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Islolation and Characterization of Plant Based Pesticides

Thesis Info

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External Link

Author

Khan, Saira

Program

PhD

Institute

COMSATS University Islamabad

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Biotechnology

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12660/1/Saira%20Khan_Comsats.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726527235

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Isolation and Characterization of Plant Based Pesticides With the pace of constant population growth, the demand for sufficient and safer food is continuously increasing around the globe. On the other hand, global loss to crops due to pests, diseases and weeds is significantly high, warranting excessive use of pesticides, threatning environmnet and food safety. The most frequently used pesticides are synthetic posing several associated pre and post application problems such as residual toxicity that results in compromising the safety of food and causing insect resistance. An alternative approach may be to utilize plant’s secondary metabolites that plants actually synthesize in their defense against pests and pathogens. The major aim of current research study was, therefore, to identify, isolate, and characterize at biochemical and molecular level the potent insecticidal compounds from plant sources. To achieve this aim, seven plants namely Cinnamomum camphora, Eucalyptus sideroxylon, Isodon rugosus, Boenninghausenia albiflora, Calotropis procera, Daphne mucronata, and Tagetes minuta were selected. The crude and purified extracts of each of these plants were used to screen for their toxic effects against six economically important agricultural pests, each representing a separate insect order; Acyrthosiphon pisum (Hemiptera), Drosophila melanogaster (Diptera), Tribolium castaneum (Coleoptera), Spodoptera exigua (Lepidoptera), Schizaphis graminum (Hemiptera) and Bactrocera zonata (Diptera). Aphids were the most susceptible insects with 100% mortality observed after 24 h for all the plant extracts tested. Further bioassays with lower concentrations of the plant extracts against aphids revealed that the extracts from Isodon rugosus (Lamiaceae) (LC50 36.2 ppm and LC90 102.1 ppm) and Daphne mucronata (Thymelaeaceae) (LC50 126.2 ppm and LC90 197.5 ppm) found out to be the most toxic to aphids, A. pisum. These most toxic and active plant extracts were further fractionated in different solvent fractions on polarity basis and their insecticidal activity was further evaluated. While all fractions showed considerable mortality in aphids, the most active was the butanol fraction from Isodon rugosus with an LC50 of 18 ppm and LC90 of 48.2 ppm. Further bioactivity guided fractionation of the butanol fraction results in isolation of bioactive principle compound that was identified through various spectroscopic techniques as rosmarinic acid with LC50 0.2 ppm and LC90 5.4 ppm. There was no significant difference between LCs of purified rosmarinic acid and of commercial rosmarinic acid. Further, two key genes, hydroxyphenylpyruvate reductase and rosmarinic acid synthase, known to involve in biosynthesis of rosmarinic acid were targeted to clone from Isodon rugosus. Only one of these genes, hydroxyphenylpyruvate reductase was successfully cloned in Isodon rugosus which consequently will open the way to explore all other genes responsible for biosynthesis of rosmarinic acid. The molecular knowledge regarding biosynthetic pathway will help in biotechnological production of rosmarinic acid and to produce aphid resistant plants through genetic engineering approaches. Considering the high mortality rate in aphids to a significantly low concentration of the rosmarinic acid from Isodon rugosus, could be exploited and further developed as a potential eco-friendly plant-based insecticide against sucking insect pests.
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مستری چراغ دین

مستری چراغ دین (۱۹۳۵۔۱۸۵۷) پسرور میں پیدا ہوئے۔ مستری اردو اور فارسی زبان میں شاعری کرتے تھے۔ ۱۹۲۶ء میں آپ مکہ مکرمہ چلے گئے واپس آ کر ’’حج کا ساتھی‘‘ کے نام سے سفر نامہ مرتب کیا۔ خواجہ حسن نظامی نے اس سفر نامہ کو حلقہ مشائخ دہلی کے تحت مارچ ۱۹۲۸ء میں شائع کیا۔ بہت کوشش کے باوجود آپ کا شعری کلام دریافت نہیں ہو سکا۔ ایک شعر ملاحظہ ہو جو انہوں نے اپنے تعمیری مکان کے بیرونی دروازے کی ڈاٹ پر کنندہ کرایا تھا۔

مستری کو فکر تھا تاریخ کا                              کہ دیا ہاتف نے قصر دل پذیر      (۳۱)

۳۱۔         ڈاکٹر سلطان محمود حسین،’’تاریخِ پسرور‘‘لاہور‘ سنگ میل پبلی کیشنز‘ ۱۹۸۱ء ‘ ص : ۲۷۱

 

