Plasticity tradeoffs in salt tolerance mechanisms among desert Distichlis spicata genotypes

2011 ◽  
Vol 38 (3) ◽  
pp. 187 ◽  
Author(s):  
Brynne E. Lazarus ◽  
James H. Richards ◽  
Phoebe E. Gordon ◽  
Lorence R. Oki ◽  
Corey S. Barnes
Keyword(s):  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Gender Segregation ◽  
Dust Control ◽  
Distichlis Spicata ◽  
Cellular Functions ◽  
Natural Habitats ◽  
Greenhouse Study ◽  
Dry Lake ◽  
Gender Based

We investigated genetic differences in salinity tolerance among 20 saltgrass (Distichlis spicata (L.) Greene) genotypes, including constitutive, gender-based and phenotypic plasticity traits, to better understand the basis of adaptation and acclimation by saltgrass in diverse environments. On average, the plants survived NaCl treatments up to ~1 M, with reductions in growth and health that varied with genotype. For these 20 genotypes in a greenhouse study, we showed that greater plasticity in one salt tolerance mechanism was physiologically linked to lesser plasticity in another. Under various levels of constant salinity stress, genotypes employing a strategy of greater plasticity in foliar Na and lesser plasticity in both foliar K : Na and Na turnover rate were better able to substitute Na for K in some cellular functions, especially osmotic adjustment, leading to increased salinity tolerance. Although we observed gender segregation with salinity in the Owens (Dry) Lake Playa (Inyo County, CA, USA) population planted for dust control, from which the genotypes were collected, we did not observe gender differences in salinity tolerance in the greenhouse. Significant physiological plasticity tradeoffs among genotypes, however, did affect overall salinity tolerance and may be important for this species survival in diverse managed and natural habitats.

Application of SSR Technique for the Identification of Markers Linked to Salinity Tolerance in Rice

2013 ◽  
Vol 19 (2) ◽  
pp. 57-65
Author(s):  
MH Kabir ◽  
MM Islam ◽  
SN Begum ◽  
AC Manidas
Keyword(s):  
Salt Tolerance ◽  
Ssr Markers ◽  
Salinity Tolerance ◽  
Seedling Stage ◽  
Phenotypic Screening ◽  
Salt Tolerant ◽  
Marker Assisted Breeding ◽  
Hydroponic System ◽  
Rice Landrace ◽  
Salt Susceptible

A cross was made between high yielding salt susceptible BINA variety (Binadhan-5) with salt tolerant rice landrace (Harkuch) to identify salt tolerant rice lines. Thirty six F3 rice lines of Binadhan-5 x Harkuch were tested for salinity tolerance at the seedling stage in hydroponic system using nutrient solution. In F3 population, six lines were found as salt tolerant and 10 lines were moderately tolerant based on phenotypic screening at the seedling stage. Twelve SSR markers were used for parental survey and among them three polymorphic SSR markers viz., OSR34, RM443 and RM169 were selected to evaluate 26 F3 rice lines for salt tolerance. With respect to marker OSR34, 15 lines were identified as salt tolerant, 9 lines were susceptible and 2 lines were heterozygous. While RM443 identified 3 tolerant, 14 susceptible and 9 heterozygous rice lines. Eight tolerant, 11 susceptible and 7 heterozygous lines were identified with the marker RM169. Thus the tested markers could be efficiently used for tagging salt tolerant genes in marker-assisted breeding programme.DOI: http://dx.doi.org/10.3329/pa.v19i2.16929 Progress. Agric. 19(2): 57 - 65, 2008

Implementasi Kebijakan “Segregasi” Kelas Berbasis Gender Di SMP Islam Al-Maarif 01 Singosari

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Nadzifatul Mu’tamaroh ◽  
Yuni Pantiwati
Keyword(s):  
Data Collection ◽  
Junior High School ◽  
Policy Process ◽  
Junior High ◽  
Gender Segregation ◽  
Male Students ◽  
Collection Data ◽  
Gender Based ◽  
Using Data ◽  
Guidance Teacher

