The clonal grass Leymus chinensis overcomes salt stress by over-compensatory growth of individual ramets

2019 ◽  
Vol 70 (11) ◽  
pp. 1004 ◽  
Author(s):  
Congcong Zheng ◽  
Huimin Ma ◽  
Yingzhi Gao ◽  
Hao Sun ◽  
Haijun Yang ◽  
...  

Soil salinisation and overgrazing are two important factors limiting plant growth in the Songnen Grassland, Northeast China. Leymus chinensis, a dominant rhizomatous grass, resists grazing and tolerates saline–alkali stress. However, its adaptive mechanisms to the dual effects of grazing and saline–alkali stress remain largely unknown. A two-factorial field experiment was conducted in two consecutive years in the natural L. chinensis community, combining the addition of mixed saline–alkali solution (NaCl:NaHCO3:Na2CO3 1:1:1, amount 559.13 g m–2 year–1) with clipping (removal of 60% of aboveground biomass, AGB). Saline–alkali addition significantly increased AGB and total biomass in the no clipping but not in the clipping treatment. Irrespective of clipping, ramet density was significantly decreased, and individual ramet biomass was significantly increased under salt stress. The significant increase in AGB was due to a high K+:Na+ ratio, high water-use efficiency, and an increase in leaf area index and net photosynthesis rate of individual ramets under salt–alkali stress. Clipping significantly decreased AGB and total biomass regardless of saline–alkali addition, possibly because of decreased sugar content of rhizomes. Saline–alkali and clipping had an interactive effect on AGB and total biomass of L. chinensis. The significant reduction in AGB and total biomass were mainly caused by reduced proline and water-soluble carbohydrate content under dual stress. A modified and simplified graphic model of the limiting resource model was proposed based on our results. Leymus chinensis can grow well under saline–alkali stress via ramet biomass compensation, in which the significant decrease in ramet density is compensated by the significant increase in individual ramet biomass. Ramet compensation and clonal integration were identified to be main mechanisms of herbivory and saline–alkali tolerance.

2019 ◽  
Vol 5 ◽  
pp. 11-15
Author(s):  
Remy Manderscheid ◽  
Cathleen Frühauf ◽  
Andreas Pacholski ◽  
Hans Joachim Weigel

Sugar beet was grown within a crop rotation over two rotation cycles (2001, 2004) at ambient and elevated atmospheric CO2 concentration (375 and 550 ppm) with practical (126, 156 kg N ha-1) and low levels (63, 78 kg N ha-1) of nitrogen supply. In the second year another cultivar was used to prevent infestation by rhizomania, which occured on one half of the field plots at the end of the season of 2001. In 2004, shading was included as an additional treatment. The objectives were to investigate the growth response of sugar beet to elevated CO2 concentration at high and low nitrogen availability. Data set includes data on management, soil condition, weather, below and above ground growth (individual leaves, leaf area index, total biomass, beet yield and composition, water soluble carbohydrates, root biomass).


2014 ◽  
Vol 1010-1012 ◽  
pp. 1225-1229
Author(s):  
Ming Xia Zhu ◽  
Feng Jin ◽  
Xi Wen Shao ◽  
Xian Ying Gao ◽  
Yan Qiu Geng ◽  
...  

Taking Changbai 9 and Changbai 22 as experiment material, using pot experiment, to study of different concentration effect of saline alkali stress on physiological characteristics of rice in different growth periods. The results showed that, effect of saline alkali stress on the physiological characteristics of the same rice variety and soil characteristics of different resistant rice varieties are different. Weak salt resistance of Changbai 22 of chlorophyll , soluble sugar and MDA of salt stress more sensitive than saline resistance strong of Changbai 9,and the change trend of the physiological indexes of two cultivars under saline alkali stress is consistent, with the increasing concentration of salt stress, leaf chlorophyll content, soluble sugar content and soluble protein content firstly increased and then decreased,while the MDA concentration showed an increasing trend. At the same time with the increase of salt stress concentration, accumulation of soluble sugar in leaves of Changbai 9 increased even more than Changbai 22,indicating the Changbai 9 may be mainly through the accumulation of soluble sugar to alleviate the toxic effects of osmotic stress. This study can be used as an important reference index for soda saline alkali soil rice planting, soil improvement and comprehensive utilization.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Hongna ◽  
Shi Junmei ◽  
Tao Leyuan ◽  
Han Xiaori ◽  
Lin Guolin ◽  
...  