غنة الزواج وانتظارھا في الفقه الاسلامي

It is a matter of proven fact that Islamic shairat is a complete code of life. It is comprehensive and it covers all aspects of human life which include prayers, human rights, marriage, dealings, and justice, etc. Relation between two individuals of opposite gender [known as Nikah (the marriage) ] has also been given great importance and related issues have been discussed in detail, so that man and women, when related with each other, may live their lives happily and peacefully and to remain aloof from sins. In this article it has been comprehensively discussed if after marriage a man is not capable of having sexual relations i. E., Jamah or impotency. What should a woman do? In this respect, Islamic scholars presented different opinion; some consider that Nikah (marriage) would not be void, while others consider that the husband should be given one year time for medical treatment, and if after one year he did not gain the capability, then “Nikah” would be annulled. The word ‘impotence’ has different meanings, including: object to thing, and does not want women. According to Scholars’ terminology: impotence is the inability to penetrate in sexual intercourse. The sexually impotent adult husband identifies him an appointment for a year, if he does not have intercourse, then his impotency will be proved, and his wife may annul the marriage contract. If the sexually impotent is still young, he will not have an appointment. The mad sexually impotent wife postpone as the adult sexually impotent. Castrate wife postpone reserves and retention of marriage contract.

Design of Adaptive Algorithms for Estimation in Single-Agent and Multi-Agent Environments

Contribution of adaptive filters in the evolution of modern communications is remarkable. The logic of adaptive filtering establishes a significant part in the tool-set of statistical signal processing. For the problem of adaptive estimation, computational cost, convergence rate, steady-state error, stability and generalization are considered to be the main challenges. In this work several novel adaptive algorithms are developed to address these challenges. This work focus on two different types of environments, namely single-agent environments and multi-agent environments. In singleagent environments, data arrives at a single node for the estimation of a parameter of interest. For such environments we propose a novel idea of q-calculus based adaptive analysis. The qgradient is an extension of the classical gradient vector based on the concept of Jackson’s derivative. The q-derivative takes larger steps in the search direction as it evaluates the secant of the cost function rather than the tangent (as in the case of a conventional derivative). Motivated by this, in this work we developed several algorithms/ideas in which we addressed the short comings of the standard least mean square (LMS) and its variants by using q-calculus, such as, the q-least mean square (q-LMS) algorithm, in which we minimize the LMS cost function by employing the concept of q-derivative instead of the conventional derivative, the q-normalized least mean square (qNLMS), the two-dimensional q-least mean square (2D-qLMS) algorithm and the q-LMS for tracking a non-stationary channel. Consequently, several new explicit closed-form expressions for the meansquare-error (MSE) behavior are derived for the transient and steady-state analysis. On the other hand multi-agent signal processing has attract a number of researchers owing to better statistical inference in wireless networks and is therefore effectively utilized in many applications such as wireless sensor networks, smart grids etc. In multi-agent environments, data arrives at multiple nodes that are distributed over a geographical area and have a common task of estimation of a desired parameter. There are two major estimation techniques used for distributed environments: (1) centralized estimation, and (2) decentralized estimation. In centralized estimation, all the estimations take place at a single processor by sharing data from each node at a centralized unit. Such an estimation requires powerful processor along with massive amount of communication and power. To overcome these problems a decentralized estimation solution is proposed in literature, in which each node has its local estimate which is shared with the neighbors in an explicit manner (such as incremental, diffusion etc). Decentralized estimation techniques suffer from: (1) link failure problem, (2) instability issues, and (3) computational cost (particularly in the context of state-space estimation models). To deal with these problems, a number of innovative methodologies are proposed. Firstly a convex combination-based incremental least mean square (LMS) algorithm is proposed to overcome the problems of link failure between the nodes and instability in case local divergence in incremental mode of cooperation. The proposed algorithm is developed by employing convex combination of two filters. The adaptation of one filter is based on the estimate of adjacent node (incremental type), while the adaptation of the other is based on the estimate of the current local node at the previous time instant. These two filters are then fused together by using a suitable mixing parameter. Secondly to minimize the steady-state error, an optimum error non-linearity based incremental mode of cooperation is proposed. Thirdly, to reduce the computational cost for state-space estimation in distributed environments, a state-space least mean square algorithm for diffusion mode of cooperation is proposed. The proposed algorithm minimizes the computational complexity at each node which intern provides a significant advantage in terms of computational cost of the overall network and hence, can improve the response time of the network. Both the convergence in the mean and the mean square analysis of the proposed algorithm are performed and the transient and steady-state behavior of the proposed algorithm is analyzed.