Complete Randomize Design (CRD). Place and Duration of Study: Department of Biology, Faculty of Science, Universiti Putra Malaysia between September to November 2016. Methodology: Four nitrogen rates were applied (0, 30, 60 and 90 N Kg/ha) using Urea as a nitrogen source. The growth data collections were conducted once a week after the application of the treatments for the plant growth parameters. The total chlorophyll content in the leaves was measured using a Soil Plant Analytical Device (SPAD-502) chlorophyll meter. The leaf gas exchange was determined using a LI-6400XT portable photosynthesis system. Total phenolics and flavonoid were determined using Folin-Ciocalteu reagent. Results: It was found that the highest measurements of growth parameters namely plant height, leaf numbers, branches numbers, total biomass and chlorophyll content were observed at 90 kg N/ha and the lowest at 0 kg N/ha. As for the leaf gas exchange, the positive effect of nitrogen fertilization on kangkung was shown by the increased in photosynthesis rate (A) and stomatal conductance (gs) where the highest measurement recorded at 90 kg N/ha, and the lowest at 0 kg N/ha. However, the water use efficiency (WUE) decreased as the nitrogen rates increased. At lower rates of nitrogen fertilization (30 kg N/ha) produced the highest production of secondary metabolites, where the total phenolics and flavonoids production were enhanced compared to other nitrogen treatments. Conclusion: In conclusion, as the nitrogen rates increased, the growth and leaf gas exchange properties was enhanced however the production of secondary metabolites was decreased in I. aquatica.
ABSTRACT
Aims: To study the effect of different nitrogen fertilizer rates on growth, carbon assimilation and biochemical changes of Polygonum minus. Study Design: Polygonum minus were treated with different nitrogen fertilizer (0 kg N ha-1, 50 kg N ha-1, 100 kg N ha-1 and 150 kg N ha-1) using Urea (46%N) as a source of nitrogen. This experiment was arranged in Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: The experiment was conducted at Taman Pertanian Universiti (TPU), Universiti Putra Malaysia between April 2017 to July 2017. Methodology: The growth parameters measured includes the leaf number, plant height, diameter of the stem, and the leaf area. The carbon assimilation parameters were measured using LICOR 6400XT Portable Photosynthesis System. Total phenolic and flavonoids contents from the leaves extracts of Polygonum minus were measured using Folin-Ciocalteu reagents. Results: The best rates of nitrogen in enhancing the best growth and quality of Polygonum minus was observed at 150 kg N ha-1 in most parameters of growth and carbon assimilation. At the final harvest, the parameters such as number of leaves, plant height, stem diameters, total chlorophyll contents, leaves area, total dry weight, net assimilation rate (NAR), water use efficiency (WUE), net photosynthesis rate (A) stomatal conductance (gs), and maximal efficiency of photosystem II (fv/fm) were highest at 150 kg N ha-1treatments. In the terms of biochemical changes, the parameter such as total phenolics contents and total flavonoids gain the highest production of total phenolics and flavonoids at 50 kg N ha-1. Conclusion: This study indicated growth and carbon assimilation parameters were upregulated under higher nitrogen fertilization and production of secondary metabolites was decreased with high rates of nitrogen. The recommended nitrogen fertilization for P. minus was at 50 kg N Ha-1, where it obtained the highest harvest index.
ABSTRACT
Aims: This study was conducted to study the growth, leaf gas exchange and secondary metabolites of Orthosiphon stamineus as affected by Multiwalled carbon nanotubes application (MWCNT). Study Design: Orthosiphon stamineus were exposed to four different multi-walled carbon nanotubes (MWCNTs) concentration (0, 700, 1400 and 2100 mg L-1). The experiment was organized in a randomized complete block (RCBD) design with three replications. Each experimental unit consisted of twelve plants, and there were a total of 144 plants used in the experiment. Place and Duration of Study: Department of Biology, Faculty of Science Universiti Putra Malaysia between November 2016 to March 2017. Methodology: Each plant was watered with 50 mL of MWCNTs solution in week 2 and 9. The leaves number were counted manually and the total plant biomass was taken by calculating the dry weight of root, stem, and leaf per seedling The total chlorophyll content in the leaves was measured using a SPAD chlorophyll meter. The leaf gas exchange was determined using LI-6400XT portable photosynthesis system. Total phenolics and flavonoid were determined using Folin-Ciocalteu reagent. Results: It was found that application of MWCNTs would reduce the growth characteristics of this plant that was shown by decreased leaf numbers, total biomass and total chlorophyll content (TCC). As MWCNTs concentration increases from 0 > 2100 mg L-1, the leaf gas exchange parameter also shows reduced patterns. Generally, as the rate of MWCNTs increased from 700 > 2100 mg L-1 MWCNTs reduce the net photosynthesis (A), stomatal conductance (gs), transpiration rate (E) and increased the plant water use efficiency. The production of the secondary metabolites was directly dependable on MWCNTs concentration. As the rate was enhanced from 0 > 700 > 1400 > 2100 mg L-1 the production of total phenolics and flavonoids was enhanced. Conclusion: The current study revealed that the high application of MWCNTs concentration reduce the growth rate of O. stamineus, leaf gas exchange and simultaneously increase the production of secondary metabolites.