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Home > Role of Melatonin in Mitigating Salt Stress in Maize Zea Mays L.

Role of Melatonin in Mitigating Salt Stress in Maize Zea Mays L.

Thesis Info

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Author

Muhammad Ali

Program

PhD

Institute

The Islamia University of Bahawalpur

City

Bahawalpur

Province

Punjab

Country

Pakistan

Thesis Completing Year

2019

Thesis Completion Status

Completed

Subject

Agricultural Technology

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10211/1/Muhammad_Ali_Soil_Sci_2019_IUB_12.04.2019.docx

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727118719

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Soil salinity is a major yield reducing factor that limits plant growth in their natural habitat. It is an ever increasing problem in arid to semi arid regions that represent 40 % of total earth land. To meet the increasing global demand of food and to meet nutritional requirement of rapidly growing population, there is a need to develop salt tolerant genotypes that are able to grow and produce maximum yield on saline soils. Melatonin (N-acetyl-5methoxytryptamine) is a crucial biological hormone whose antioxidant capacity fortifies a number of plant species against salt stress. To investigate the effects of salt stress on maize hybrids growth, physiological, ionic and biochemical attributes and possible acclimation of maize hybrids against deleterious effects of salinity, two solution culture, one pot study and one field experiment were conducted. Initially 10 maize hybrids were screened in solution culture against four salinity levels (control, 40 mM L-1, 80 mM L-1 and 120 mM L-1). On the basis of biomass accumulation, water relations and K+/Na+ ratio, maize hybrid 2225 and 1574 emerged as salt tolerant while maize hybrid 8441 and 8711 as salt sensitive. Subsequently, physiology and biochemistry of maize hybrids of both categories were evaluated in another solution culture experiment with interactive salinity and melatonin levels and two maize hybrids 2225 (salt tolerant) and 8711 (salt sensitive) were further evaluated in soil culture (pot study) and in saline field with two melatonin levels 0.5 µM L-1and 1 µM L-1. Salt stress significantly reduced plant dry matter accumulation, relative water contents (RWC), membrane stability index (MSI), chlorophyll contents, plant nutrition and photosynthetic parameters along with inferior antioxidant enzymes activities. Melatonin application significantly alleviates the detrimental effects of salinity by regulating plant physiology, improving plant morphology, civilizing photosynthetic activity and activities of antioxidant enzymes.Maize hybrid 2225 conspicuously responds to melatonin application and exhibits improved growth under low and elevated salt stress. Our results suggested that melatonin induced salt tolerance in maize hybrids. Furthermore salt tolerant maize hybrids can serve as a potential source to get sustainable production from salt affected lands however, there is still much that need to be elucidated in future.
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5اردو شاعری میں قدرتی مظاہر کی تصویر کش

اردو شاعری میں قدرتی مظاہر کی تصویر کشی

ڈاکٹر عبدالمنان چیمہ

اردو شاعری کا ایک  اہم پہلو قدرتی  مظاہر و مناظر  کی تصویر کشی  ہے ۔ ایک طرف  شاعر کی اندرونی  کیفیت  ہوتی ہے اور دوسری طرف وسیع و عریض  کائنات اور اس کے بکھرے ہوئے حسین  قدرتی  مظاہر کا منظر ہوتا ہے۔اردو ادب کے  بہت سارے مشاہیر نے   فطرت نگاری کو اپنی شاعری کا موضوع بنایا ہے۔ ان کے ہاں  فطرت کے حسن کا ذکر ملتا ہے۔ جن قدرتی  اشیاء کا تذکرہ کرتے ہیں ان میں اپنی دلی کیفیات کا رنگ بھر دیتے ہیں۔ فطرت نگاری میں شاعر اپنی  دلی کیفیات و محسوسات  کو قدرتی نظاروں سے  ہم آہنگ کرتا ہے۔ عصر حاضر میں پیسے کی دوڑ  اور  صنعتی انقلاب  نے کائنات کے  حسین مناظر کو  شدید خطرے سے دوچار  کر دیا ہے۔

زمین پر بڑھتی ہوئی  آلودگی  کا انسان  ، جانداروں اورماحول پر نقصان دہ اثر پڑرہاہے۔اس کی بڑی وجہ قدرتی عناصر کا غیر دانشمندانہ استعمال ہے۔ اس لیے قدرتی وسائل  میں انسان کی مداخلت  کو کم کرنا اور روک تھام  کے لئے کردار ادا کرنا وقت کی اہم  ضرورت ہے۔زمین کی آلودگی نہ صرف انسانوں کی صحت کے لئے خطرناک ہے بلکہ موجودہ  دور میں سرمایہ دارانہ فکر کا حامل انسان معاشی خوشحالی کے چکر میں نسل انسانی کے ساتھ ساتھ  کرہ  ارض پر پائی جانے والی  دیگر مخلوقات    کو بھی  بری طرح متاثر  کررہا ہے۔  بہت سارے  مشاہیر نے اپنی شاعری میں  قدرتی عناصر کے استحصال  اور ماحولیاتی آلودگی کی مذمت کی ہے۔ اردو ادب کے مشاہیرکا  اس قومی وانسانی خدمت  اور قدرتی مظاہر سے محبت کو اجاگر کرنے کی ضرورت ہے۔

