Authors:A.I.T. Shayanowako, H. Shimelis, M.D. Laing, and L. Mwadzingeni
Genetic diversity among breeding populations is key in plant breeding programs. This study aimed to determine the extent of genetic diversity among 37 diverse maize genotypes using simple sequence repeat (SSR) markers. The maize genotypes were selected based on their variable resistance to Striga asiatica. Maize genotypes were fingerprinted using 18 polymorphic SSR markers. Marker and population diversity parameters were computed. A total of 191 alleles were detected and the number of effective alleles varied from 2 to 21 per locus with a mean of 11. The polymorphic information content (PIC) of the SSR markers varied from 0.59 to 0.96, with a mean of 0.80. Significant differences were observed among populations, individuals and within individuals. Within and among individual variances accounted for 85% and 13% of the total gene diversity. The genotypes were grouped into three main genetic clusters, which were not influenced by genotype origin. Mean genetic distance (0.43) and low geneflow (0.18) were observed among the populations. High mean genetic identity (0.65) was recorded, indicating potential genetic ‘bottleneck’ among the selected germplasm. The following open pollinated varieties; Border King, Colorado, CIMMYT’s ZM OPVs, Mac Pearl, Shesha, Nel Choice, Natal 8Lines, Nel Choice QPM, Hickory King, Kep Select, Obatanpa and the Striga resistant synthetic variety DSTRYSYN15 were selected from different clusters for breeding.
Authors:Hermínio Digo, Susana Pinto, and Joaquim Moura Ramos
The thermal behaviour of salicylsalicylic acid (CAS number 552-94-3) was studied by differential scanning calorimetry (DSC).
The endothermic melting peak and the fingerprint of the glass transition were characterised at a heating rate of 10C min-1. The melting peak showed an onset at Ton = 144C (417 K) and a maximum intensity at Tmax = 152C (425 K), while the onset of the glass transition signal was at Ton = 6C. The melting enthalpy was found to be ΔmH = 28.90.3 kJ mol-1, and the heat capacity jump at the glass transition was ΔCP = 108.10.1 J K-1mol-1. The study of the influence of the heating rate on the temperature location of the glass transition signal by DSC, allowed
the determination of the activation energy at the glass transition temperature (245 kJ mol-1), and the calculation of the fragility index of salicyl salicylate (m = 45). Finally, the standard molar enthalpy of formation of crystalline monoclinic salicylsalicylic acid at T = 298.15 K, was determined as ΔfHmo(C14H10O5, cr) = - (837.63.3) kJ mol-1, by combustion calorimetry.
Authors:A. shahnejat Bushehri, A. Salavati, B. yazdi Samadi, M. Hassani, and S. Shahnejat Bushehri
A collection of new and obsolete Iranian bread wheat cultivars were characterized for gliadins using acid polyacrylamide gel electrophoresis (A-PAGE). Extensive polymorphism (H) = 0.734 in gliadin patterns was found. A total of 26 band patterns including 13, 8 and 5 different mobility bands were identified, in the zones of ω-, β + γ- and α-gliadins, respectively. There were a few patterns specific to each region and some were common among all the regions. Patterns of α-gliadin C, β + γ-gliadins A, and ω-gliadins H, C and E patterns were significantly higher in temperate and tropical zones. β + γ-gliadin C and ω-gliadin Q were significantly higher in Caspian-cold regions. Variation was observed in gliadins patterns of cultivars grown in different regions in Iran. Individual cultivars showed unique gliadin fingerprints. There were larger variation in ω- and γ + β-gliadins than in α-gliadins. These results may provide complementary information for relating genetic diversity, and quality characterization of Iranian wheat cultivars.
Authors:A. Bellatreche, S.R. Mnasri, M. Ben Naceur, and S.S.B. Gaouar
Climate change has significantly affected wheat yield. Many studies have suggested that rising temperatures could be harmful to cereals around the world. Thus, the valorization of the desert wheat resources is essential to improve the resistance of this species to climate change. In this context, twenty-eight different local Saharan bread wheat (Triticumaestivum L.) genotypes were described using ten preselected SSR markers. The tested SSRs produced a total number of 20 alleles with an allelic size ranged from 100 pb (WMC261) to 400 pb (WMC257). The allele frequency varied from 0.1 for the allele 230 pb (WMC156) to 1 for the alleles 187 pb, 310 pb (WMC97, WMC168). Likewise, the PIC values ranged from 0 (WMC97, WMC168) to 0.5 (WMC327, WMC233), with an average of 0.34 and the observed heterozygosity (Ho) from 0 to 0.88, with an average of 0.55. The molecular variance (AMOVA) revealed the highest level of intra-population differentiation of local Saharan bread wheat (97%) and the statistical geometric distributions based on PCoA, NJ method and structure analysis confirmed the existence of four major classes of bread wheat. These results substantiate the previous researches based on the morphological markers and contribute for the first time in Algeria to create the genetic fingerprint of the Saharan bread wheat resources and to valorize their drought resistance potential through breeding programs.
