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Home > Relative Physiological and Biochemical Evaluation of Some Tomato Lycopersicon Esculentum L. Genotypes under Water Deficit Conditions

Relative Physiological and Biochemical Evaluation of Some Tomato Lycopersicon Esculentum L. Genotypes under Water Deficit Conditions

Thesis Info

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Author

Shamim, Fakhra

Program

PhD

Institute

Pir Mehr Ali Shah Arid Agriculture University

City

Rawalpindi

Province

Punjab

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2392/1/2840S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727078563

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Water stress or drought is the most important factor limiting tomato (Solanum lycopersicum L.) productivity in arid and semi-arid regions of the world. A better understanding about the mechanism of water stress tolerance provides basic strategies for crop breeding for drought tolerance. One hundred and twenty genotypes of tomato were evaluated and ranked for drought tolerance at seed germination and seedling stage under stress induced by polyethylene glycol (molecular weight of 8000) at 2.5%, 5.0% and 7.5% (w/w) concentrations. Further, based on simple and multiple selection criterions, eleven genotypes were selected to determine biochemical indicators for drought tolerance through growth, yield and physiological responses under water stress of 80%, 60% and 40% field capacity at the vegetative and reproductive stages. Two-week-old genotypes were subjected to various levels of PEG8000-imposed water stress (Control, 5%, 10% and 15%) for a period of two weeks. Chlorophyll fluorescence, gas exchange characteristics were measured and A/Ci curve was drawn to further understand underlying mechanism of water stress tolerance in different tomato genotypes. Studies were carried out at PMAS-Arid Agriculture University, Rawalpindi in collaboration with National Agricultural Research Centre Islamabad, Pakistan and The University of Manchester, England. Overall, it was found that some tomato genotypes maintained their degree of water stress tolerance at different developmental growth stages. However, mechanism of water stress tolerance varies different tomato genotypes. The most important mechanism was dehydration avoidance characterized by significantly higher growth rate under water stress conditions. The second mechanism was efficient portioning of biomass characterized as higher growth and relatively lower yield under stress conditions. The third mechanism was osmotic adjustment characterized by higher accumulation of compatible solutes such as proline, soluble sugars, higher antioxidant capacity and photosynthetic activity. Water stress tolerant genotypes Lyallpur-1 and CLN1767 were most tolerant tomato genotypes characterized with higher growth, tomato yield, higher antioxidant and photosynthetic capacity. In conclusion, our results indicate that the selection based on growth and some physiological attributes like osmotic adjustment, antioxidant and photosynthetic capacity under appropriate water stress conditions similar to target environments are critically important for improving both drought tolerance and tomato yield potential which is of great commercial importance.
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پلاٹ

پلاٹ

                ناول کا پلاٹ بہت خوبصورت انداز میں گتھا ہوا ترتیب دیا گیا ہے۔ناطق جس پس ماندگی کو عیاں کرنے میں کامیاب رہے ہیں۔اسے شروع میں اس طرح دکھایا گیا ہے کہ اصل میں ایک معمولی جڑ کیسے ایک مضبوط تناور درخت  بن جاتی ہیاور جب اس تناور درخت نے اپنی جڑیں اور شاخیں پھیلا دی ہوتی ہیں۔تو اسے ہٹانا کتنا مشکل عمل ہے۔لوطی حرکات سے شروع ہوتی یہ کہانی پھر سیکس انڈسٹری تک جا پہنچی  یہ معاشرتی پس ماندگی ایک مضبوط جڑ کی  طرح معاشرے کو کھوکھلا کر رہی ہے۔اس نے بہت اعلیٰ طریقے سے پردہ سرکایا ہے۔کہانی کا پلاٹ  بہت مضبوط ومنظم ہے مصنف کی گرفت کہانی کے پلاٹ کے علاوہ مکالمے اور جزئیات نگاری پر بھی آخر تک قائم رہی۔تلخ حقائق کو نمایا ں کرنے میں ناطق نے ایک دلیرانہ جسارت کرکے معاشرے کے سماجی مسائل کی عکاسی کی ہے۔عظیم الشان صدیقی لکھتے ہیں :

’’کہانی اگر قصہ کی بنیاد ہے تو پلاٹ اس کی ترئین وآرائش ہیں‘‘(2)

                مصنف نے اس غیر عادلانہ اور استحصال پذیر معاشرے میں اپنی کہانی کیذریعے غیر انسانی رویوں کو بے نقاب کیا ہے اور اس بے حس معاشرے کی بہتری کے لئے ایک مضبوط پلاٹ مرتب کیا ہے۔جس میں شروع سے آخر تک مسلسل ایک سحر بھی قاری پہ قائم رہتا ہے اور دوسرا معاشرے میں موجود غیر انسانی رویوں اور اخلاقی پس ماندگیوں کو سمجھنے کے قابل ہوجاتا ہے۔

کردار

                ناطق کے ناول’’کماری والا‘‘میں تمام کردار متحرک دکھائی دیتے ہیں۔ ’’ضامن‘‘کہانی کا مرکزی کردار ہے۔’’طلال‘‘نے جو کردار پیش کیا یقیناوہ بھی ایک بھاری ذمہ داری پوری کر رہا ہے جس کی وجہ سے باقی تمام کردار متحرک دکھائی دیتے ہیں۔شروع میں قاری کو...