Spermidine (Spd) is known to protect macromolecules involved in physiological and biochemical processes in plants. However, it is possible that Spd also plays an osmotic regulatory role in promoting the seed germination of Leymus chinensis (L. chinensis) under salt-alkali stress. To investigate this further, seeds of L. chinensis were soaked in Spd solution or distilled water, and a culture experiment was performed by sowing the soaked seeds in saline-alkaline soils. The data showed that the Spd priming resulted in an increase of more than 50% in soluble sugar content and an increase of more than 30% in proline content in the germinating seeds. In addition, the Spd priming resulted in an increase of more than 30% in catalase activity and an increase of more than 25% in peroxidase activity in the germinating seeds and effectively mitigated the oxidative damage to the plasma membrane in the germinating seeds under salt-alkali stress. Moreover, the Spd priming of seeds affected the accumulation of polyamine (PA) and maintained the activities of macromolecules involved in physiological metabolism in germinating seeds exposed to salt-alkali stress. Furthermore, the Spd priming treatment increased the hydrogen peroxide (H2O2) level to more than 30% and the Ca2+ concentration to more than 20% in the germinating seeds, thus breaking the dormancy induction pathways in L. chinensis seeds through beneficial hormone enrichment. This study provides an insight into the Spd-mediated regulation pathway during exogenous Spd priming of L. chinensis seeds, which mitigates osmotic and oxidative damage and maintains the integrality of the cell lipid membrane. Thus, exogenous Spd priming increases PA oxidase activity and maintains the accumulation of H2O2. We found that the H2O2 beneficially affected the balance of Ca2+ and hormones, promoting the vigor and germination of L. chinensis in response to salt-alkali stress.


Author(s):  
Ni Putu Diah Cahyani Subamia ◽  
Komang Ayu Nocianitri ◽  
I Dewa Gede Mayun Permana

Type II diabetes mellitus due to an unhealthy lifestyle, one of which is the lack of fiber in daily food consumption. One food that has a high fiber content is tofu dregs. The purpose of this study was to determine substitution of wheat flour with tofu dregs flour to produce a snack bar with the best characteristics, and determine the effect of consumption of snack bar from tofu dregs on blood sugar content in rats. The research was conducted two steps. Step I: Formulation of snack bar using a completely randomized design with tofu dregs flour concentration of 0 %, 10 %, 20 %, 30 %, 40 %, and 50 %. The variables of this study were the content of water, ash, protein, fat, carbohydrates, sensory tests, and effectiveness tests. Step II: the best characteristic snack bar in the step I was used experimental rats. This step used true experimental design with pre-post test control group design. The variables of study were blood glucose levels before treatment and after treatment. The treatment group consisted of normal, negative, positive control, and snack bar. The results of the first step of the research showed that substitution of wheat flour with 40 % tofu dregs produced the best characteristic snack bar with 17.19 % water content, 1.33 % ash content, 11.03 % protein, 20.53 % fat, 49.92 % carbohydrate, light brown color, unpleasant aroma, distinctive soy taste, crumb texture, 0.63 % water soluble food fiber, 1.57 % water insoluble fiber, and total food fiber 2.36 %. The results of the second step of the study showed that the provision of substitution of wheat flour with tofu dregs flour 40 % could reduce blood sugar levels in diabetic mellitus rats until normal, start 290 mg/dl to 108.5 mg/dl. Tofu dregs flour can be used for snack bar formulations for people with diabetes mellitus.


2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.


2021 ◽  
pp. 1-10
Author(s):  
Min Huang ◽  
Zui Tao ◽  
Tao Lei ◽  
Fangbo Cao ◽  
Jiana Chen ◽  
...  

Summary The development of high-yielding, short-duration super-rice hybrids is important for ensuring food security in China where multiple cropping is widely practiced and large-scale farming has gradually emerged. In this study, field experiments were conducted over 3 years to identify the yield formation characteristics in the shorter-duration (∼120 days) super-rice hybrid ‘Guiliangyou 2’ (G2) by comparing it with the longer-duration (∼130 days) super-rice hybrid ‘Y-liangyou 1’ (Y1). The results showed that G2 had a shorter pre-heading growth duration and consequently a shorter total growth duration compared to Y1. Compared to Y1, G2 had lower total biomass production that resulted from lower daily solar radiation, apparent radiation use efficiency (RUE), crop growth rate (CGR), and biomass production during the pre-heading period, but the grain yield was not significantly lower than that of Y1 because it was compensated for by the higher harvest index that resulted from slower leaf senescence (i.e., slower decline in leaf area index during the post-heading period) and higher RUE, CGR, and biomass production during the post-heading period. Our findings suggest that it is feasible to reduce the dependence of yield formation on growth duration to a certain extent in rice by increasing the use efficiency of solar radiation through crop improvement and also highlight the need for a greater fundamental understanding of the physiological processes involved in the higher use efficiency of solar radiation in super-rice hybrids.


