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831.
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Shahid Faiza Aman Afsheen Nawaz Muhammad Asif Karim Asad Ul Qader Shah Ali 《Bioprocess and biosystems engineering》2017,40(3):451-461
Bioprocess and Biosystems Engineering - Dextranase is a unique biocatalyst that has high specificity and stereo-selectivity towards a complex biopolymer known as dextran. Dextranase has wide... 相似文献
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836.
Anouch Missirian Eyal G. Frank Jess T. Gersony Jason C. Y. Wong Shahid Naeem 《Ecology and evolution》2019,9(12):6949-6958
The influence of temperature on diversity and ecosystem functioning is well studied; the converse however, that is, how biodiversity influences temperature, much less so. We manipulated freshwater algal species diversity in microbial microcosms to uncover how diversity influenced primary production, which is well documented in biodiversity research. We then also explored how visible‐spectrum absorbance and the local thermal environment responded to biodiversity change. Variations in the local thermal environment, that is, in the temperature of the immediate surroundings of a community, are known to matter not only for the rate of ecosystem processes, but also for persistence of species assemblages and the very relationship between biodiversity and ecosystem functioning. In our microcosm experiment, we found a significant positive association between algal species richness and primary production, a negative association between primary production and visible‐spectrum absorbance, and a positive association between visible‐spectrum absorbance and the response of the local thermal environment (i.e., change in thermal infrared emittance over a unit time). These findings support an indirect effect of algal diversity on the local thermal environment pointing to a hitherto unrecognized biodiversity effect in which diversity has a predictable influence on local thermal environments. 相似文献
837.
Argemone mexicana L. (Papaveraceae), a tropical annual weed, is phytotoxic to many crop species. This study was designed to examine the allelochemical and nematicidal potential of A. mexicana and to better understand the role of this weed in the ecosystem. A methanol-soluble extract of the leaf material caused greater juvenile mortality of Meloidogyne javanica than did ethyl acetate or hexane extracts indicating the polar nature of the toxins. Decomposing tissues of A. mexicana in soil at 50 g kg–1 were highly deleterious causing 80% mortality of tomato plants. At 10 g kg–1 plant growth was enhanced, while at 30 g kg–1 plant growth was substantially retarded. M. javanica population densities in the rhizosphere and in roots, and gall formation were significantly suppressed when 10, 30 or 50 g kg–1
A. mexicana was allowed to decompose in the soil. To establish whether decomposition was necessary to produce phytotoxic symptoms, or whether the shoot extract alone could interfere with plant growth, an aqueous shoot extract was applied to soil. Whereas a 50% extract promoted plant growth, a 100% (100 g/500 mL distilled water) concentration significantly reduced plant height, and fresh weights of shoot and root. In general, decomposing plant material caused greater phytotoxicity compared to the aqueous extract. Addition of N as NH4NO3 partially alleviated the phytotoxic action of A. mexicana,and also reduced severity of root-knot disease. Adding Pseudomonas aeruginosa to soil amended with A. mexicana resulted in decreased density of M. javanicain the rhizosphere and in tomato roots, suppressed galling rates and enhanced plant growth. 相似文献
838.
Esraa E. Shalan Said S. Soliman Ahmed A. Mahmoud Jameel M. Al-Khayri Salha M. ALshamrani Fatmah A. Safhi Areej S. Jalal Diaa Abd El-Moneim Abdallah A. Hassanin 《Phyton》2023,92(7):2183-2196
Determination of the somaclonal variation of in vitro-propagated plants is crucial to determine the appropriate
micropropagation protocol and growth regulators for commercial scale multiplication. In this research, nine multiplication media (MM) augmented with different concentrations of 6-benzyl adenine (BA), Kinetin (Kin), and
Thidiazuron (TDZ), Three rooting media (RM) supplemented with three levels of α-naphthalene acetic acid
(NAA) and three types of soil mixtures (v/v); Coco peat/Vermiculite/Sand (CVS), Peat moss/Perlite/Sand
(PPS) and Peat moss/Perlite (PP) were used in the micropropagation protocol of daylily plants. MM2 showed
the maximum shoot length and the number of leaves, while MM9 showed the maximum number of shoots.
