Structural Study of Microporous Xerogels Prepared by Polycondensation of Pyrogallol with Formaldehyde

Microporous xerogels were prepared by polycondensation of pyrogallol with formaldehyde catalyzed by perchloric acid in aqueous medium. The samples were characterized by FTIR absorption spectra. The micro-porosity and the specific surface area are characterized by nitrogen adsorption - desorption isotherms. The obtained characteristics depend on the conditions of polycondensation

EFFECT OF SALINITY STRESS ON GERMINATION OF FIVE TUNISIAN LENTIL (LENS CULINARIS L.) GENOTYPES

Salinity is one of the major stresses especially in arid and semi-arid regions, which severely limites crop production. It is a significant problem affecting agriculture worldwide and is predicted to become a larger problem in the coming decades. This study was conducted to assess the effect of different salinity level (0, 50, 150, 250 mMol of NaCl) on lentil seed germination efficiency (germination, seedling shoot length, seedling root length, seedling fresh shoot weight and seedling fresh root weight). Five Tunisian genotypes of lentil (Lens culinaris M) namely: Kef, Siliana, Nefza, Ncir, and Local oueslatia were investigated. Results showed that there were significant differences among the different NaCl solution for all evaluated traits. Indeed, the experiment showed that the concentrations of salt have a negative impact on the germination and growth of lentil. As a result when the concentration of salt increases, the germination, length of root and shoot and fresh weight of root and shoot decreases. At 250 mM salt stress level, seed germination percentage of all genotypes was notably reduced compared with non-stress condition (0.0 mMol). Moreover, the seeds were not germinated by the 250 mM salinity level for kef genotype. From the results of this present investigation, it can be concluded that seeds of Kef and Ncir genotypes were susceptible to higher concentrations of salt solutions in germination stage. However, Siliana, Local oueslatia and Nefza genotypes can be considered as tolerant to salt stress compared to the other ones. These genotypes could be used for further analysis and for hybridization in the breeding program for enhancing lentil cultivation in newly reclaimed soils

EFFECT OF SALINITY STRESS ON GERMINATION OF FIVE TUNISIAN LENTIL (LENS CULINARIS L.) GENOTYPES

Salinity is one of the major stresses especially in arid and semi-arid regions, which severely limites crop production. It is a significant problem affecting agriculture worldwide and is predicted to become a larger problem in the coming decades. This study was conducted to assess the effect of different salinity level (0, 50, 150, 250 mMol of NaCl) on lentil seed germination efficiency (germination, seedling shoot length, seedling root length, seedling fresh shoot weight and seedling fresh root weight). Five Tunisian genotypes of lentil (Lens culinaris M) namely: Kef, Siliana, Nefza, Ncir, and Local oueslatia were investigated. Results showed that there were significant differences among the different NaCl solution for all evaluated traits. Indeed, the experiment showed that the concentrations of salt have a negative impact on the germination and growth of lentil. As a result when the concentration of salt increases, the germination, length of root and shoot and fresh weight of root and shoot decreases. At 250 mM salt stress level, seed germination percentage of all genotypes was notably reduced compared with non-stress condition (0.0 mMol). Moreover, the seeds were not germinated by the 250 mM salinity level for kef genotype. From the results of this present investigation, it can be concluded that seeds of Kef and Ncir genotypes were susceptible to higher concentrations of salt solutions in germination stage. However, Siliana, Local oueslatia and Nefza genotypes can be considered as tolerant to salt stress compared to the other ones. These genotypes could be used for further analysis and for hybridization in the breeding program for enhancing lentil cultivation in newly reclaimed soils

Assessment Of Adaptability And Stability Of Six Tunisian Cereal Genotypes Under Rainfed Conditions And At Two Semi Arid Environments

Three durum wheat (Nasr, Maâli and Salim), two bread wheat (Tahent and Utique) and two barley varieties (Manel and Kounouz) were assessed in two different semi arid locations under rainfed conditions in 2012-2013 growing season for yield related traits performances, stability and adaptability parameters. For determining adaptability and stability of genotypes, regression coefficient (bi) and variance of deviation from regression (S²di) are used. The evaluation was based on five agro-morphological traits: tiller number/plant, spike number/m2, plant number/m2, 1000 kernel weight and grain number/ spike. Variance analysis indicated a highly significant (p<0.05) effect of locations and genotypes for all studied traits. Also, the interaction between the genotypes and environments found to be highly significant (p<0.001) for all studied traits except the tiller number/plant. Analysis of stability showed that there were differences in stability performances among the genotypes for the traits tested. The unstability for spike number/m², plant number/m 2, 1000kernel weight and grain number/spike among the genotypes was originated from the high mean squares of deviation from regression. Analysis of AMMI model showed that Principal Components (PC) Analysis indicated that the two PCs explained 78.17% (PC1 = 41.51% and PC2 = 36.66%) of the total variation. Results showed that the group of genotypes Nasr, Tahent, Kounouz and Manel having wide adaptability and could be recommended for cultivation across diverse environments

Pistacia vera L. leaves as a renewable source of bioactive compounds via microwave assisted extraction

