Authors:A. Rehman, M. Sajjad, S.H. Khan, R.J. Peña, and N.I. Khan
The allelic variation for Glu-1, Glu-3 loci and presence of IBL-1RS translocation was determined in 126 spring wheat accessions. The most common alleles at Glu-1 loci were Glu-A1b (59.52%), Glu-B1c (41.26%), and Glu-D1d (57.14%) and at Glu-3 loci were Glu-A3c (56.45%), Glu-B3j (29.36%), and Glu-D3b (76.98%). Modern Pakistani wheat varieties carried superior alleles at Glu-1 and Glu-3 loci for bread-making quality and had no negative influence of secalin protein-synthesized by 1BL-1RS translocation. For LMW-GS, the most common combination was Glu-A3c, Glu-B3j and Glu-D3b. The loci Glu-B1 and Glu-B3 had the highest allelic diversity of Glu-1 and Glu-3 loci, respectively.
Authors:A. Khan, H.H. Liu, A. Ahmad, L. Xiang, W. Ali, A. Khan, M. Kamran, S. Ahmad, and J.C. Li
Higher plant population and nitrogen management is an adopted approach for improving crop productivity from limited land resources. Moreover, higher plant density and nitrogen regimes may increase the risk of stalk lodging, which is a consequence of complex interplant competition of individual organs. Here, we aimed to investigate the dynamic change in morphology, chemical compositions and lignin promoting enzymes of the second basal inter-nodes altering lodging risk controlled by planting density and nitrogen levels. A field trial was conducted at the Mengcheng research station (33°9′44″N, 116°32′56″E), Huaibei plain, Anhui province, China. A randomized complete block design was adopted, in which four plant densities, i.e., 180, 240, 300, and 360 × 104 ha−1 and four N levels, i.e., 0, 180, 240, and 300 kg ha−1 were studied. The two popular wheat varieties AnNong0711 and YanNong19 were cultivated. Results revealed that the culm lodging resistance (CLRI) index of the second basal internodes was positively and significantly correlated with light interception, lignin and cellulose content. The lignin and cellulose contents were significantly and positive correlated to light interception. The increased planting density and nitrogen levels declined the lignin and its related enzymes activities. The variety AnNong0711 showed more resistive response to lodging compared to YanNong19. Overall our study found that increased planting densities and nitrogen regimes resulted in poor physical strength and enzymatic activity which enhanced lodging risk in wheat varieties. The current study demonstrated that stem bending strength of the basal internode was significantly positive correlated to grains per spike. The thousand grain weight and grain yield had a positive and significant relationship with stem bending strength of the basal internode. The results suggested that the variety YanNong19 produces higher grain yield (9298 kg ha−1) at density 240 × 104 plants ha−1, and 180 kg ha−1 nitrogen, while AnNong0711 produced higher grain yield (10178.86 kg ha−1) at density 240 × 104 plants ha−1 and with 240 kg ha−1 nitrogen. Moreover, this combination of nitrogen and planting density enhanced the grain yield with better lodging resistance.
Authors:J. A. Guroo, M. Khan, A. Ahmad, A. Azam, and Z. A. Siddiqui
Effect of Graphene oxide (GO) was observed on Meloidogyne incognita and Macrophomina phaseolina and on the growth of lentil in pot experiment. Treatment of plants with 10 ml solution of GO with 125, 250 and 500 ppm concentration caused a significant increase in plant dry weight over control. Inoculation of plants with M. incognita or M. phaseolina caused a significant reduction in plant dry weight over uninoculated control. Treatment of plants with 125, 250 and 500 ppm GO and subsequent inoculation with M. incognita or M. phaseolina caused a significant increase in plant dry weight over plants inoculated without GO pretreatment. Treatment of 500 ppm GO caused a greater increase in plant dry weight of M. incognita or M. phaseolina inoculated plants followed by 250 ppm and 125 ppm. Numbers of nodules per root system were high in plants without pathogen. Inoculation of M. incognita or M. phaseolina caused reduction in nodulation. However, treatment of GO in all the three concentrations had no significant effect on nodulation in plants both with and without pathogens. Treatment of GO resulted in reduced galling, nematode multiplication and root-rot index. Greater reduction in galling, nematode multiplication and root-rot index were observed in plants treated with 500 ppm GO followed by 250 ppm and 125 ppm. Indices were reduced to 4, 3 and 2, respectively, when plants with M. phaseolina were treated with 125, 250 and 500 ppm GO. This study shows that the use of GO is useful for the management of M. incognita and M. phaseolina on lentil.