Abstract: Gender issues must be resolved immediately. The study aims to describe: 1) Implementation of gender-based class segregation policies; 2) Inhibiting factors and solutions in implementing gender-based class segregation policies and school efforts in overcoming the problems faced in implementing gender-based class segregation policies. The type of research used is descriptive qualitative. This research was carried out at Islamic junior high school Maarif 01 Singosari. Data collection techniques are interviews, observation, and documentation. The analysis phase used is data collection, data reduction, data presentation, conclusion drawing. To check the validity of the data using data and source triangulation. The results showed that 1) The implementation of the gender-based class segregation policy process of its implementation was carried out by separating classes between male and female classes, from grades VII, VII and X but in one building, one organization and supported by the implementation of orderly. 2) Barriers and solutions faced by schools in carrying out policies are: attitudes of male students disagree with the existence of policies that have an impact on the class structure when learning hours are less conducive. The solution that is done by the school, by providing approaches and direction to students, and every teacher and especially the counseling guidance teacher and subject teachers must know all the problems that often occur to Al Maarif SMPI students to be evaluated on an ongoing basis.Keywords: Gender, Segregation, Policy Implementation Abstrak: Permasalahan mengenai gender harus segara dituntaskan.Tujuan penelitian ini adalah untuk mendeskripsikan: 1) Implementasi kebijakan segregasi kelas berbasis gender; 2) Faktor penghambatdan solusi dalam implementasi kebijakan segregasi kelas berbasis gender dan upaya sekolah dalam mengatasi masalah yang dihadapi dalam implementasi kebijakan segregasi kelas berbasis gender. Jenis penelitian yang digunakan adalah deskriptif kualitatif. Penelitian ini dilaksanakan di SMPIslamAl Maarif 01 Singosari. Teknik pengumpulan data yaitu Wawancara, observasi dan dokumentasi. Tahapan analisis yang digunakan yaitu pengumpulan data, reduksi data, penyajian data, penarikan kesimpulan. Untuk mengecek keabsahan data menggunakan triangulasi data dan sumber. Hasil penelitian menunjukkan bahwa 1) Implementasi kebijakan segregasi kelas berbasis gender proses penerapannya dilakukan dengan cara pemisahan kelas antara kelas laki-laki dan kelas perempuan, mulai dari kelas VII, VII dan X akan tetapi dalam satu gedung, satu organisasi dan didukung dengan diterapkannya tata tertib. 2) Kendala dan solusi yang dihadapi sekolah dalam menjalankan kebijakan yaitu: sikap siswa putra kurang setuju adanya kebijakan hal tersebut berdampak pada suasana kelas pada saat jam pembelajaran kurang kondusif. Solusi yang dilakukan sekolah, dengan memberikan pendekatan dan arahan terhadap siswa, dan setiap guru dan khususnya guru BK dan guru mata pelajaran harus mengetahui segala problem yang sering terjadi pada siswa Islamic junior high schoolAl Maarif untuk dievaluasi secara berkelanjutan.Kata kunci: Segregasi, Gender, Implementasi Kebijakan

scholarly journals Evaluation of salinity tolerance indices in North African barley accessions at reproductive stage

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
Dorsaf Allel ◽  
Anis BenAmar ◽  
Mounawer Badri ◽  
Chedly Abdelly
Keyword(s):  
Salt Tolerance ◽  
Grain Yield ◽  
Salinity Tolerance ◽  
Selection Criteria ◽  
Reproductive Stage ◽  
Shoot Biomass ◽  
Salt Tolerant ◽  
North African ◽  
Grain Number ◽  
Selection Indices

Soil salinity is one of the main factors limiting cereal productivity in worldwide agriculture. Exploitation of natural variation in local barley germplasm is an effective approach to overcome yield losses. Three gene pools of North African Hordeum vulgare L. grown in Tunisia, Algeria and Egypt were evaluated at the reproductive stage under control and saline conditions. Assessment of stress tolerance was monitored using morphological, yield-related traits and phenological parameters of reproductive organs showing significant genetic variation. High heritability and positive relationships were found suggesting that some traits associated with salt tolerance could be used as selection criteria. The phenotypic correlations revealed that vegetative traits including shoot biomass, tiller number and leaf number along with yield-related traits such as spike number, one spike dry weight, grain number/plant and grain number/spike were highly positively correlated with grain yield under saline conditions. Hence, these traits can be used as reliable selection criteria to improve barley grain yield. Keeping a higher shoot biomass and longer heading and maturity periods as well as privileged filling ability might contribute to higher grain production in barley and thus could be potential target traits in barley crop breeding toward improvement of salinity tolerance. Multiple selection indices revealed that salt tolerance trait index provided a better discrimination of barley landraces allowing selection of highly salt-tolerant and highly productive genotypes under severe salinity level. Effective evaluation of salt tolerance requires an integration of selection indices to successfully identify and characterize salt tolerant lines required for valuable exploitation in the management of salt-affected areas.  

scholarly journals Early Growth Stage Characterization and the Biochemical Responses for Salinity Stress in Tomato

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 712
Author(s):  
Md Sarowar Alam ◽  
Mark Tester ◽  
Gabriele Fiene ◽  
Magdi Ali Ahmed Mousa
Keyword(s):  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Salinity Treatment ◽  
Salt Tolerant ◽  
Improvement Program ◽  
Biochemical Basis ◽  
Elevated Salinity ◽  
Tolerance Indices ◽  
Promising Source ◽  
Tomato Genotypes

