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  • Author or Editor: A. Hameed x
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High molecular weight (HMW-GS) and low molecular weight (LMW-GS) glutenin subunits play a significant role in bread making quality and extensibility, though they signify merely 10% and 40% of the entire seed storage proteins. For the estimation of bread quality on the basis of allelic difference in HMW-GS and LMW-GS at Glu-1 and 3 loci, wheat germplasm (77 genotypes) was collected from diverse agro-climatic regions of Pakistan and characterized by using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Thirty distinct allelic arrangements were identified with a sum of thirteen Glu-1 alleles. Maximum frequency of allele 1 was found in twenty-nine genotypes at Glu-A1 locus while high proportion of subunit pairs 13 + 16 and 2 + 12 was detected in 33 and 32 genotypes at Glu-B1 as well as Glu-D1 locus, respectively. Few rare alleles were also separated out. The quality scores ranged from 4–10, however highest quality score of ten was more recurrent (36.36%). A good quality score of 8 and 6 were found in 32.47% as well as 19.48% of genotypes individually. In LMW-GS, seventeen diverse combinations of alleles with aggregate of ten Glu-3 alleles were detected. Glu-A3c and Glu-B3d alleles were observed in 33 (42.85%) genotypes, encoding high sedimentation and protein contents. Hence, this will enable the breeders to utilize both glutenin subunits as biochemical indicator for selecting superior wheat genotypes possessing enhanced bread making quality.

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Grain Protein Content (GPC) of wheat is significant for enhanced nutritional value and is one of the most important aspects effecting pasta and bread making quality as well. Seventy seven Pakistani wheat varieties and advance lines were analysed to access the allelic distribution at microsatellite Xuhw89 locus using functional SSR marker. Overall, 42% of tested wheat genotypes were found to carry 126 + 130-bp allele while a 126-bp allele was detected in 58% of genotypes. A target band of 126-bp was amplified in all tested genotypes, however, an additional band of 130-bp was also detected along with 126-bp band in 32 genotypes. Genotypes i.e. (Punjab-96) total soluble protein and (MEXI PAK) globulin with 126 + 130-bp allele while (Faisalabad-2008) salt soluble protein and (TC-4928) albumin with allele of 126-bp depicted highest grain protein content. The alleles identification associated with maximum grain protein content in Pakistani wheat germplasm will assist in accelerating the breeding program in future.

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Drought is a worldwide problem, getting more serious with global climate change. Among various strategies, seed priming is the simplest approach for improving drought tolerance in crop plants. Seed priming treatments were applied by soaking seeds in aerated solution of 1% mannose (56 mM) and 10 mM mannitol for 8 h while 100 μM H2O2 for 5 h. Seeds soaked in aerated water (hydropriming) and non-primed seed were used as controls. Drought stress significantly reduced the seedling fresh weight and leaf relative water content. Pre-sowing seed treatment with mannitol significantly increased the seedling, root and shoot fresh as well as dry weights under non-stress condition. Moreover, H2O2 increased the root length; seedling and root dry weights while mannose increased the shoot dry weight under drought stress. Leaf relative water content (RWC) improved after mannitol and H2O2 priming under drought and non-stressed conditions. Hydropriming increased the root and shoot fresh weights, shoot dry weight and RWC under non-stress condition while seedling, root, shoot fresh weights and shoot dry weight along with raised TSP, MDA, reducing sugars under drought stress. Drought stress raised the total soluble protein (TSP), protease, APX and POD activities, MDA and reducing sugars in leaves. Mannitol and H2O2 confiscate the drought-induced increase in TSP while H2O2 significantly increase it under non-stress condition. Drought stress reduced the catalase activity in leaves while H2O2 and mannitol priming brought it back to control level. Drought stress elevated the MDA in leaves and H2O2 treatment prevented this increase. Only mannose priming rose the reducing sugars in leaves under non-stress condition. Under drought, mannose and mannitol priming raised the reducing sugars in the leaves as a tactic for osmotic adjustment. In conclusion, seed priming treatments ameliorated the drought tolerance in wheat by elevating the level of antioxidants, reducing oxidative damage of biomolecules and accumulating more reducing sugars for osmotic adjustments.

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Lipases are a class of enzymes which catalyze the hydrolysis of long-chain triglycerides. Microbial lipases are currently receiving much attention with the rapid development of enzyme technology. Bacillus subtilis FH5, isolated from tannery wastes, produced a thermostable alkalophilic lipase and was purified to homogeneity as judged by SDS-PAGE. The purification steps included acetone fractionation and sequential column chromatography on DEAE-cellulose, Sephadex G-75 and adsorption chromatography on Hydroxylapatite. The results of chromatographies showed that two types of lipases were present having molecular weights approximately 62 kDa and 24 kDa, respectively. The purified enzyme was found to be 100% stable at pH 10 and about 80% residual activity was present at 60°C. The enzyme was found to be stable in the presence of Mg 2+ , Mn 2+ and Ca 2+ ions. K m value was calculated as 5.05 mM and V max as 0.416 μmol/ml/min. Bacillus subtilis FH5 was isolated from tannery waste, therefore, enzyme is environmentally compatible for application in leather degreasing process.

