scholarly journals Effects of Salt Stress on the Leaf Shape and Scaling of Pyrus betulifolia Bunge

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 991 ◽  
Author(s):  
Yu ◽  
Shi ◽  
Hui ◽  
Miao ◽  
Liu ◽  
...  

Leaf shape can reflect the survival and development of plants in different environments. In particular, leaf area, showing a scaling relationship with other leaf-shape indices, has been used to evaluate the extent of salt stress on plants. Based on the scaling relationships between leaf area and other leaf-shape indices in experiments at different levels of salt stress, we could examine which leaf-shape indices are also related to salt stress. In the present study, we explored the effects of different salt concentration treatments on leaf dry mass per unit area (LMA), the quotient of leaf perimeter and leaf area (QPA), the quotient of leaf width and length (QWL), the areal quotient (AQ) of left and right sides of a leaf and the standardized index (SI) for bilateral symmetry. We treated Pyrus betulifolia Bunge under NaCl salt solution of 2‰, 4‰ and 6‰, respectively, with fresh water with no salt as the control. The reduced major axis (RMA) was used to fit a linear relationship of the log-transformed data between any leaf trait measures and leaf area. We found that leaf fresh weight and dry weight decrease with salt concentration increasing, whereas the exponents of leaf dry weight versus leaf area exhibit an increasing trend, which implies that the leaves expanding in higher salt environments are prone to have a higher cost of dry mass investment to increase per unit leaf area than those in lower salt environments. Salt concentration has a significant influence on leaf shape especially QWL, and QWL under 6‰ concentration treatment is significantly greater than the other treatments. However, there is no a single increasing or decreasing trend for the extent of leaf bilateral symmetry with salt concentration increasing. In addition, we found that the scaling exponents of QPA versus leaf area for four treatments have no significant difference. It indicates that the scaling relationship of leaf perimeter versus leaf area did not change with salt concentration increasing. The present study suggests that salt stress can change leaf functional traits especially the scaling relationship of leaf dry weight versus leaf area and QWL, however, it does not significantly affect the scaling relationships between leaf morphological measures (including QPA and the extent of leaf bilateral symmetry) and leaf area.

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
R. Desingh ◽  
G. Kanagaraj

Present research was carried out with the aim of identifying effect of salt stress (NaCl 0(Control), 40, 80, and 120 mM) on growth and physiochemical parameters of sesame (Sesamum indicum L.) variety CO-1 and KRR-2. Various parameters such as height of the plant, leaf area, fresh weight of the whole plant and dry weight of whole plant and decreased the content of physiochemical parameters were analyzed. All the parameters were recorded at 30th Days after Treatment (DAT). Analysis revealed a significant reduction in all parameters with increased salt concentration. This experiment carried out fully pot culture methods. Severity of salinity stressed condition were also observed with increased salinity concentration level at the same time decrease in all growth parameter were non-significant in stressed plant as compared two sesame varieties CO-1 and KRR-2. CO-1 in the sesame varieties at 120mM high salt concentration increased with lower decreased was observed in height of the plant, Leaf area, fresh weight of the whole plant and dry weight of whole plant and decreased the content of physiochemical parameters compared to other sesame varieties KRR-2 under salt stress condition. The results indicated that plants of sesame variety CO-1 exhibited higher adaptive potential under salinity stress as judged by higher growth and higher content of physiochemical parameters when compared to variety KRR-2.