The RM1 showed the maximum root length and the number of roots. During acclimatization, CVS, PPS, and
PP soil mixture showed similar performance except the CVS mixture showed lower performance regarding plant
height and diameter. The genetic fidelity of micropropagated plants was evaluated using Start Codon Targeted
(SCoT) Markers. Six SCoT primers amplified 51 scorable bands with an approximate range from 146 bp to
1598 bp size. Thirty one out of 51 loci were presented in the mother plants. 40 loci were polymorphic, 11 were
monomorphic and 7 were unique. The amplification patterns of the micropropagated plants demonstrated genetic integrity to the mother plant ranging from 84.32 to 47.06 and somaclonal variations ranging from 52.94 with
5 mg/l BA pathway to 15.68 with 1mg/l TDZ pathway, thus demonstrating that the homogeneity and the variation of the micropropagated plants affected by the type and the quantity of the plant growth regulator used during
multiplication subcultures. This research can be successfully used for other ornamental and medicinal plants’ bulk
multiplication, germplasm conservation, and future genetic improvement. 相似文献
839.
Jameel M. Al-Khayri Christine E. Shamblin Edwin J. Anderson 《In vitro cellular & developmental biology. Plant》1996,32(4):227-232
Summary This study was conducted to establish and optimize a regeneration system for adapted U.S. rice genotypes including three commercial
rice cultivars (LaGrue, Katy, and Alan) and two Arkansas breeding lines. Factors evaluated in the study were genotype, sugar
type, and phytohormone concentration. The system consisted of two phases, callus induction and plant regeneration. In the
callus induction phase, mature caryopses were cultured on MS medium containing either 1% sucrose combined with 3% sorbitol
or 4% sucrose alone, and 0.5 to 4 mg·L−1 (2.26 to 18.10 μM) 2,4-D with or without 0.5mg·L−1) (2.32 μM) kinetin. In the plant regeneration phase, callus was transferred to 2,4-D-free MS medium containing 0 or 2 mg·L−1 (9.29 μM) kinetin combined with 0 or 0.1 mg·L−1 (0.54 μM) NAA. Callus induction commenced within a week, independent of the treatments. Callus growth and plant regeneration, however,
were significantly influenced by interactions among experimental factors. Generally, the greatest callus growth and plant
regeneration were obtained with 0.5 mg·L−1 (2.26 μM) 2,4-D and decreased with increasing 2,4-D concentrations. Kinetin enhanced callus growth only when combined with 0.5 mg·L−1 (2.26 μM) 2,4-D, and 4% sucrose. Inducing callus on kinetin-containing medium generally enhanced regeneration capacity in the presence
of sucrose but not with a sucrose/sorbitol combination. Media containing sucrose alone generally supported more callus proliferation,
but the sucrose/sorbitol combination improved regeneration of some cultivars. NAA and kinetin had little effect on regeneration. 相似文献
840.
Maryam Akram Maria Saleem Khan Sammia Shahid Hafiz Muhammad Abdur Rahman Iram Nadeem 《Bioscience, biotechnology, and biochemistry》2020,84(10):1967-1974
ABSTRACT This work presents the development and validation of a simple, rapid, and cost-effective spectrophotometric method for quantitative analysis of uric acid in biological samples. The method relies upon uric acid-led reduction of Fe(III) to Fe(II) of sample/standard solutions which stoichiometrically engages ferrozine to form a magenta-colored complex. Different parameters including pH, metal and chelator concentrations, temperature, etc., were optimized for the maximum intensity and stability of the complex. The uric acid concentrations of synthetic/plasma solutions were determined by comparing the color intensity of Fe(ferrozine)3 2+ complex produced by test solution with the standard curve formed by known uric acid concentrations. The method was validated in accordance with ICH guidelines and subjected to human plasma analysis. The results obtained were compared with a reference (enzymatic) method which revealed that there was no significant difference between the two methods at 95% confidence level. The method is highly specific, precise, linear, accurate, and robust. 相似文献