Authors:M. Najam, M. Anwar-Ul-Islam, A. Ishaq, J. Mirza, A. Khan, and J. Qureshi
Neutron capture gamma-ray activation analysis technique has been used for the non-destructive analysis of Fe, Cr, Ni, Mn and
B in stainless steel and iron ore samples. It has been shown that the use of low energy capture gamma-rays, ranging from 0.2
to 1.4 MeV, helps considerably in reducing the time of analysis. The problem of congestion of peaks due to compton continuum
and the double and single escape peaks in this region of the spectrum has been overcome by using a Ge(Li) detector in conjunction
with a 15.25 cm thick bifurcated NaI(Tl) annulus in anticompton mode. The results obtained by this technique have been compared
with those of the chemical analysis.
Authors:Y.-H. Kim, A.L. Khan, M. Waqas, R. Shahzad, and I.-J. Lee
Silicon (Si) is essential for normal growth and development in plants and is also beneficial for their responses to wounding. However, the mechanisms by which Si acts to mitigate the effects of wounding is not fully understood. This effect possibly occurs through a reduction in the oxidative stresses associated with wounding. Here, we tested this possibility by investigating the effects of applying different concentrations of Si (0,5 and 1,0 mM) to rice plants under wounding stress for a period of 6 and 12 h. We found that a higher uptake of Si was signifiacntly associated with an increase in leaf chlorophyll contet. In response to wounding induced oxidative stress, the extent of lipid bilayer peroxidation was reduced in a dose-dependent manner by Si application for 6 or 12 h. Activity of the catalase enzyme was initially lowered by Si treatment; however, at 1.0 mM Si, catalase activity increased significantly after 12h of wounding stress. A similar response was also observed for a peroxidase enzyme. Polyphenol oxidase showed a significant reduction in activity. We conclude that Si application does not only improve leaf chlorophyll content but can also overcome the oxidative stress due wounds or physical injuries.
Authors:N. W. Ali, S. Abouzid, A. Nasib, S. Khan, J. Qureshi, and M. I. Choudhary
Ashwaghanda, Withania somnifera, is one of the most widely used herbs in Ayurvedic medicine. Leaves and roots are the traditionally used parts of the plant. An RP-HPLC method using a binary acetonitrile-water gradient containing 0.1% acetic acid has been developed for analysis of withaferin A. The method was validated in accordance with ICH guidelines and used for analysis of the withanolide content of the flowers, leaves, and roots of W. somnifera. The withanolide content was highest in the flowers.
Authors:Rabia Nazir, Muhammad Mazhar, Tehmina Wakeel, Muhammad J. Akhtar, Muhammad Siddique, Muhammad Nadeem, Nawazish A. Khan, and Muhammad R. Shah
Pyrolysis of trisbipyridineiron(II) chloride under controlled thermal conditions and inert atmosphere of argon gas yields a residue of iron nanoparticles. Evolved gas analysis by GC–MS and 1H NMR revealed emission of bipyridine, 6-chlorobipyridine, 6,6′-dichlorbipyridine, bipyridine hydrochloride, and hydrochloric acid as decomposition products. CHN, XRPD, EDXRF, TEM, AFM, and 57Fe Mössbauer spectroscopy of the residue indicated formation of pure iron nanoparticles in the size range of 50–72 nm. Based on these results a mechanism for thermal degradation of trisbipyridineiron(II) chloride has been worked out.
Authors:M. W. Abbasi, M. Q. Khan, M. J. Zaki, S. S. Shaukat, A. Rauf, N. Ahmed, M. Azeem, and M. Tariq
Bacillus thuringiensis (B.t) is well known for its biocontrol potential against a variety of insects. Nematicidal potential of ten B.t isolates was tested against root-knot nematodes (Meloidogyne javanica (Treub) Chitwood) in vitro, under greenhouse as well as in field conditions. Eggs and second stage juveniles (J2) were exposed to 5 and 25% concentrations of bacterial cell-free aqueous extracts up to 96 h. B.t isolates showed lesser degrees of nematicidal activity at 5% concentration. However, some B.t isolates (B.t-14, B.t-16 and B.t-64) greatly reduced egg hatching and increased J2. All B.t isolates revealed suppressed egg hatching and increased mortality of J2 at 25% concentration. Soil applications with most of the B.t isolates under greenhouse and field conditions significantly improved height and fresh weights of root-knot nematode parasitized okra (Abelmoschus esculentus (L.) Moench). Some isolates, including B.t-64 reduced the number of galls and egg masses. B.t-64 reduced gall formation up to 70% under greenhouse conditions. However, 29% of decrease was observed in field conditions. Similarly, B.t-64 treated plants showed a 56% decreased in eggs/egg mass in a field experiment. Population of root-knot nematodes in the rhizosphere was decreased up to 61% in the field experiment as compared to control.