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Home > Utilization of the Triticeae Primary Gene Pool to Improve Drought Tolerance in Bread Wheat Triticum Aestivum L.

Utilization of the Triticeae Primary Gene Pool to Improve Drought Tolerance in Bread Wheat Triticum Aestivum L.

Thesis Info

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Author

Ahmad Ali

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/123456789/2531/1/2580S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727653839

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Among abiotic stresses, drought is the most important environmental factor limiting wheat yield and the problem need a genetic solution by bringing diversity in the existing wheat gene pool. Further, better understanding of crop responses to drought stress is a prerequisite for any breeding program. Screening of wheat germplasm comprising 26 synthetic derived (SBW), 24 conventional (CBW) bread wheats and 5 check cultivars (CCT) for drought tolerance was carried out through morpho- physiological and biochemical traits in hydroponics where stress was induced with PEG. Mean values for genotypes and treatments differed highly for all the studied traits. Drought stress resulted in increased osmoprotectants and antioxidant enzymatic activities. The germplasm was evaluated for phenological traits in the field under well- watered and drought stress conditions imposed at pre anthesis stage for two successive growing seasons during 2010/2011 and 2011/2012 crop cycles. Genotypic variations, variation due to treatment and interactions between them were much prominent depicting the widest genetic background possessed by the studied germplasm. Overall, the performance of SBW was quite promising when compared to check cultivars. Some potential drought tolerant lines including AA19, AA24, AA28 and AA46 are recommended for further micro-yield trials by Wheat Program, WWC and its national collaborators. The germplasm was also evaluated for glutenin compositions and key quality parameters. Grain quality analyses have provided a stringent selection sieve to select the drought tolerant genotypes with desirable end-quality characteristics. Several unique D- genome encoded HMW-GS were found along with favorable alleles at A- and B- genomes. D-genome encoded subunit Dx5+Dy10 which is known to encode superior grain quality attributes was observed in 63.6% genotypes followed by 1Dx2+1Dy12 (30.9%). Apart from HMW-GS, PCR based allele specific markers were used to identify allelic variation at Glu-3 loci (LMW-GS), which had a significant effect on visco-elastic properties of wheat dough. Several combinations of favorable LMW-GS alleles were observed at Glu-A3 and Glu-B3 loci. Key quality parameters like protein, sedimentation volume and carotenoids differed significantly within genotypes. Results established significant variability in quality characteristics and glutenin composition among D-genome synthetic-hexaploid wheat derivatives as compared to conventional bread wheat germplasm suggestive of their ability to improve quality traits in bread wheat. The germplasm was genotyped with 101 SSR markers for assessing its genetic diversity. Marker-trait association analysis was employed to identify SSR markers associated with traits related to drought. The stable estimate for the sub-populations (1- 20) was carried out with Structure Software 2.2. TASSEL 2.0.1 was used to calculate Kinship Coefficients Matrix. Association mapping was performed using Q-matrix as covariates and K-matrix (relatedness relationship coefficients) by applying the general linear model and the mixed linear model. In total, 61 marker–trait associations significant in both models were detected at p<0.01. The intra-chromosomal position/location of several of these MTAs coincided with those previously reported whereas some were unique that had not been located to date. Opportunities for further wheat improvement are provided by these novel loci/MTAs based on a marker approach.
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تمھارے ساتھ کے سب استخارے چھوٹ گئے

