Effect of heavy metal stress on emerging plants community constructions in wetland

2010 ◽  
Vol 62 (10) ◽  
pp. 2459-2466 ◽  
Author(s):  
Han Peng ◽  
Wu Geng ◽  
Wu Yong-quan ◽  
Li Mao-teng ◽  
Xiang Jun ◽  
...  

In this paper, we report the effects of heavy metals (HMs) (cadmium and mercury) on seed germination and seedling growth of Phragmites australis and Triarrhena sacchariflora, which are the two main typical emerging plants in Hongze Lake wetland. The results showed that there was a reduction in germination percentage, germination index and seedling length as HM concentration in the growing media increased for both treatments. The effect of HMs toxicity on seed germination and seedling growth of T. sacchariflora was more obvious than of P. australis. At the stage of seed germination, P. australis and T. sacchariflora were sensitive to Hg2 +  and Cd2 + , respectively, and Hg2 +  was more toxic than Cd2 +  at the stage of seedling growth. The effect of HMs toxicity is not invariable during plant growth. Compared to the stage of seedling growth, P. australis and T. sacchariflora are more susceptible to HMs at the stage of seed germination. In addition, we calculated the ecological thresholds of P. australis to Cd and Hg are 19.32 and 1.08 mg kg−1, and that of T. sacchariflora to Cd is 4.62 mg kg−1 based on the lab simulation. The results also indicated that the species of P. australis is more tolerant than T. sacchariflora to the HMs and is a better candidate for restoration in Hongze Lake wetland ecosystem.

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 757-761 ◽  
Author(s):  
Nagi Reddy Achhireddy ◽  
Megh Singh

Allelopathic effects of lantana (Lantana camaraL. ♯3LANCA) residues (root, shoot), foliar leachates, and the soil (where lantana was grown) on milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed germination and growth over a 30-day period were examined. Foliar leachates or the soil collected from the field where lantana had been growing had no effect on the final germination percentage or the seedling growth of milkweedvine. Incorporation of dried lantana shoot or root material into soil had no effect on the final percentage germination but caused significant reductions in milkweedvine growth over a 30-day test period. Roots were more inhibitory than shoots. Fifty percent of milkweedvine seedlings died within 15 days after germination at 1% (w/w) dried lantana root incorporation into the soil, and higher concentrations increased seedling death. Lantana roots incorporated into the soil produced foliar symptoms such as wilting and desiccation, whereas lantana shoots incorporated into the soil produced yellowing of the foliage of milkweedvine. Allelopathic activity of lantana residues was still strong even after decomposition of lantana residues for 4 weeks prior to the planting of milkweedvine seeds.


2012 ◽  
Vol 76 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Maryam Haghighi ◽  
Zahra Afifipour ◽  
Maryam Mozafarian

The Alleviation Effect of Silicon on Seed Germination and Seedling Growth of Tomato Under Salinity StressThis study was conducted to evaluate the effectiveness of silicon (Si) application under salinity levels on seed germination and growth characteristics of tomato seeds. A laboratory experiment was performed on completely randomized design with two levels of salinity (25 and 50 mM NaCl) and 2 concentration of Si (1 and 2 mM) with 4 replications. Germination percentage, germination rate, seedling shoot and root length, fresh and dry weight of seedling and mean germination time was measured. Seed germination ofLycopersicon esculentumL. was significantly affected by salinity levels, Si and their interaction. Germination characteristics of tomato seeds decreased drastically by increasing NaCl concentrations. However, 1 mM Si had positive effects on seed germination characteristics and improved germination percentage, germination rate and mean germination time. Si alleviated the harmful effect of salinity stress on tomato seed germination at almost all germination characteristics.


2021 ◽  
Vol 27 (2) ◽  
pp. 139-152
Author(s):  
Muhammad Sikander Hayyat ◽  
Muhammad Ehsan Safdar ◽  
Muhammad Mansoor Javaid

Red sprangletop (Leptochloa chinensis L.) is a problematic weed of aerobic rice (Oryza sativa L.) that greatly reduces in yield. The laboratory studies were undertaken to confirm allelopathicity of its plant leachates and soil-decomposition plant residues towards emergence and seedling growth of rice. In first experiment, aqueous extracts from various plant parts of red sprangletop (stem, root, leaves, flower and entire plant) at their 5% (w/v) concentration were applied to germinating rice seeds. In second experiment, soil-decomposed red sprangletop plant residues of variable concentrations (2, 4 and 6% w/w) were used as germination media for rice. Among plant parts, red sprangletop leaves showed maximum allelopathic effect by fully inhibiting the germination of rice while its stem could be positioned at second situation as it caused 60, 73, 84.13 and 86 % reductions in germination percentage, germination index, seedling length and seedling dry biomass of rice as compared with control, respectively. This treatment also resulted in maximum delays in mean germination time (up to 4.80 days) and days taken to 50% germination (up to 4.40 days) of rice. The highest concentrated (6%) soil-decomposed plant residue of red sprangletop significantly diminished the germination percentage, germination index, seedling length and seedling vigor index that were 35.13, 23.26 and 41.61% lower than control. It very well may be presumed that liquid concentrates of leave and stem soil-decomposed plant residues of 6% concentration had different kind of allelochemicals that inhibited the germination, seedling growth and development of rice.