The production of pistachio in Tunisia generates a large amount of potentially valuable waste, such as leaves, that could be used as source of bioactive compounds. In this work, the extraction of phytochemicals from Pistacia vera L. leaves (male and female) by microwave-assisted extraction (MAE) has been investigated. A response surface methodology (RSM) was used for the optimization of bioactive compounds extraction, where the independent variables were temperature and extraction time, and the dependent variable was extraction yield. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, and FRAP) and antimicrobial activity of the extracts obtained at optimal conditions for both leaves were evaluated and compared not only between them, but also with the extracts obtained by maceration. The optimum extraction conditions were 70 ? and 61 ?, and 5.6 and 12 min for male and female leaves respectivily. The best results were achieved for female leaves by MAE with 36% of extraction yield, TPC of 196.35 mg gallic acid equivalents (GAE)/g dry weight (DW), TFC of 83.34 mg catechin equivalents (CE)/g dry weight (DW), and high antioxidant and antimicrobial activities. The evaluation of biological activity of the extracts showed that MAE provides extracts with better antioxidant and antimicrobial capacities then those obtained by maceration. More-over, UPLC-DAD-ESI-MS was performed to confirm the presence of some phenolic compounds in MAE extracts, such as quercetin, apigenin and myricetin derivatives. The results revealed that MAE is an efficient technique for the extraction of active components from Pistacia vera L. leaves.The authors greatly acknowledge the financial support of the Ministry of Higher Education and Scientific Research of Tunisia. L.S. would like to thank to the Spanish Ministry of Universities for the Margarita Salas fellowship for the requalification of the Spanish university system financed by the European Union -Next GenerationEU

Yield of Durum Wheat Cultivar Grown under Different Nitrogen Regimes and Rainfed Conditions

The experiment was conducted in randomized complete block design with three replications in two different locations (Kef and Bousselem). The effect of four nitrogen treatments (0, 75, 100, 120 and 140 kg/ha of N) was assessed for Maali durum wheat variety on five agronomic traits: biological yield, grain yield, harvest index, 1000 kernel weight and nitrogen use efficiency. Analysis of variance revealed significant effect (P< 0.01; P< 0.001) of the nitrogen treatments for all studied traits. However, no nitrogen treatment x site interaction was noted. Except for nitrogen use efficiency, both location exhibited significant variation (p<0.01) for all the traits examined. Biological yield, grain yield, harvest index, 1000 kernel weight and nitrogen use efficiency increased with an increase in nitrogen levels. In comparison to kef site, greatest results were obtained in Bousselem site under all nitrogen levels for all measured traits. Maximum average yield (2157.27 kg/ha) and (3013.11 kg /ha) was unregistered under N4 treatment (140 kg/ha) in Kef and Boussalem site respectively. A significant and positive correlation was noted between nitrogen rates and biological yield (r = 0.74**), grain yield (r = 0.66**), harvest index (r = 0.84**) and 1000 kernel weight (r = 0.85**). In this region, it seems that the application of 140 kg/ha of N fertilization lead to great agronomic performance of Maali durum wheat variety

GENETIC DIVERSITY OF FABA BEAN (VICIA FABA L.) POPULATIONS ESTIMATED BY ISOZYMIC AND MOLECULAR MARKERS: RELATIONSHIP BETWEEN THE TWO METHODS

In our previous studies, the genetic diversity among nine Tunisian faba bean (Vicia faba) populations was analysed using isozymes and sequence-specific amplification polymorphism (SSAP) markers. The objectives of this study were to compare the application and utility of isozymes and sequence-specific amplification polymorphism (SSAP) techniques for analysis of genetic diversity among nine Tunisian faba bean (Vicia faba) populations. A high genetic diversity within populations was detected by both isozymes (SOD, 6-PGD, ME, EST, SKDH, FDH and GDH) and (SSAP) markers (PDR1, Tps19 and Tvf4). For all populations, the genetic diversity revealed by SSAP was more pronounced than that detected with isozyme, based on polymorphic profiles. The analyses of correspondance between the tow methodes based in Mantel test revealed a low correlation ( r=0.177). The low correspondance indicated the absence of correlation and therfore the complimentarit

Marker-Trait Associations of Agronomic Traits in Barley (<i>Hordeum vulgare</i> L.) under Semi-Arid Conditions

Heading date, plant height, and spike-related phenotypes are key traits that affect the yield potential and adaptation of barley to Mediterranean environments. These traits are controlled by a complex network of genes as well as environmental effects. Marker-trait associations (MTAs) were performed using a set of 361 barley genotypes, evaluated phenotypically for three years under semi-arid conditions. In total, 24 MTAs were detected using the recently developed GWAS method (BLINK) at –log p ≥ 5. These included one MTA with awn length (Awl) on chromosome 2H; twelve MTAs with heading date (HD) distributed over all chromosomes except 4H; three MTAs with grains per spike (GPS) on chromosomes 1H, 2H, and 6H; six MTAs were detected for plant height (PH) on 2H (2), 3H, 4H, 6H, and 7H; and two MTAs with spike length (SL) on 3H and 7H. The results showed novel and known associations between specific SNP markers and heading date, plant height, and spike-related traits, suggesting that these markers can be used in breeding programs to improve these traits in barley. This study provides valuable information for breeders and geneticists working to develop new barley varieties that are better adapted to semi-arid climates and have improved yield and quality characteristics