ظفر اقبال ظفر   قدرتی مظاہر کی تباہی   میں انسان کے کردار کی  منظر کشی کرتے ہوئے لکھتے  ہیں :

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نبی کریم ﷺ کے "نسب مطہرہ" سے متعلق مارگولیتھ کے خیالات کا تنقیدی جائزہ

This research article is based upon critical analysis of D.S Margoliouth’s indictment regarding pious lineage “Nasb e Muṭahharra”. Generally Orientalists have tried to affect the image of the Prophet Muḥammad (s.a.w) and prevailed uncertainties. It affects a large number of Muslim Scholars, intellectuals and youngsters because Orientals’ are well aware that Muslims cannot be defeated in battle-fields unless they are defeated in the field of faith and ideology. Our aim is to protect less aware Muslims, intellectuals and youngsters form the pseudo and grimy views of the Orientalists. Like other prejudice Orientalists D.S. Margoliouth have also indictments regarding lineage (Nasb e Muṭahharra) in his book “Muḥammad and The Rise of   Islam”.  Margoliouth argue with texts of Qur’ān and Ḥadith, without having any relation with the passage, to identify the essence of his ill well, hatred and prejudice with in the eyes of Muslims and common readers at large. This article concern five allegations of D.S. Margoliouth on the lineage “Nasb e Muṭahharra” and concludes that he failed to maintain his objectivity in the description of lineage “Nasb e Muṭahharra”.

Coherent Control of the Goos-Hänchen Shift

Coherent Control of the Goos-Hänchen Shift The coherent control of the Goos-Hänchen (GH) shift has been investigated when a probe light is incident on a cavity which contains dispersive atomic medium. We consider different atom-field configurations for the intracavity atomic medium, i.e., electromagnetically induced transparency (EIT), Raman gain process and double L (duplicated two-level). The sub- and super-luminal pulse propagations which correspond to normal and anomalous dispersion, respectively, through a dispersive atomic medium can be coherently controlled without changing the structure. This is due to the manipulation of group index of the dispersive atomic medium via different parameters associated with the driving fields, i.e., intensity, detuning and phase shift. In this research thesis, we use these facts and report coherent control of the GH shift in the reflected and transmitted light when the light is incident on a cavity containing dispersive atomic medium. The positive and negative GH shifts in the reflected and transmitted light corresponding to the sub- and super-luminal propagation of the pulse, respectively, could be observed. We consider a cavity which is consisted of an intracavity medium and two dielectric slabs being the walls of the cavity. The thickness of each dielectric slab is d 1 and length of the intracavity medium is d 2 , i.e., the total length of the cavity is L = 2d 1 + d 2 . A TE-plane polarized probe light is incident on the cavity. We consider two types of intracavity media, i.e., three- and four-level EIT atomic configuration. Following the EIT configuration of the atom-field system inside the cavity, we observe a coherent control of the GH shifts via the intensity and detuning of the driving fields. We observe negative and positive GH shift in the reflected beam via intensity of the driving fields, however, only positive GH shift is observed in the transmitted light. This is due to the fact that the group index of the cavity which includes the dielectric slabs and intracavity medium becomes negative and positive for the corresponding negative and positive group index of the intracavity medium, respectively, however, it remains positive for the transmitted light. xTo reduce the strong absorption during super-luminal propagation of light, we suggest a gain-assisted model to control the GH shifts which is experimentally more viable scheme. In this scheme, a similar kind of control over sup- and sub- luminal light propagation can be achieved using three- and four-level atoms inside the cavity following one and two-photon Raman transitions. Both atomic systems exhibit gain-assisted super-luminal propagation of the light. First we consider three-level atomic system and observe a control over GH shift in the reflected and transmitted light via probe field detuning and intensity of the control field using three-level system. We observe negative GH shifts in the transmitted light and both positive and negative GH shift in the reflected light via manipulation of the optical susceptibility of the atomic medium. This is again due to the fact that the group index of the total cavity remains negative for the transmitted light whereas it could be positive and negative for the reflected light. Next, we consider four-level atomic system with N-type configuration and study the behavior of spatial as well as angular GH shifts for different choices of the control field. Finally, we consider a duplicated two-level atomic system, which is a degenerated double lambda system, inside the cavity and study the GH shift behavior corresponding to the super- and sub-luminal propagation of an incident Gaussian- shaped probe light. The system has a coherent control over the group velocity via the phase shift associated with the driving and probe fields and is independent of the intensity of the field in the low optical regime. We study influence of the width of the incident Gaussian probe light on GH shift and distortion. We observe a strong dependence of the GH shift and distortion of the pulse on the width of the incident light.