2021 ◽  
Vol 9 ◽  
Author(s):  
Meng-Yao Ma ◽  
Hong-Yuan Ma ◽  
Lei Wang ◽  
Wen-Wen Qi ◽  
Shao-Yang Li ◽  
...  

Soil salinity is important abiotic stress affecting various ecosystems worldwide such as grassland. Distinct ecotypes often evolve within species by natural selection to facilitate adaptation to different types of environmental stress. Leymus chinensis is a perennial rhizomatous grass that is widely distributed in the eastern Eurasian steppe; it has two main ecotypes, namely, yellow-green (YG) and gray-green (GG), which differ in their strategy for coping with salinity stress. Few studies have examined the seed germination of the two ecotypes under salinity stress. In this study, the seed germination and seedling growth of two ecotypes of L. chinensis in response to different levels of salinity (NaCl) stress [0 (control), 20, 50, 100, and 200 mM] were examined. Then, ungerminated seeds were placed under normal conditions to evaluate seedling growth following exposure to salt stress (i.e., regermination). The germination percentage was significantly higher, and the mean germination time was significantly shorter in the GG ecotype than in the YG ecotype at all NaCl concentrations. As the salinity level increased, the radicle length of the two ecotypes decreased; however, GG had longer radicles and a higher number of radicles, even at 200 mM NaCl when no radicle protruding from the seed coat was detected in YG. The shoot length of GG was significantly longer than that of YG at all NaCl levels. After salinity stress was removed, the seed germination percentage increased as the original concentration of NaCl applied increased, but the total germination percentage did not significantly differ among NaCl concentrations. The total seed germination percentage of GG was approximately 80%, whereas that of the YG was approximately 20%. The seedling length of regerminated seeds for both GG and YG was similar. The thousand-grain weight of GG was significantly higher than that of YG. GG was more salt-tolerant than YG and might be better capable of surviving in harsher environments, suggesting that GG might be particularly useful for saline grassland restoration.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tatsiana A. Ratnikova ◽  
Ramakrishna Podila ◽  
Apparao M. Rao ◽  
Alan G. Taylor

Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20(fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1154 ◽  
Author(s):  
Jinxia He ◽  
Ruixin Li ◽  
Xue Sun ◽  
Wenxia Wang ◽  
Jianen Hu ◽  
...  

Calcium alginate (CaAlg) submicroparticles have a potential application in agricultural delivery systems. This study investigated the effects of CaAlg submicroparticles on seed germination and seedling growth of wheat. CaAlg submicroparticles with a Z-average diameter of around 250.4 nm and a measured zeta potential value of about −25.4 mV were prepared and characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS). After this, the effects of the concentration of CaAlg submicroparticles (10–500 μg/mL) on germination percentage, seedling length, the number of adventitious roots, chlorophyll content and soluble protein content were evaluated. The results demonstrated a significant increase in the level of germination percentage (9.0%), seedling index (50.3%), adventitious roots (27.5%), seedling length (17.0%), chlorophyll (8.7%) and soluble protein contents (4.5%) at a concentration of 100 μg/mL. However, an inhibitory effect was observed at a concentration of 500 μg/mL. The SEM examination showed that CaAlg submicroparticles could be successfully adsorbed onto the surface of the wheat seed. Further studies proved that CaAlg submicroparticles at a concentration of 100 μg/mL promoted the expression of indole-3-acetic acid (IAA)-related genes (YUCCA9, AUX1, ARF and UGT) in wheat, which resulted in an increase of 69% and 21% in IAA concentration in wheat roots and shoots, respectively.


2014 ◽  
pp. 145-157
Author(s):  
Sladjana Samuilov ◽  
Danijela Djunisijevic-Bojovic ◽  
Matilda Djukic ◽  
Jelena Rakovic

Some heavy metals such as Zn are essential micronutrients for plants. However, in a high concentration in soils they could cause repression of growth with toxicity symptoms. It is therefore very important to investigate the species that are tolerant to high concentration of zinc which have the ability to survive on soils contaminated with heavy metals. This paper presents an investigation of the effect of elevated Zn concentrations on the germination and seedling growth of the invasive tree species Ailanthus altissima (Swingle) Mill., aimed at a better understanding of its adaptation ability to heavy metal stress and potential use in phytoremediation. Seeds of Ailanthus altissima were treated with Zn concentrations of 25, 100 and 250 ?M in form of zinc sulfate. After germination, the seedlings at the stage of first leaf development were transferred into a growing chamber in the hydroponic system where zinc sulfate was added in the concentrations of 100, 250 and 500 ?M. The results showed that Zn treatments, including the highest concentration, have caused a reduction in seed germination parameters. Considering the hypocotyl and radicle length, there was no significant statistical difference among the treatments, but further growth of young seedlings in hydroponics under high concentrations of Zn, cause an inhibition of the root system growth and repress development of assimilating organs. Seeds and seedlings of A. altissima are tolerant to elevated Zn concentrations at early stages of development. However, later on with leaves development, the inhibitory effect of the strongest concentrations is expressed.