1974 ◽  
Vol 14 (68) ◽  
pp. 343 ◽  
Author(s):  
RJ Jones

Experiments with Siratro were conducted at Samford, south east Queensland to study the effects of previous cutting and defoliation treatments on regrowth. In the first experiment, swards of Siratro were cut at 7.5 cm above ground level every 4 weeks, every 8 weeks or cut once at 16 weeks during spring and summer. Regrowth of all treatments over ten weeks was measured after varying (by leaf removal) the stubble leaf area index (LAI) of the plots cut every four weeks. Pattern of regrowth yield was similar for all treatments with a pronounced lag phase after cutting. Regrowth yield after 10 weeks differed between treatments and was linearly related (P < 0.01 ) to residual LAI in the stubble at the start of regrowth. In the absence of stubble leaves, plots previously cut at 16 weeks or at 8 weeks yielded marginally more than those cut every 4 weeks. There were no marked treatment differences in gross root morphology other than a two fold increase in stolon rooting for the 16-week treatment. Nitrogen content of the roots (mean 1.38 per cent) was unaffected by treatment, but the per cent hot water soluble sugars were lower for the 16 week defoliation treatment than for the 8-week and the 4-week treatments. In the second experiment individual plants were cut to a uniform stubble every 4 weeks and either 0, 5, or 10 leaves were left. Dry weight of regrowth and stolon development were greatest when most leaves were left. Two thirds of the plants died after six cuttings with complete defoliation but none died when either 5 or 10 leaves were retained. Plant survival was not related to plant yield or degree of stoloniferous development. However, there was a strong correlation between stolon number and plant yield under this intensive cutting regime. The practical implication of the results in the management of Siratro is discussed.


2016 ◽  
Vol 76 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Shakeel Ahmad Anjum ◽  
Jin-huan Li ◽  
Jun Lv ◽  
Xue-feng Zong ◽  
Ling Wang ◽  
...  

2021 ◽  
Vol 108 (september) ◽  
Author(s):  
Varshini S V ◽  
◽  
Jayanthi C ◽  

A field experiment was conducted at the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore, to study the influence of sett treatment on biochemical parameters, weed parameters, physiological parameters and nutrient uptake of bajra Napier hybrid grass. The results of the experiment indicated that on biochemical parameters, sett treatment with water (12 hours soaking fb 24 hours incubation) (S1) recorded higher reducing sugars (28.89 mg/g), total sugar (34.83 mg/g) and starch content (45.83 mg/g). Whereas the lower non reducing sugar content (5.94 mg/g) and total phenolics content (1.65 mg/g) were also observed with sett treatment with water (12 hours soaking fb 24 hours incubation) (S1). Similarly, on weed parameters, significantly lower weed density (9.90 No./m2) and weed dry weight (12.92 g/m2) was recorded with sett treatment with water (12 hours soaking fb 24 hours incubation) (S1). On physiological parameters, significantly higher leaf area index (28.98), relative water content (87.85 %) was registered with water (12 hours soaking fb24 hours incubation) (S1). Among sett treatments, water (12 hours soaking fb24 hours incubation) (S1) had registered higher nitrogen (192.8 kg ha-1), phosphorus (33.0 kg ha-1) and potassium (112.9 kg ha-1) uptake.


Author(s):  
Titus Fondo Ambebe ◽  
Anjah Grace Mendi ◽  
Abubakar Ali Shidiki

To investigate the effect of artificial defoliation and N availability on growth of Gmelina arborea, seedlings were subjected to three artificial defoliation levels (0, 25, 50%) and four N regimes (unfertilized, 1 g N plant-1, 3 g N plant-1, 6 g N plant-1) in a field trial. The results showed that height increment was 24.09% lower in the 50% defoliation than the undefoliated and 25% defoliation treatments which were not significantly different from each other. On average, the 25% and 50% defoliation treatments reduced stem volume increment by 44.34%. Increments of diameter and biomass and leaf production were not reduced by defoliation. In terms of response to N, increments in height and stem volume rose from 8.98 cm and 8.23 mm at unfertilized  to 11.39 cm and 12.13 mm at 3 g N plant-1, respectively, while number of new leaves increased by a margin of 1.51 from unfertilized to  6 g N plant-1. Total biomass increment that was unaffected by defoliation showed an increasing trend from 0.55 g at unfertilized and 1 g N to 0.83 g at 3 g N and 0.94 g at 6 g N plant-1. There was no significant interactive effect of treatments on any parameter, suggesting that the adverse effect of defoliation on growth of G. arborea seedlings may not be alleviated by N fertilization. It is encouraged that a similar study be conducted for a longer duration to ascertain if the responses are sustained or modified.


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