Salinity is one of the most significant environmental stresses for sustainable crop production in major arable lands of the globe. Thus, we conducted experiments with 27 tomato genotypes to screen for salinity tolerance at seedling stage, which were treated with non-salinized (S1) control (18.2 mM NaCl) and salinized (S2) (200 mM NaCl) irrigation water. In all genotypes, the elevated salinity treatment contributed to a major depression in morphological and physiological characteristics; however, a smaller decrease was found in certain tolerant genotypes. Principal component analyses (PCA) and clustering with percentage reduction in growth parameters and different salt tolerance indices classified the tomato accessions into five key clusters. In particular, the tolerant genotypes were assembled into one cluster. The growth and tolerance indices PCA also showed the order of salt-tolerance of the studied genotypes, where Saniora was the most tolerant genotype and P.Guyu was the most susceptible genotype. To investigate the possible biochemical basis for salt stress tolerance, we further characterized six tomato genotypes with varying levels of salinity tolerance. A higher increase in proline content, and antioxidants activities were observed for the salt-tolerant genotypes in comparison to the susceptible genotypes. Salt-tolerant genotypes identified in this work herald a promising source in the tomato improvement program or for grafting as scions with improved salinity tolerance in tomato.

scholarly journals Relative Salinity Tolerance of Turf-type Saltgrass Selections

HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Y.L. Qian ◽  
J.M. Fu ◽  
S.J. Wilhelm ◽  
D. Christensen ◽  
A.J. Koski
Keyword(s):  
Salt Tolerance ◽  
Culture System ◽  
Hydroponic Culture ◽  
Distichlis Spicata ◽  
Saline Soils ◽  
Salt Tolerant ◽  
Saline Irrigation ◽  
Turf Quality ◽  
Salinity Levels ◽  
Irrigation Waters

Salt-tolerant turfgrass is highly desirable in areas associated with saline soils or saline irrigation waters. To determine the salt tolerance of 14 saltgrass [Distichlis spicata var. stricta (Greene)] selections, two greenhouse studies were conducted by means of a hydroponic culture system. Five salinity levels (from 2 to 48 dS·m−1) were created with ocean salts. In general, turf quality decreased and leaf firing increased as salinity increased. However, varying levels of salt tolerance were observed among selections based on leaf firing, turf quality, root growth, and clipping yield. Selections COAZ-01, COAZ-18, CO-01, and COAZ-19 exhibited the best turf quality and the least leaf firing at 36 and 48 dS·m−1 salinity levels in both Experiments 1 and 2. At the highest salinity level (48 dS·m−1), COAZ-18 and COAZ-19 exhibited the highest root activity among all accessions. Salinity levels that caused 25% clipping reduction ranged from 21.2 to 29.9 dS·m−1 and were not significantly different among entries. The data on 25% clipping reduction salinity of saltgrass generated in this study rank saltgrass as one of the most salt-tolerant species that can be used as turf.

Use of EcoTILLING to identify natural allelic variants of rice candidate genes involved in salinity tolerance

2011 ◽  
Vol 9 (2) ◽  
pp. 300-304 ◽  
Author(s):  
S. Negrão ◽  
C. Almadanim ◽  
I. Pires ◽  
K. L. McNally ◽  
M. M. Oliveira
Keyword(s):  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Regulation Of Gene Expression ◽  
Cost Effective ◽  
Potential Contribution ◽  
Nucleotide Polymorphisms ◽  
Time Saving ◽  
Allelic Variants ◽  
Small Indels ◽  
Stress Signal

Rice is a salt-sensitive species with enormous genetic variation for salt tolerance hidden in its germplasm pool. The EcoTILLING technique allows us to assign haplotypes, thus reducing the number of accessions to be sequenced, becoming a cost-effective, time-saving and high-throughput method, ideal to be used in laboratories with limited financial resources. Aiming to find alleles associated with salinity tolerance, we are currently using the EcoTILLING technique to detect single nucleotide polymorphisms (SNPs) and small indels across 375 germplasm accessions representing the diversity available in domesticated rice. We are targeting several genes known to be involved in salt stress signal transduction (OsCPK17) or tolerance mechanisms (SalT). So far, we found a total of 15 and 23 representative SNPs or indels in OsCPK17 and SalT, respectively. These natural allelic variants are mostly located in 3′-untranslated region, thus opening a new path for studying their potential contribution to the regulation of gene expression and possible role in salt tolerance.

Glass Ceilings in Portugal?