Western Parameters of Freedom of Expression: A Critique from Islamic Perspective

This study explores Western parameters and principles of freedom of expression from an Islamic perspective. Western thought advocates infinite freedom of speech but it also has some regulations, limits and restraints. Every Western human rights instrument and convention guarantee freedom of expression, but in fact, the excess of freedom is bringing the society to a harsh kind of clash and conflict. In simple words, freedom without sufficient legal and moral restrictions cannot be managed. It is also observed that without strict legal and moral boundaries, it cannot become fruitful for the state and society. Even the Western world, which is representative of maximum freedom of speech, also bounds freedom of expression with some parameters and restrictions. However, it is propagated that the Western laws provide outclass freedom of expression and speech. The actual situation is not as good as it is expressed, because on one hand, the international instruments provide freedom of speech and on the other, they limit it through certain laws. It means freedom of expression is not free of boundaries in the West also. In other words, it is only a mythology and controlled propaganda that the Western thought and civilization provides absolute and unlimited freedom of expression and press in their countries. Instead, Islamic teachings categorically agree to provide the right to freedom of expression but on the other hand, it binds them with some social, moral and legal boundaries to save the society from any kind of clash and conflict. It is perceived Western legal instruments limit freedom of expression with some legal boundaries and laws rather than ethics and morals. It is recommended on behalf of this study that the Western world also puts moral and religious boundaries on freedom of expression for its safety. An analytical & critical approach with qualitative research methodology is adopted in the study.

Fabrication and Characterization of Low Cost Electrodes for Fuel Cells

Fuel cell is an emerging, cleanest, environmental friendly and pollution free technology, which converts chemical energy of fuel into electricity, heat and power without combustion. Fuel cells are categorized according to their electrolytic materials and working temperature. Solid oxide fuel cell (SOFC) is the most dominant and prominent among the fuel cell family. In other words, fuel cell is one of the most competitive candidates that could provide possibly accomplishments. Conventionally, Ni-YSZ cermet anode is used in SOFC, which works in the temperature range of 800-1000oC. Although this anode possesses a high electrochemical activity, high performance as well as electronic conductivity yet it requires a high working temperature to achieve the optimal results. Its high working temperature is the present draw back which becomes a major barrier to its commercialization. If this cell has to be commercialized then there is need to find suitable electrode materials that can operate successfully at low operating temperature. Keeping this in mind, many new electrode materials have been introduced in the present work, which have been classified into two groups; one is containing Ni partially while the other is completely Ni free. New electrode materials were prepared by introducing nano technique using either dry or wet chemical method with an added advantage of low manufacturing temperature. In order to fabricate a complete fuel cell, the compatible electrolyte materials were also prepared by co-precipitation method. These materials exhibited an excellent performance at comparatively low temperature (400-600 oC). For SOFC electrode and electrolyte purpose, CuNiZnGdCe (CNZGC), Al0.1NixZn0.9-x (ANZ), Cu0.2Mn0.2Zn0.6 (CMZ), Ba0.05Cu0.25FexZn0.7-x (BCFZ) Ba0.15Fe0.10Ti0.15Zn0.60 (BFTZ), Ba0.4Sr0.6Co 0.3Mn0.7 (BSCM), La0.1Sr0.9Co0.2Zn0.8 (LSCZ), Na2CO3-K2CO3- Ca0.2Ce0.8 (NK-CDC) and Gd0.1Ce0.9-Y2O3 (Y-GDC) materials were successfully synthesized by solid state reaction method or wet chemical and co-precipitation method. These electrodes and electrolyte materials were characterized by XRD, SEM, TEM, electrochemical and electrical techniques. It has been found that the BCFZ-5 having a composition of Ba0.05Cu0.25Fe0.10Zn0.60 shows an electrical conductivity equal to 25.84 at hydrogen atmosphere. It also exhibited the maximum power density of 741.87mW/cm2 and 933.41mW/cm2 for symmetrical and asymmetrical fuel cell testing schemes. On the basis of these results, BCFZ-5 material is considered a promising electrode/anode candidate for low temperature solid oxide fuel cell. Different approaches have been implemented to reduce the present cost of electrode and electrolyte materials for solid oxide fuel cell. For example; I. II. Use of cheap raw material Lowering of sintering temperature III. Reduction of sintering time IV. Lowering of operating/working temperature It has been noted that the substitution of zinc compound Zn(NO3)2.6H2O in place of nickel oxide (NiO) has reduced the cost by a factor of ≈25 in addition to the lowering of manufacturing and operating temperature, which also reduces the cost indirectly by saving energy and time. Moreover, the cost has been further reduced by a factor of 35 and 18 when samarium nitrate Sm(NO3)3.6H2O and gadolinium nitrate Gd(NO3)3.6H2O are respectively replaced by calcium nitrate Ca(NO3)2.4H2O. The lowering of working temperature from 1000 to 550oC is a major achievement that would not only reduce the running cost yet it may help in commercialization of solid oxide fuel cell. In a nut shell the electrodes and electrolytes proposed in the present work have successfully lowered the manufacturing as well as working temperature and hence the operational cost along with a significant reduction in the manufacturing cost of solid oxide fuel cell (SOFC). Key words: Solid Oxide Fuel Cell (SOFC), Zn Based Electrodes, Nano-composites Electrodes, Energy Conversion Device, Ceria Carbonated Fuel Cell, Advanced Fuel Cell, Efficient Device, BCFZ anode, NKCDC electrolyte, Novel Cathode