Authors:Renuka S. Joshi, Shubhada A. Tamhankar, and Anuradha S. Upadhye
An ingredient of ‘Dasamoola’ and ‘Laghupanchamoola’ group of drugs, the source of ‘Brihati’ has been controversial. Although the dried root of Solanum anguivi is considered as the source of the drug ‘Brihati’ according to the Ayurvedic Pharmacopoeia of India, closely related and morphologically similar few species like Solanum torvum, Solanum melongena, Solanum incanum, and Solanum insanum are known as its substitutes. In the present study, a high-performance thin-layer chromatography (HPTLC) method was developed and validated for the chemoprofiling and quantitative estimation of glycoalkaloid solamargine from 5 species of the genus Solanum as well as market samples. The developed method was precise, accurate, robust, specific, and linear. The results showed that S. incanum has the highest content of solamargine, followed by S. insanum. Out of the 9 market samples analyzed, solamargine was detected only in 3 samples. Unsupervised pattern recognition techniques, such as principal component analysis and hierarchical cluster analysis, were used to analyze the complex fingerprint patterns and to predict the grouping of samples. The method clearly segregated the field and market samples. Our study is the first attempt to evaluate the drug ‘Brihati’ and the market samples using HPTLC.
On the basis of the measured time-dependent distribution of references in recent scientific publications, we formulate a novel model on the ageing of recent scientific literature. The framework of this model is given by a basic set of mathematical expressions that allows us to understand and describe large-scale growth and ageing processes in science over a long period of time. In addition, a further and striking consequence results in a self- consistent way from our model. After the Scientific Revolution in 16th century Europe, the 'Scientific Evolution' begins, and the driving processes growth and ageing unavoidably lead - just as in our biological evolution - to a fractal differentiation of science. A fractal structure means a system build up with sub-systems characterised by a power-law size distribution. Such a distribution implies that there is no preference of size or scale. Often this phenomenon is regarded as a fingerprint of self-organisation. These findings are in agreement with earlier empirical findings concerning the clustering of scientific literature. Our observations reinforce the idea of science as a complex, largely self-organising 'cognitive eco-system'. They also refute Kuhn's paradigm model of scientific development.
Authors:K. Shanker, M. Singh, V. Srivastava, R. K. Verma, A. K. Gupta, and M. M. Gupta
An online-hyphenated high-performance liquid chromatography-photodiode array-mass spectrometry (HPLC-PDA-MS) analytical method was developed for the simultaneous determination of six lignans of therapeutic importance in four Phyllanthus spp. (P. amarus, P. maderaspatensis, P. urinaria, and P. virgatus). HPLC with monolithic reverse phase silica column (4.6 × 100 mm) and simple isocratic elution of methanol-water mixed with dioxane facilitated the separation of lignans of diverse nature such as diarylbutyrolactone, tetrahydrofuran, isomeric aryltetralin, and diarylbutane type for quantitative analysis. Targeted lignans viz. heliobuphthalmin lactone (1), virgatusin (2), hypophyllanthin (3), phyllanthin (4), nirtetralin (5), and niranthin (6) were confirmed unambiguously in four Phyllanthus species by their abundant molecular adduct ions, retention time, UV, and mass spectra as compared with those of reference compounds. Advantages and limitations of both detection techniques for qualitative (fingerprinting) and quantitative analysis of the above mentioned lignans in four Phyllanthus spp. are discussed. The method was validated following international guidelines. The described method can be utilized for assays and stability tests of P. amarus extracts as well as traditional Indian medicine based on Phyllanthus herb.
Authors:Richa Tyagi, Ekta Menghani, and Gaurav Sharma
Plumbago zeylanica L. (PZ) is a significant medicinal plant in Ayurveda, so is used for the treatment of various disorders. The main active part of this plant is the root, and due to its inherent uses, it has been exploited hence becoming an endangered species. Dyerophytum indicum (Gibbs ex Wight) Kuntze (DI), mainly considered as a substitute of PZ, is also an important folklore medicine, used in many health problems. Both plants are much similar in their physical as well as chemical properties. However, an effective validation is required before declaration of substitution. In the present study, quantitative and qualitative estimations were performed on both plants with the help of modern analytical techniques. Simultaneous high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) and quantitative determinations of β-sitosterol have been performed for comparing both plants, i.e., PZ and DI. HPTLC fingerprinting analysis was also performed comparatively in different plant parts of PZ and DI. Successive extracts from different plant parts were evaluated for TLC separation profile of secondary metabolites. A comparative polyphenolic content- and antioxidant screening was evaluated to check the free radical scavenging effect of both plants (leaf, stem, and root) in comparison with the standards gallic and ascorbic acid.
Authors:Denni Mammen, Mammen Daniel, and Ramesh Sane
Aerva lanata collected during summer, monsoon and winter were subjected to similar extraction conditions as well as sample application conditions on precoated silica 60F254 TLC plates. The plates were developed in ethyl acetate-toluene (7:3 v/v) in order to study the seasonal variation in HPTLC fingerprints. A similar procedure was also followed for the plant samples collected from three different states of India, in order to study the geographical variation. p-Hydroxybenzoic acid, used as reference standard for comparison with each sample, was observed in samples collected in all three seasons but in different concentrations. The compound was also observed in samples collected from Gujarat and Maharashtra, but was found to be absent in the sample from Kerala. The sample from Kerala showed a different compound at RF 0.74, having a λmax of 280 nm. This compound exhibited a spectrum very different from that of p-hydroxybenzoic acid having a λmax of 252 nm, which separates out at RF 0.73 on the plate. The proposed method was validated according to ICH guidelines in terms of linearity, accuracy and specificity, intra-day and inter-day precision, repeatability of measurement of peak area, repeatability of sample application and specificity. The calibration graph was found to be linear over a range of concentration of 25.0–175.0 ng, with a regression coefficient of 0.9986. Determination of accuracy by standard addition method at three different concentration levels returned a mean recovery value of 97.24 ± 7.36. Intra-day and inter-day precision values were found to be less than 2%. The relative standard deviations (RSDs) of repeatability of sample application and measurement of area were found to be 1.24% and 0.93%, respectively.