4,273 research outputs found

    Genetic analysis for various yield components and gluten content in bread wheat (Triticum aestivum L.)

    Get PDF
    Genetic analysis was carried out in 55 genotypes (10 parents and 45 F1s) through diallel mating design excluding reciprocals in bread wheat (Triticum aestivum L.). Analysis of variance showed wide range of variability among the breeding material for all the traits under study. The highest value of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were recorded for grain yield (PCV= 9.07 and GCV= 8.08). Highest heritability with genetic advance was recorded for grain yield (h2=10.60 and GA=14.84), therefore selection will be effective based on grain yield for further study. Grains per spike (gr = 0.77 and pr = 0.67) and spikelets per spike (gr= 0.63 and pr = 0.52) were found significantly correlated (at <1 % level of significance) with grain yield whereas gluten content showed nonsignificant but positive correlation with grain yield at both genotypic as well as phenotypic level. Similarly, path coefficient analysis estimates for gluten content (g= 0.08 and p= 0.03) and grains per spike (g=0.36 and p=0.23) showed high positive direct effects on grain yield therefore these traits may be used as an index for selection to high yield in bread wheat genotypes

    Thermomechanical properties of a single hexagonal boron nitride sheet

    Get PDF
    Using atomistic simulations we investigate the thermodynamical properties of a single atomic layer of hexagonal boron nitride (h-BN). The thermal induced ripples, heat capacity, and thermal lattice expansion of large scale h-BN sheets are determined and compared to those found for graphene (GE) for temperatures up to 1000 K. By analyzing the mean square height fluctuations <h2>< h^2> and the height-height correlation function H(q)H(q) we found that the h-BN sheet is a less stiff material as compared to graphene. The bending rigidity of h-BN: i) is about 16% smaller than the one of GE at room temperature (300 K), and ii) increases with temperature as in GE. The difference in stiffness between h-BN and GE results in unequal responses to external uniaxial and shear stress and different buckling transitions. In contrast to a GE sheet, the buckling transition of a h-BN sheet depends strongly on the direction of the applied compression. The molar heat capacity, thermal expansion coefficient and the Gruneisen parameter are estimated to be 25.2 J\,mol−1^{-1}\,K−1^{-1}, 7.2×10−6\times10^{-6}K−1^{-1} and 0.89, respectively

    Estimates of genetic components and regression analysis for grain yield and various morphological traits in bread wheat (Triticum aestivum L.)

    Get PDF
    The present study was conducted to estimate the gentic components and regression analysis for grain yield and various morphological traits in bread wheat involving 10 parents and their 45 F1s (half diallel) during 2012- 13 and 2013-14. Significant additive (D) and dominance (H1) variance for the traits indicated that expression of these traits is control by both additive and dominance gene action. Average degree of dominance (H1/D)1/2 were more than unity for the traits (peduncle length, flag leaf area, productive tillers, biological yield, grain yield, harvest index) indicating the preponderance of over dominance gene action. The estimates of h2 were positive and significant for days to ear emergence, peduncle length, productive tillers, biological yield and grain yield indicated dominance of genetic components in F1s. Positive and significant values of F were estimated for days to ear emergence, days to 50% flowering, spike length, flag leaf area and grain yield in F1s indicating the preponderance of dominance and positive genes in the parents involved. The theoretical value (0.25) of (H2/4H1) for all the traits indicated asymmetrical distribution of positive and negative genes. The proportion of dominant and recessive alleles indicated presence of dominant alleles in the parents. The traits showing more than 30% narrow sanse heritability could be rewarding for further improvement in grain yield in bread wheat. Regression analysis indicated that the traits (days to ear emergence, days to 50% flowering, peduncle length, flag leaf area, productive tillers, harvest index, biological yield and grain yield) control by over dominance type of gene action. The parent RAJ 4246 contained maximum dominant genes for days to ear emergence and days to 50% flowering; HD 2733 for spike length and flag leaf area and HD 2824 for productive tillers, biological yield and grain yield used as donors in multiple traits breeding programme to develop high yielding wheat genotypes

    Identification of heterotic cross combinations for various agromorphological and some quality traits in bread wheat (Triticum aestivum L.)

