Search or add a thesis

Advanced Search (Beta)
Home > Physiological and Molecular Characterization of Two Genetically Diverse Spring Wheat Triticum Aestivum L. Cultivars for Salt Tolerance

Physiological and Molecular Characterization of Two Genetically Diverse Spring Wheat Triticum Aestivum L. Cultivars for Salt Tolerance

Thesis Info

Access Option

External Link

Author

Ashraf, Muhammad Arslan

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2012

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1233

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726905240

Similar


Hydroponic experiments were conducted to appraise variation in the salt tolerance potential of two wheat cultivars (salt tolerant, S-24 and moderately salt sensitive MH-97) at different growth stages. Salinity stress caused a marked reduction in plant biomass and grain yield of both wheat cultivars. However, cv. S-24 was superior to cv. MH-97 in maintaining higher plant biomass and grain yield under saline stress. Furthermore, salinity caused a significant variation in different physiological attributes measured at different growth stages. For example, salt stress caused a marked reduction in net photosynthetic and transpiration rate in both wheat cultivars but to a varying extent at different growth stages. Higher photosynthetic and transpiration rates were recorded at the boot stage than at other growth stages in both wheat cultivars. The response of other gas exchange attributes was also variable at different growth stages. Salt sensitive wheat cultivar MH-97 was more prone to salt-induced adverse effects on gas exchange attributes as compared to cv. S-24. Salt stress caused considerable reduction in different water relation attributes of wheat plants. A significant reduction in leaf water, osmotic and turgor potentials was recorded in both wheat cultivars at different growth stages. Maximal reduction in leaf water potential was recorded at the reproductive stage in both wheat cultivars. In contrast, maximal turgor potential was observed at the boot stage. Salt-induced adverse effects of salinity on different water relation attributes were more prominent in cv. MH-97 as compared to those in cv. S-24. The integrity of PS II was greatly perturbed in both wheat cultivars at different growth stages and this salt-induced damage to PS II was more in cv. MH-97. A significant alteration in different biochemical attributes was also observed in both wheat cultivars at different growth stages. For example, salt stress caused a substantial decrease in chlorophyll pigments, ascorbic acid, phenolics and tocopherols. In contrast, it increased the endogenous levels of ROS (H2O2), MDA, total soluble proteins, proline, glycine betaine and activities of enzymatic antioxidants (SOD, POD, CAT, APX). These biochemical attributes exhibited significant salt-induced variation at different growth stages in both wheat cultivars. For example, maximum accumulation of glycine betaine and proline was recorded at the early growth stages (vegetative and boot). However, cv. S-24 showed higher accumulation of these two organic osmolytes and this could be the reason for maintenance of higher turgor than that of cv. MH-97 under stress conditions. The activities of various enzymatic antioxidants increased markedly in both wheat cultivars, particularly at the vegetative stage. However, cv. S-24 exhibited consistent increase in the activities of various enzymatic antioxidants, whereas, this phenomena occurred erratically in cv. MH-97 at different growth stages. Salt stress significantly increased the endogenous levels of toxic ions (Na+and Cl-) and decreased essential cations (K+ and Ca2+) in both wheat cultivars at different growth stages. Furthermore, K+/Na+ and Ca2+/Na+ ratios decreased markedly due to salt stress in both wheat cultivars at different growth stages and this salt-induced reduction was more prominent in cv. MH-97. Moreover, higher K+/Na+ and Ca2+/Na+ ratios were recorded at early growth stages in both wheat cultivars. It can be inferred from the results that wheat plants are more prone to adverse effects of salinity stress at early growth stages than that at the reproductive stage.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

۲۹۔ ہم کیسے جی رہے ہیں ؟

ہم کیسے جی رہے ہیں؟

ہم زندگی سے بھاگے ہوئے

نجانے کدھر جا رہے ہیں

ہمیں کچھ خبر نہیںہے

اپنی محرومیوں میں رنگ بھر نے کی خاطر

سفید لمحوں میں جی رہے ہیں

موت بھی ہم پر ترس کھاتی ہے

ہم بھی کیا جی رہے ہیں ؟

 آنکھوں کو بند کیے

تشنہ ہونٹوں کو سیے ہوئے

مگر کیا کیجیے

تہذیب اسلامی كی عالمگیریت

Now a days while Globalization has become talk of the street and through the knowledge explosion and media coverage and access it apparently seems that the world has really squeezed into a globe in hand. Before the terminology of Globalization World Order was introduced after the Gulf War. From there onwards different interpretations were presented by the people aiming World Orders, Globalization off which the international hegemony of Super Power is the right one. To achieve the goal of dominating the world and controlling all the resources became the target of Globalization. By this way Globalization became a dangerous weapon for humankind. Therefore protests and demonstrations were seen against the unwanted designs of Globalization. In this article on one hand new meanings of Globalization are introduced and on the other hand the deep rooted constructive aspect of Islamic Globalization is introduced in comparison with Western Globalization. In this way this article presents an interesting study of two civilizations

Physiological Responses of Field Grown Lemongrass Cymbopogon Citratus to Seasonal Changes

A population of lemongrass (Cymbopogon citratus) was investigated in this research for changes in metabolite profiles in the leaves of different ages i.e. penultimate (second fully expanded leaf from the top), middle (a leaf from the central position of a tiller) and bottom (a lowermost green leaf on a tiller) with changing seasons round the year for two consecutive years (2010-2011). Measurements were made for some primary and secondary metabolites while the essential oils profile of leaves was analyzed using GC-MS. The photosynthetic pigments displayed sharp variations in the leaves of different ages with changes in the environmental conditions. Higher chlorophyll a, b and carotenoid were recorded during summer months. The accumulation trends of osmolytes in lemongrass showed notable seasonal variation. The accumulation of total free amino acids, free proline and GB were higher during summer months. The antioxidant enzymes minimized the effect of oxidative damage by scavenging H 2 O 2 and reuced MDA contents in extreme environmental conditions especially during summer. The younger leaves of lemongrass exhibited much higher concentrations of vitamins as compared to bottom leaves. The secondary metabolites i.e. alkaloid, phenolic and flavonoid contents in lemongrass leaves were markedly increased with increased temperature. Seasonal variation affected the nutritional profile of lemongrass substantially. The production of NDF ADF, ADL, cellulose and starch was greater during summer. Cellulose and silica contents were higher in bottom leaf possibly due to plant aging. Starch content was higher in penultimate leaf, which declined with leaf age. Mineral concentration of lemongrass appears to be largely dependent on temperature and evapotranspiration. The GC-MS analysis of lemongrass oil carried out in the leaf samples collected during January, April, July and October revealed that out of 54 compounds analyzed, neral, citral, geranial, allerthin, caryophyllene oxide were major ones synthesized in various sesasons.