تمھارے ساتھ کے سب استخارے چھوٹ گئے
ملے ہیں درد خوشی کے سہارے چھوٹ گئے

ہمارے حصے میں آئے جفا کے سب موسم
وفا کریں گے جو کہتے تھے سارے چھوٹ گئے

نظر نظر میں دیے سب نے کتنے درد ہمیں
سرور و لطف کے تھے جو نظارے چھوٹ گئے

ہماری نائو کے درپے بھنور ہزار ہوئے
جو منزلوں کا نشاں تھے کنارے چھوٹ گئے

ہے پور پور میں ٹھہرا فضاؔ کی درد نیا
خوشی کے لمحے جو مل کے گزارے چھوٹ گئے

روایاتِ اسباب النزول کے تفسیری ادب پر اثرات کا جائزہ

Sabab al-Nuzūl (cause of revelation) in Qur'anic studies means the time, context, cause, and the situation in which Allah has revealed verses. Cause of revelation has an important role in the interpretation of Qur’ān. Nevertheless, most of the verses and suras of Qur’ān are revealed independent of events, these verses are revealed to fulfill the general aim of Waḥī which is the guidance of people. Such knowledge is an invaluable tool for grasping the meaning of this type of Qur’ānic verse. Many Muslim scholars consider the studying of Asbāb alNuzūl and their related discussions as necessary. Some exegetes have written books studying the subject. The earliest and the most important work in this genre is undoubtedly Kitab Asbāb al-Nuzūl (Book of Occasions of Revelation) of ‘Alī bin Aḥmad al-Wāḥidī (d. 1075 CE). Another important work is by al-Suyūṭī (d. 1505 CE) which is a slight improvement of al-Wāḥidī’s book. In this paper descriptive method and comparative study are used to analysis traditions of revelation and their effects on Tafsīr literature. This paper proves the value of the causes of revelation in Qur’ānic Interptation and their effects on Tafsīr Literature, so that verification and authencity of traditions of causes of revelation are mandatory for Tafsīr.

Nutritional and Antioxidant Analysis of Selected Wild Edible Fruits in Pakistan.

The wild edible fruit (WEFs) occupy key position among economically important plants throughout the world. The use of WEFs seems more common and widespread in food insecure countries including underdeveloped and developing countries. Many species of WEFs plays important in curing various disorders due to diversity of bioactive compounds including antioxidants. Pakistan has rich diversity of WEFs commonly grows in tropical, sub-tropical, temperate and alpine forests, plains and deserts of the country. The present study is aimed to analyze the nutritional and antioxidant potential commonly used WEFs with special emphasis on mineral diversity, proximate composition, energy content, bioactive compounds (Ascorbic acids and carotenoids) and free radical scavenging activity using various assays. During field surveys, Important WEFs were collected from various regions of Pakistan and identified using flora of Pakistan. The fully ripened fruits were processed and preserved using good laboratory practices. In analytical methods, minerals including P, Na, K, Ca, Mg, Fe, Mn, Zn, Pb, Ni, Co, Cd, Cr and Cu) were determined by using Atomic Absorption Spectrophotometer. Proximate composition including Moisture Content (MC), Dry Matter (DM), Ash Content (AC), Crude Lipids (CL), Total Dietary Fibre (TDF), Crude Proteins (CP), Total Available Carbohydrates (TAC) and Gross Calorific Value (GCV) were determined using standard methods. Free radical scavenging activity was determined using different assays including Trolox Equivalent Antioxidant Capacity (TEAC), Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picrylhydrazyl Scavenging (DPPH) and Phosphomolybdenium Reduction (PMR). For confirmation of potential compounds, Ascorbic acids and carotenoids were determined using HPLC techniques. a total of 23 WEFs belonging to 12 families commonly used in Pakistan were selected. Most of the species belong Rosaceae and Moraceae (4pecies) followed by Capprifoliaceae and Solanaceae (represented 4 species). The majority of species showed rich content of Potassium (K) except Opuntia ficus-indica and Opuntia monacantha having Calcium whereas Solena amplexicaulis, Rosa moschata Rosa webbiana and Rubus anatolicus were rich in Phosphorus (P). Among heavy metals, Cd was detected in Sambucus wightiana, Pistacia khinjuk, Lonicera quinquelocularis, Ribes orientale. In proximate composition, majority of WEFs showed highest percentage of moisture content except Sambucus wightiana having dry matter ((85.17 ± 4.902%). The highest free energy was reported in Pistacia khinjuk (580.82±13.03 k.cal/100g DW) followed by Rosa moschata (418.02±20.7 k.cal/100g DW). The highest vitamin C (Ascorbic acid) was determined in Rubus anatolicus (740.72±50.32 mg/100g) followed by Rosa webbiana (669.17±56.08 mg). In free radical scavenging activities of WEFs, aqueous extracts showed maximum antioxidant activities. The commonly isolated carotenoids were alltrans-β-cryptoxanthin, β-carotene-5, 6-epoxide, all-trans-ɛ-carotene, all-trans-γ- carotene, all-trans-β-carotene and 13-cis-β-carotene. The present study provides baseline data on commonly used WEFs in rural communities of Pakistan. The study concludes that reported species are enriched with nutrients that can fulfil the nutrition requirements among human populations.