    Get PDF
    A study was conducted to identify the best heterotic cross for various agromorphological and some quality traits involving 10 parents and their 45 F1s excluding reciprocals during 2012-13 and 2013-14. The higher magnitude of heterosis for all the agromorphological and quality traits was not expressed in a single cross combination. It varied from cross to cross due to diverse genetic background of their parents. The highest heterobeltiosis (35.68%, 11.11%, 11.44%), average heterosis (38.97%, 9.13%, 10.26%) and standard heterosis (31.09%, 7.84%, 10.41%) for grain yield, spikelets per spike and grains per spike respectively, was showed by HD 3095 x RAJ 4246 and this cross also showed highly significant (at &lt;1% level of significant) heterosis for biological yield, flag leaf area, spike length and productive tillers. Whereas PBW 435 x RAJ 4246 were common for gluten content (8.52% and 7.72%), grain yield (33.11% and 33.64%), productive tillers (16.15% and 13.53%) and biological yield (36.27% and 21.98%) which showed superior average heterosis and heterobeltiosis respectively, therefore, these crosses may be exploit-ed in a national hybrid wheat breeding programme may offer genetic improvement in breeding for higher grain yield, agromorphological and quality traits in bread wheat. The presence of high heterosis for yield contributing compo-nents is not only for developing hybrids through exploitation of heterosis but also helps to produce transgressive segregants for developing of superior homozygous lines

    Patelloplasty with and without circumpatellar denervation in reducing anterior knee pain in primary total knee arthroplasty: a comparative prospective study

    Get PDF
    Background: Anterior knee pain (AKP) following total knee arthroplasty (TKA) ­­­­­­is one of the complication which cause dissatisfaction in patients. Incidence estimated to be 4-49%. The aim of our study is to know the efficacy of patelloplasty with circumpatellar denervation with diathermy in reducing AKP in primary TKA.Methods: A total of 130 unilateral TKAs’ are divided into 2 groups. Group I (control) includes 65 patients in which only patelloplasty was done. Group II (intervention) includes 65 patients in which both patelloplasty and circumpatellar denervation with diathermy was done and analysed. Mean follow up period was 18 months. Patients were assessed both preoperatively and postoperatively at final follow up.Results: The overall incidence of AKP at follow up (18 months) was 16.9%, with 7.7% in the intervention group and 26.1% in the control group (p&lt;0.05).  Western Ontario and McMaster Universities osteoarthritis index scores were significantly  better in intervention group when compared to control group (28.71±3.948 vs 31.40±3.860). Better results were also found in knee society scores for intervention group compared to control group (166.57±7.941 vs 161.23±11.219); Feller patellar score of  intervention group was significantly better when compared to control group (23.28±2.546 vs 20.69±3.729); the range of knee flexion was similar in both the groups (94.62±12.6 vs 93.54±10.7). In terms of pain referred by the patient at 72 hrs postoperatively, there was statistically significant difference observed according to visual analogue scale.Conclusions: There is statistically significant difference with respect to AKP in patients who have undergone patelloplasty with circumpatellar denervation using diathermy compared with patelloplasty alone.

    IMPROVED CLASS OF ESTIMATORS USING MULTI-AUXILIARY INFORMATION IN SUCCESSIVE SAMPLING

    Full text link
    <p>The present study propounded an improved class of estimators using multi-auxiliary information in successive sampling at both the design and the estimation stages. The proposed method is an extension of the work by Tankou and Dharmadhikari (1989) in successive sampling. The present study is compared with the work carried out by Olkin (1958). The numerical illustration is carried out to show the performance of the proposed strategy.</p

    X-ray studies on the columnar structures of discotic liquid crystals

    Get PDF
    Since the discovery of discotic liquid crystals in 1977 [1] the field has grown rapidly with an estimated 3000 compounds belonging to this category. Generally these compounds have flat or nearly flat cores and surrounded by four to eight long chain substituents. A vast majority of these compounds exhibit the columnar mesophase. This phase is characterized by a structure in which thedisc shaped molecules are stacked one on top of the other to form columns, the different columns constituting a two-dimensional lattice. Several variants of the columnar structure have been identified-upright columns, tilted columns, hexagonal lattice, rectangular lattice, etc. The stacking of the discs within the column could be on the one extreme, liquid-like or on the other have a true long range order. Although X-ray measurements on quite a few compounds exhibiting these different structures have been reported, the temperature dependence of the various structural parameters does not seem to have received much attention. We have used an image plate detector to carry out detailed X-ray studies of several compounds exhibiting the columnar phase. Analysis of the X-ray patterns yields, apart from information on the structural symmetry in terms of the planar space groups, quantitative data on (i) the ordering of the chains and the cores of the mesogens, (ii) the core-core correlation length along the column axis and (iii) the intercolumnar spacing. In particular, it is seen that the extent of ordering of the discs within the columns has significant temperature dependence. Data collected as a function of temperature will be presented and questions regarding ordering within the columns addressed, particularly in two compounds, one of which exhibits a columnar to a plastic phase transition and the other, a columnar to a helical phase transition
    • …
    corecore