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Detection of genotypic variation in response to water stress at seedling stage could help in escalating selection intensity in breeding drought tolerant varities. Nine genotypes were tested for seedling survivability under drought stress. Four genotypes, i.e. ‘Sarsabz’, ‘Sitta’, ‘Fareed’ and ‘FD-83’, showed complete survival on resumption of irrigation after drought stress. These genotypes were late dying as they withered slowly under drought. Percent wilting and percent survival on resumption of irrigation were negatively correlated. Six genotypes were selected on the basis of seedling survivability (late and early dying) and evaluated for seedling growth response under drought. Root length and dry weight increased significantly under stress in ‘Sitta’, ‘FD-83’ and ‘Fareed’. Drought stress also increased the root-to-shoot length ratio in ‘FD-83’ and ‘Fareed’. However, seedling fresh and dry weight significantly reduced in ‘Nesser’ and ‘Inqalab-91’ under stress. In ‘FD-83’, seedling fresh and dry weight increased over control under stress. Results indicated that seedling survivability, root-to-shoot length ratio, root length and dry weight were most important traits for screening drought tolerance at seedling stage. On the basis of these indices, ‘Sitta’, ‘Fareed’ and ‘FD-83’ were classified as drought tolerant, ‘Sarsabz’ and ‘Nesser’ as moderately tolerant and ‘Inqalab-91’ as sensitive genotypes. Collectively, results suggested that selection by combining seedling survivability, growth response, RWC and leaf water potential can be efficiently used for rapid evaluation of drought tolerance in wheat breeding.

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A new bacterial strain, capable of degrading poly(3-hydroxybutyrate) (PHB) was isolated from soil. This organism, identified as Streptoverticillium kashmirense AF1, secreted PHB depolymerases both on solid as well as in liquid mineral salt medium containing poly(3-hydroxybutyrate) as sole carbon source. The optimum production of PHB depolymerase was observed at pH 8 and 7, at 45 °C, 1% substrate concentration and in the presence of lactose as an additional carbon source. The extracellular PHB depolymerase was purified by gel permeation chromatography using Sephadex G-75. The Streptoverticillium kashmirense AF1 produced two types of PHB depolymerases having molecular weights of about 37 and 45 kDa as determined by SDS-PAGE. The difference in dry cell mass and amount of CO 2 evolved in the test and control calculated gravimetrically through Sturm test indicated the degradative capabilities of Streptoverticillium kashmirense AF1.

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Genetic diversity of 48 Pakistani wheat varieties and 12 landraces was assessed, loss of genetic diversity in bread wheat during the change from traditional landraces (LVs) to modern breeding varieties was examined, and recent trends of national wheat breeding programmes were identified. A total of 29 SSR markers, representing at least one marker from each chromosome of wheat, were used to analyze the genetic diversity. A total of 80 alleles were generated by the 29 loci with an average of 2.76 alleles per marker. A significant loss of genetic diversity was observed from LVs to elite cultivated varieties. Average genetic similarity between landraces was 61% while varieties released after 1990 showed 73% similarity. Range of genetic distance observed between all possible pairs was from 1.41 to 4.90. It was also observed that most of the varieties released from one source showed comparatively lower diversity indicating the utilization of common elite breeding material or interbreeding of released varieties.

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Summary

Two methods were presented for the simultaneous determination of two multicomponent mixtures containing pyridoxine hydrochloride (B6) and cyanocobalamine (B12) with benfotiamine (BN) [mix. 1], or thiamine nitrate (B1) and diclofenac sodium (DC) [mix. 2]. The first high-performance liquid chromatographic (HPLC) method depends on the use of a cyanopropyl column at a flow rate of 1.5 mL min−1 with a mobile phase consisting of acetonitrile-25 mM ammonium acetate, pH 3.7 (10:90, v/v), for mix. 1 or acetonitrile-25 mM ammonium acetate, pH 5.0 by gradient elution, changing the proportion of the system linearly with a time schedule program, for mix. 2. Quantitation was achieved by UV detection at 220 nm. The second method was based on HPTLC separation followed by densitometric measurement of the spots at 254 nm. The separation was achieved on HPTLC silica gel F254 plates using chloroform-ethanol-water-acetic acid (5:8:2:0.5, v/v/v/v) for mix. 1 and chloroform-ethanol-water-acetic acid (1.5:8:2:0.5, v/v/v/v) for mix. 2. The proposed methods were successfully applied for the analysis of pharmaceutical formulations containing the two multicomponent combinations.

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Abstract

Evaluation studies were carried out to simulate realistic field exposures of sulfoxaflor and flonicamid against Aphis gossypii at foraging time of Apis mellifera. Semi-field trials of field rates of sulfoxaflor and flonicamid against A. gossypii laboratory strain at 48 h of exposure had equipollent overall mean of mortality of 62.50 and 63.50%, respectively in season of 2020, likewise 60.50 and 62.50%, respectively in season of 2021. Lethal time values (LT1) had ranges of 51.33–32.46 days for sulfoxaflor and 49.00–39.55 days for flonicamid. Laboratory trials on foraging honeybees (∼21 days old) at 5 h of exposure showed an excellence for sulfoxaflor (5.00%) in overall mean of mortality compared to flonicamid (2.75%) in season of 2020. Likewise, sulfoxaflor (4.75%) surpassed flonicamid (2.75%) in season of 2021. The highest LT1s on honeybees for sulfoxaflor and flonicamid reached 27.45 and 10.94 days, respectively. International Organization for Biological Control classified both insecticides to be harmless on honeybees. Survival foraging bees exposed to LD50s of the tested insecticides had malformed digestive tracts gradually vanished along week of exposure. Suggestions for foliar spray stoppages prior to flowering period were mentioned for both insecticides.

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