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Home > Use of Genetic Variability and Mineral Nutrition to Minimize Cadmium Accumulation in Wheat

Use of Genetic Variability and Mineral Nutrition to Minimize Cadmium Accumulation in Wheat

Thesis Info

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Author

Naeem, Asif

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2336/1/2815S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727646539

Similar


Cadmium is toxic heavy metal soil pollutant and contamination of plant-based foods accounts for at least 70 % of Cd intake by humans. Cultivating low-Cd plant species and optimum application of zinc (Zn) and silicon (Si) nutrients was hypothesized as a possible solution to avoid Cd intake. The research project is comprised of six separate experiments focusing on four major issues: i) identification of variation in Cd accumulation and tolerance among wheat cultivars under cultivation in Pakistan; ii) evaluating root zone acidification and antioxidants response of low and high Cd accumulating wheat cultivars to Cd stress; iii) underpinning the mechanism by which silicon could lower Cd in plants and optimizing its rate of application; and iv) determining the effect of combined Zn and Si application on Cd concentration in wheat grains. Considerable variation in shoot and root Cd concentration was observed among the wheat cultivars that was found to be regulated by differences in both absorption by roots and translocation to shoots. Decrease in root zone pH was not related to shoot Cd concentration of the cultivars and Cd concentration in low-shoot- Cd cultivars was related to sustained or higher activity of antioxidant enzymes which was not observed for high-shoot-Cd cultivars. Higher retention of Cd in roots of both low and high Cd accumulating cultivars while decrease in excessive transpiration only in HSCd cultivars with Si application proved to be the mechanisms suppressing Cd translocation to shoots. Higher increase in antioxidant activity with corresponding higher decrease in shoot Cd concentration in low-shoot-Cd cultivars suggested that improvement in antioxidant activity was associated with lowering Cd concentration in tissue. In soil, Si decreased Cd concentration in wheat cultivars by both decrease in plant available soil Cd and its translocation from roots to shoots. Moreover, application of Si at 150 mg kg-1 proved to be the optimum level of Si that significantly lowered Cd concentration in wheat grains. The combined application of Zn and Si decreased Cd concentration in soil and consequently in grains and straw of wheat cultivars without affecting Zn concentration in grain and straw. Zinc decreased grain Cd concentration by lowering its translocation from shoot to grain and was depending on Zn uptake and translocation efficiency of wheat cultivars. Silicon induced improvement in grain yield and decline in Cd concentration was higher for salt-affected than normal soil and also for salt- sensitive compared to -tolerant wheat cultivars.
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بچپن مولانا احمد رضا بریلوی

بچپن مولانااحمد رضابریلوی
نحمدہ ونصلی علی رسولہ الکریم امّا بعد فاعوذ بااللہ من الشیطن الرجیم
بسم اللہ الرحمن الرحیم
معزز اسا تذہ کرام اور میرے ہم مکتب ساتھیو!
آج مجھے جس موضوع پر اظہار خیال کرنا ہے وہ ہے:’’بچپن مولانا احمدرضابریلوی ‘‘
صدرِذی وقار!
انسان کے تین ادوار ہوتے ہیں جو اس کی شخصیت کی ہمہ گیریت پر روشنی ڈالتے ہیں، اس کے شخصی حسن کے نکھار کا پتہ دیتے ہیں، اس کی زندگی کے نشیب و فراز کے بارے میں آگاہی بہم پہنچاتے ہیں ، اس کی معاشی، معاشرتی، سیاسی اور مذہبی حیثیت کی نشاندہی کرتے ہیں۔
جنابِ صدر!
ضروری تو نہیں کہ یہ تینوں ادوار ایک پہ آئیں۔ کسی نے بچپن میں داعی اجل کو لبیک کہنا ہوتا ہے، کسی نے جوانی میں زندگی کی بوقلمو نیوں کو خیر باد کہنا ہوتا ہے، اور کوئی ایسے ہوتے ہیں جن کو زندگی پیرانہ سالی تک مہلت دیتی ہے اور تادیر زندہ رہتے ہیں۔
صدرِذی وقار!
وہ خوش نصیب ہوتا ہے جس کے بچپن میں ، جس کی جوانی میں، جس کے بڑھاپے میں ہم آہنگی ہوتی ہے۔ جس کے یہ ایّام معاشرے کے لئے ،قوم کے لئے ،خاندان کے لئے مفید اور سودمند ہوتے ہیں، جو بچپن سے لے کر پیرا نہ سالی تک ہر شعبہ ٔحیات میں ایک نمونہ ثابت ہوتا ہے۔
جنابِ صدر!
کئی نابغۂ روزگار ہستیاں ایسی گزری ہیں جن کی زندگی پیدائش سے لے کر قبرکی لحد تک مثالی رہی ہیں۔ لیکن ان نفوسِ قدسیہ میں اعلیٰ حضرت عظیم البرکت امام احمد رضا خان بریلوی رحمۃ اللہ علیہ نے جو مقام حاصل کیا ہے وہ مہر نیم روز کی طرح متبیّن اور واضح ہے۔
معزز سامعین!
اللہ نے آپ کو دینِ اسلام کا خادم پیدا فرمایا، عشقِ مصطفیٰؐ آپ کی رگوں میں خون کی طرح...

ISOMERISM: IS THERE MISCONCEPTION?

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An Exploration of Teachers Knowledge, Beliefs and Practices in Integrating Ict in Different Curriculum Areas in a Secondary School in Pakistan

Teachers' knowledge, beliefs and practices play a significant role in influencing how and why teachers teach. Thus, exploring teachers' knowledge, beliefs and practice of integrating ICT in different curriculum areas at the school level will help to understand the issues and areas for focused teacher development, to enable them to use technology to enhance teaching and learning in their classrooms. This study was done in a natural environment, that is, the school aiming at exploring the teachers' knowledge, beliefs and practices in integrating ICT in curriculum areas in a private secondary school in Karachi, Pakistan through a case study of four teachers. Methods of collecting data included classroom observations, stimulated recall interviews, informal conversations and analysis of documents. The use of stimulated recall interviews, that was not used by previous studies on teacher cognition, helped to make explicit teachers' tacit thinking underlying their observable actions. Data were analysed using QSR NUDI*IST, software for qualitative data analysis. Through classroom observations, followed by stimulated recall interviews, it was found that teachers' knowledge, beliefs and practices significantly influenced how they integrated ICT in the curriculum areas. Furthermore, it was revealed that there is a dialectical relationship amongst teachers' knowledge, beliefs and practices. However, in some cases, it was difficult to identify the relationship to any degree of certainty. Due to time limitations, the study could not trace how the teachers' knowledge, beliefs and practices changed over time. A longitudinal study is recommended to trace the changes in teachers' knowledge, beliefs and practices in regard to use of ICT over a longer period of time.