Trees ◽  
2020 ◽  
Author(s):  
Pei-Jian Shi ◽  
Yi-Rong Li ◽  
Ülo Niinemets ◽  
Edward Olson ◽  
Julian Schrader

Abstract Key message Using more than 10,000 bamboo leaves, we found that the scaling between leaf surface area and length follows a uniform power law relationship mainly relying on the degree of variation in leaf shape (reflected by the ratio of leaf width to length). Abstract A recent study based on leaf data of different plant taxa showed that the scaling of leaf surface area (A) with linear leaf dimensions was best described by the Montgomery equation (ME) that describes A as the product of leaf length (L) and width (W). Following from ME, a proportional relationship between A and the square of L has been proposed, but the validity of this simplified equation strongly depends on leaf shape (W/L ratio). Here, we show that the simplified equation can be applied to a group of closely related plants sharing a similar W/L ratio with low degree of uncertainty. We measured A, L and W of more than 10,000 leaves from 101 graminoid taxa (subfamily Bambusoideae) having similar elongated leaf shapes. We found that ME applies to the leaves of all bamboo taxa investigated. The power law equation that was used to describe a scaling relationship of A vs. L also predicted leaf area with high accuracy, but the variability measured as the root-mean-square error (RMSE) was greater than that using ME, indicating that leaf width also plays an important role in predicting leaf area. However, the dependence of the prediction accuracy of A on W is intimately associated with the extent of the variation in W/L ratio. There was a strong positive correlation (r = 0.95 for the 101 bamboo taxa) between RMSE and the coefficient of variation in W/L ratio. Thereby, our results show that leaf area of bamboo plants can be calculated by the product of L and W with a proportionality coefficient ranging from 0.625 to 0.762, i.e., the leaf area of bamboo leaves approximately equals 70% of a rectangular area formed by L and W. The pooled data of ln(A) vs. ln(WL) of 101 bamboo taxa were located on or very close to the regression line without being affected by interspecific differences. However, interspecific differences in W/L ratio largely affected the scaling relationship of A vs. L, which led to large deviations of the data of ln(A) vs. ln(L) from the regression line. This implies that the square relationship between A and L does not apply to all species even if those are very closely related taxa.


2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.


Author(s):  
Hongwen Xu, Yan Lu ◽  
Shuyuan Tong

The impact of arbuscular mycorrhizal fungi (AMF) Glomus. tortuosum on morphology, photosynthetic pigments, chlorophyll (Chl) fluorescence, photosynthetic capacity and rubisco activity of maize under saline stress were detected under potted culture experiments. The experimental result indicated the saline stress notably reduced both dry mass and leaf area in contrast with the control treatment. Nevertheless, AMF remarkably ameliorated dry mass and leaf area under saline stress environment. Besides, maize plants appeared to have high dependency on AMF which improved physiological mechanisms by raising chlorophyll content, efficiency of light energy utilization, gas exchange and rubisco activity under salinity stress. In conclusion, AM could mitigate the growth limitations caused by salinity stress, and hence play a very important role in promoting photosynthetic capacity under salt stress in maize.


2011 ◽  
Vol 39 (2) ◽  
pp. 219 ◽  
Author(s):  
Asghar RAHIMI ◽  
Ali BIGLARIFARD

A hydroponic culture was carried out with strawberry cv. Camarosa to investigate the effects of four salinity levels and four different substrates on plant growth, mineral nutrient assimilation and fruit yield of strawberry. Total dry weight accumulation of plants was not inhibited at low salinities, but it was significantly inhibited at 60 mM NaCl. Dry mass (DM) partitioning in NaCl-stressed plants was in favor of crown and petioles and at the expense of root, stem and leaf, whereas leaf, stem and root DM progressively declined with an increase in salinity. Specific leaf area (SLA) and leaf area ratio (LAR) significantly decreased in cv. Camarosa at 60 and 90 mM. Results also showed that the presence of NaCl in the root medium induced an increase in total Na+ content of the plants in the shoot and root. Despite Na+ and K+, the increase in total inorganic ions resulted from increasing salinity, with Ca2+ and Mg2+ concentrations decreasing in shoot and increasing in roots with an increase in salinity. For all micro- and macroelements however, significant concentration changes related to different substrates were not detected in the present experiments. Results also showed a significant decline of Fe content of 40% and 49% in shoot and root, respectively.


2012 ◽  
pp. 61-72 ◽  
Author(s):  
Matilda Djukic ◽  
Danijela Djunisijevic-Bojovic ◽  
Mihailo Grbic ◽  
Dragana Skocajic ◽  
Dragica Obratov-Petkovic ◽  
...  