Author(s):  
Namrah Zafar ◽  
Muhammad Zafar Iqbal ◽  
Muhammad Shafiq ◽  
Muhammad Kabir ◽  
Zia-ur-Rehman Farooqi

Aim: This study was conducted to examine the effects of exhaust pollutants and garden soil extract on seed germination and seedling growth of some economically important crops, maize and sunflower. Study Design: The in-vitro experimental design was completely randomized. Place and Duration of Study: The experimental site was Department of Botany, University of Karachi, Pakistan and the experiment was lasted for 10 days in Ecology laboratory. Methodology: The seeds of maize and sunflower were placed in front of the generator to exposed exhaust pollutants daily, 10 minutes, for 10 days. After the exposure of exhaust gas seeds were shifted into Petri dishes. The garden soil was obtained from mini garden of the Department of Botany, University of Karachi. The different concentrations of garden soil with distilled water were made and filtered. This filtered solution was assumed as the standard solution, which was 100%. From this standard solution, further dilution of 25%, 50% and 75% were made. Distilled water was used as a control for the experiment. Three best seedlings were selected from each Petri dish for the determination of mean values of seed germination (percentage), root, shoot and seedling length and seedling dry weight.   Results: This publication will help to understand the importance of exhaust pollutant impact and soil on crop growth and productivity. The soil quality influences plant growth and identifies the impact of exhaust emission on plant growth. The effects of exhaust pollutants of the generator and different concentration of garden soil on seed germination and seedling growth of two important crops Zea mays (L.) maize and sunflower Helianthus annuus (L.) were recorded. The treatment of different concentration of garden soil extract (0, 25, 50, 75, and 100%) affected seed germination percentage, root, shoot, and seedling length and seedling dry weight of both crop species. The soil extract at 25% significantly (p<0.05) affected the seed germination percentage of H. annuus as compared to control. The treatment of soil extract also decreased seedling growth performance of Z. mays and H. annuus as compared to control. A significant (p<0.05) decrease in seedling length of Z. mays becomes evident that exhaust treatment affected the seedling dry weight performance of maize as compared to control. Similarly, exposure of exhaust pollutant affected the seedling dry weight of Z. mays and H. annuus as compared to control treatment.  The effects of garden soil extract on seed germination and seedling growth of Z. mays was found higher as compared H. annuus. Conclusion: It was concluded that the treatment of exhaust emissions from a portable power generator fueled negatively affected the seed germination and seedling growth performance of maize and sunflower as compared to control treatment. A comparison between the seed germination percentage, seedling growth and biomass production performance of maize was found highly affected as compared to sunflower.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
SUPRIYA DIXIT ◽  
R. K. GUPTA

Currently, a real challenge for the workers in the agricultural research field is to stop or reduce the use of expensive agrochemicals/ chemical fertilizers which are hazardous to the environment as well as human health. Present study was aimed to improve the growth and obtain optimum yield of Vigna crop with eco-friendly, non-toxic way and to reduce the use of agrochemical/chemical fertilizer application in agricultural activities. A pot experiment was conducted to study the effect of chemical fertilizer (DAP) and biofertilizer ( Rhizobium strain) separately and in combination on seed germination and seedling growth (at 30 days) based on morphological parameters such as seedling length (cm), fresh weight (g), dry weight (g) and leaf area (cm)2 of Vigna radiata (L.) Wilczek. After one month (30 Days) observations, it was found that seedling length, fresh and dry weights and leaf area were maximum in T4 and minimum in T15, T7 and T8 favored improved seedling length and leaf area whereas T7, T8, and T9 favored improved fresh and dry weights as compared to control.


Author(s):  
Gamze Kaya

The study aimed to evaluate the use of germination indices as a screening tool for salinity tolerance during germination and early seedling growth of pepper cultivars, and to distinguish the potential for genetic responses to salt tolerance. In the study, the seeds of seven pepper cultivars were germinated at increasing NaCl levels of 5, 10, 15 and 20 dS/m and distilled water as the control treatment for 14 days. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), seedling length (SL), seedling fresh weight (SFW) and vigor index (VI) were investigated. Results showed that germination percentage decreased with increasing NaCl levels while the highest germination percentage at 20 dS/m was 92% in BT Burdem with no significant reduction. Seedling growth of pepper cultivars was severely inhibited by increasing salinity stress. SFW was depressed depending on reduction in SL due to increasing NaCl. BT-Burli and BT İnce Sivri were the most tolerant cultivars to NaCl and they were used for genetic resources towards salinity. Seedling growth was much more sensitive to salinity than germination because of the highest percent reduction in seedling growth parameters. Among the parameters, GSTI gave the highest significant correlation coefficient with SL and SFW; indicating that it would be useful for estimating seedling growth. It was concluded that genotypic variation was observed among pepper cultivars for salinity tolerance and GSTI could be used for a predictor for salinity tolerance.


Sign in / Sign up

Export Citation Format

Share Document