2010 ◽  
Vol 1 (2) ◽  
pp. 1-18 ◽  
Author(s):  
Raquel Mendes
Keyword(s):  
Wage Inequality ◽  
Glass Ceiling ◽  
Gender Wage Gap ◽  
Wage Gap ◽  
Gender Segregation ◽  
Ceiling Effect ◽  
Wage Distribution ◽  
Women's Wages ◽  
Gender Based ◽  
Women's Role

Despite the evidence of female progress with regard to women’s role in the labor market, gender inequality remains. Women are still less likely to be employed than men, occupational gender segregation continues, and females continue to earn less than males. The gender wage gap remains wide in several occupational sectors, among which is the information technology (IT) sector. This paper focuses the determinants of gender wage inequality. More precisely, it investigates for statistical evidence of a glass ceiling effect on women’s wages. Based on the quantile regression framework, the empirical analysis extends the decomposition of the average gender wage gap to other parts of the earnings distribution. The main objective is to empirically test whether gender-based wage discrimination is greater among high paid employees, in line with glass ceiling hypothesis. Larger unexplained gaps at the top of the wage distribution indicate the existence of a glass ceiling effect in Portugal.

Matching physiological traits and ion concentrations associated with salt stress in cowpea genotypes

2002 ◽  
Vol 53 (11) ◽  
pp. 1243 ◽  
Author(s):  
Bernardo Murillo-Amadot ◽  
Enrique Troyo-Diéguez ◽  
Raúl López-Aguilar ◽  
Alejandro López-Cortés ◽  
Clara L. Tinoco-Ojanguri ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Growth Stage ◽  
Seedling Survival ◽  
Nutrient Deficiency ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Ion Concentrations ◽  
Survival Percentage

The salt tolerance of 25 cowpea genotypes (Vigna unguiculata L. Walp.) was studied during early vegetative growth. Salinity treatments were applied by irrigating with a nutrient solution containing 0, 85, and 170 mmol NaCl/L. Seedling survival decreased linearly as salinity increased, but this enabled cowpea genotypes to be ranked for salinity tolerance according to the magnitudes of slopes of regression of survival percentage on salinity. Sodium concentration was higher in roots than in shoots in all genotypes, and increased significantly in both roots and shoots as salinity increased. Chloride concentration in both roots and shoots increased with increasing salinity in all genotypes, and was higher in shoots than in roots at 85 and 170 mmol NaCl/L. In some cases, Ca, Mg, K, and P concentrations were reduced by an increase in salinity, but none of the genotypes appeared to suffer any nutrient deficiency. We observed wide differences in responses to salinity, and our results suggest that during the growth stage studied, 7 of the 25 genotppes tested could be classified as tolerant or relatively tolerant to salinity (Sonorense, CB3, CB27, Cuarenteño, CB46, Paceño, and IT82D-889).

scholarly journals Physiological and Biochemical Responses to Salt Stress of Alfalfa Populations Selected for Salinity Tolerance and Grown in Symbiosis with Salt-Tolerant Rhizobium

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 569
Author(s):  
Annick Bertrand ◽  
Craig Gatzke ◽  
Marie Bipfubusa ◽  
Vicky Lévesque ◽  
Francois P. Chalifour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Water Content ◽  
Salinity Tolerance ◽  
Osmotic Adjustment ◽  
Recurrent Selection ◽  
Aromatic Amino Acids ◽  
Nacl Stress ◽  
Salt Tolerant

Alfalfa and its rhizobial symbiont are sensitive to salinity. We compared the physiological responses of alfalfa populations inoculated with a salt-tolerant rhizobium strain, exposed to five NaCl concentrations (0, 20, 40, 80, or 160 mM NaCl). Two initial cultivars, Halo (H-TS0) and Bridgeview (B-TS0), and two populations obtained after three cycles of recurrent selection for salt tolerance (H-TS3 and B-TS3) were compared. Biomass, relative water content, carbohydrates, and amino acids concentrations in leaves and nodules were measured. The higher yield of TS3-populations than initial cultivars under salt stress showed the effectiveness of our selection method to improve salinity tolerance. Higher relative root water content in TS3 populations suggests that root osmotic adjustment is one of the mechanisms of salt tolerance. Higher concentrations of sucrose, pinitol, and amino acid in leaves and nodules under salt stress contributed to the osmotic adjustment in alfalfa. Cultivars differed in their response to recurrent selection: under a 160 mM NaCl-stress, aromatic amino acids and branched-chain amino acids (BCAAs) increased in nodules of B-ST3 as compared with B-TS0, while these accumulations were not observed in H-TS3. BCAAs are known to control bacteroid development and their accumulation under severe stress could have contributed to the high nodulation of B-TS3.

Halophilic rhizobacteria from Distichlis spicata promote growth and improve salt tolerance in heterologous plant hosts

Symbiosis ◽  
2017 ◽  
Vol 73 (3) ◽  
pp. 179-189 ◽  
Author(s):  
Rubén Palacio-Rodríguez ◽  
Jessica Lizbeth Coria-Arellano ◽  
José López-Bucio ◽  
Jaime Sánchez-Salas ◽  
Gisela Muro-Pérez ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Distichlis Spicata ◽  
Plant Hosts
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