Relative amounts of nutrients, especially nitrogen, the most abundant macro-element, and also the distribution of ammonium ions in relation to nitrate ions, in the soils of different ecosystems, are determined by many factors. The most important are: temperature, pH of substrate, accumulation of organic matter, presence of allelopathic compounds, degree of oxygenation, etc. The ability of plants to adapt to these variations influences their production of bio-mass, the rate of expansion in different habitats, and the impact on ecosystem and biodiversity. This paper analyzes the impact of different forms of nitrogen (NO3 - and NH4 +) on the growth of seedlings of invasive species Acer negundo L. and Ailanthus altissima (Mill.) Swingle. The results show that nitrogen nutrition only in the form of NH4 + ions significantly affects the reduction in shoot dry weight. Compared to the nutrition with both forms of nitrogen together, aerial parts of Ailanthus altissima were reduced by 62.5%, and leaf area by 66.7%, while Acer negundo seedlings had reduction in dry mass of aboveground part by 89.5%, root by 81.2% and leaf area by 85.8%. Nutrition with nitrate form of nitrogen led to a proportionally small, but statistically significant decrease in dry mass of aboveground parts and roots as well as leaf area of Acer negundo, while in Ailanthus altissima seedlings, it was only the mass reduction of aboveground parts that was significantly influenced, so it can be assumed that this species is more resistant to the lack of both forms of nitrogen. The fact that both species produced significantly more biomass when nitrogen was present in both forms may be important in controlling the spread of alien species, or in their potential use in phytoremediation.


2018 ◽  
Vol 1 ◽  
pp. 19-25 ◽  
Author(s):  
Ja'afar Umar ◽  
Adamu Aliyu ◽  
Kasimu Shehu ◽  
Lawal Abubakar

Many plants accumulate high levels of free proline content (pro) and glycine betaine (GB) in response to abiotic stress, Pro and GB act as an osmoprotectant. Generally, these levels are high than those required to be used in protein synthesis. Salinity inhibition of plant growth is the result of osmotic and ionic effect and different plant species have developed different mechanisms to cope with those effects. In this study, accumulation of osmolytes of twenty tomato genotypes was evaluated in response to salinity stress. The seedlings of each genotype were divided into three groups, Sodium chloride (NaCl) dissolved in irrigation water to make variant concentration of 30 and 60 mg/L of salt concentration using electrical conductivity meter which were used to water the plants. Level of free proline and glycine betaine were measured. Data obtained were subjected to one way analysis of variance using SPSS (20) Statistical Software. Dry mass accumulation decreased with increased salt concentration in all the genotypes. However, the result differ significantly (P< 0.05). The highest dry mass accumulations at control were recorded on Tropimech and Giofranco F. with 6.00 and 5.97. The lowest dry mass accumulations were recorded on plant treated with 60mg/L of salt. Dangainakawa recorded the least accumulation of dry mass on plants treated with 60mg/l of salt with 0.90g followed by Dan Gombe with 1.47g respectively. The highest free proline content of 1.46 µmolg-1was recorded on Dan gainakawa at plant treated with 60 mg/L of NaCl. The lowest proline content was recorded at control on Giofranco F. with 0.17 µmolg-1The highest GB content in all the plants were recorded at plants treated with 60 mg/L. However, the highest GB content (1.67) among the 20 (P<0.05) were recorded at 60 mg/L in Rio Grande followed by Bahaushe with 1.50 µmolg-1. In conclusion, GB and Pro are osmoregulators produced by tomato in response to stress so as to alleviate the consequence effects of salt stress.


Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1255 ◽  
Author(s):  
Xiaojing Yu ◽  
Cang Hui ◽  
Hardev S. Sandhu ◽  
Zhiyi Lin ◽  
Peijian Shi

Leaf surface area (A) and leaf shape have been demonstrated to be closely correlated with photosynthetic rates. The scaling relationship between leaf biomass (both dry weight and fresh weight) and A has been widely studied. However, few studies have focused on the scaling relationship between leaf shape and A. Here, using more than 3600 leaves from 12 Rosaceae species, we examined the relationships of the leaf-shape indices including the left to right side leaf surface area ratio (AR), the ratio of leaf perimeter to leaf surface area (RPA), and the ratio of leaf width to length (RWL) versus A. We also tested whether there is a scaling relationship between leaf dry weight and A, and between PRA and A. There was no significant correlation between AR and A for each of the 12 species. Leaf area was also found to be independent of RWL because leaf width remained proportional to leaf length across the 12 species. However, there was a negative correlation between RPA and A. The scaling relationship between RPA and A held for each species, and the estimated scaling exponent of RPA versus A approached −1/2; the scaling relationship between leaf dry weight and A also held for each species, and 11 out of the 12 estimated scaling exponents of leaf dry weight versus A were greater than unity. Our results indicated that leaf surface area has a strong scaling relationship with leaf perimeter and also with leaf dry weight but has no relationship with leaf symmetry or RWL. Additionally, our results showed that leaf dry weight per unit area, which is usually associated with the photosynthetic capacity of plants, increases with an increasing A because the scaling exponent of leaf dry weight versus A is greater than unity. This suggests that a large leaf surface area requires more dry mass input to support the physical structure of the leaf.


2014 ◽  
Vol 32 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fánor Casierra-Posada ◽  
Esteban Zapata-Casierra ◽  
Daniel A. Chaparro-Chaparro

To determine the effects of light quality on the growth indices of plants, Pencas Blancas cultivar chard plantlets were grown for 2 months under five different light treatments, obtained by filtering sunlight through colored polyethylene films. The treatments included: red, blue, green, yellow and transparent cover colors. A transparent cover (white light) was used as the control. The colored covers affected the plant growth. The plants grown under the yellow cover presented a better behavior with regards to growth, taken as: total dry weight per plant, leaf area, specific leaf area, absolute growth rate, relative growth rate, harvestable dry matter and root to shoot ratio. The dry matter partitioning in the leaves and roots was affected by the light quality, but not in the petioles, with a higher accumulation of dry mass in the leaves of plants grown under the yellow cover. As a consequence of the enhanced leaf area in the plants under the yellow cover, they also had the highest water uptake. On the other hand, the highest net assimilation rate value was found in plants grown under the transparent cover. These results open up the possibility of using yellow colored cover in leafy green vegetables, especially in chard plants grown under controlled conditions.


2018 ◽  
Vol 39 (5) ◽  
pp. 1899 ◽  
Author(s):  
Gisele Silva de Aquino ◽  
João Gilberto Sampaio dos Santos ◽  
Tayna Gomes Diniz ◽  
Cristiane De Conti Medina ◽  
Raffaella Rosseto ◽  
...  

The sugarcane pre-sprouted seedlings (PSS) system is a new multiplication technology that contributes to the rapid production of seedlings and is associated with a high standard of vegetal health, vigour and uniformity of planting, as well as a drastic reduction in the use of seedlings per area. Due to the high moisture required during the initial period of growth, the filter cake can be an ally in the development of this technology. Thus, this work aimed to evaluate the development of sugarcane PSS, under different amounts of filter cake and application modes. The treatments included five doses of filter cake at 0, 7.5, 15, 30, and 45 t ha-1 and two forms of application: depth (0.30 m) and surface. Once formed, the sugarcane PPS were planted in Eutroferric Red Latosol, with due treatments. For aerial development analyses, leaf area, stem length and diameter and shoot dry mass were evaluated at 15, 30, 45, 60, 75 and 90 days after planting. The filter cake positively influenced the development of pre-sprouted seedlings, promoting greater leaf area and stalk diameter when applied on the surface. The dose of 30 t ha-1 to the surface, provided 54% higher shoot dry weight and 56% more dry weight of roots compared to cultivation without its application, demonstrating its usefulness to improve the development of pre-sprouted seedlings.


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