Reem Mohsen Abd El-Razek Abd El-Maksoud
University: Ain Shams
Date : 2015
Isolation and Characterization of Drought Tolerance-Related Gene(S) in Barley.
Differential display-polymerase chain reaction (DD-PCR) technique was used to analyze differentially expressed sequence tags (ESTs) in barley (Hordeum vulgare L.) cultivar Giza 126 under drought stress. An array of 66 differentially expressed EST and 74 EST fragments were obtained from roots and shoots, respectively. The sequences of these fragments were identified and determined using a bioinformatics approach; BLAST. Results of the database sequence alignment for roots identified 28 (42%) fragments showed homology with some predicted proteins, 12 (18%) fragments showed homology with predicted proteins under abscisic acid (ABA), 7 (11%) fragments showed homology with predicted proteins under low temperature, 10 (15%) fragments showed homology with transcription factors, 5 (8%) fragments showed homology with different enzymes, 3 (5%) fragments showed homology with unidentifying clones and one (1%) fragment showed homology with LEA protein. With regard to shoots, 34 (46%) fragments showed homology with some predicted proteins, 13 (18%) fragments showed homology with predicted proteins under abscisic acid (ABA), 4 (5%) fragments showed homology with predicted proteins under low temperature, 4 (5%) fragments showed homology with transcription factors, 7 (10%) fragments showed homology with different enzymes, 8 (11%) fragments showed homology with un-identified clones, 3 (4%) fragments showed homology to different genes and one (1%) fragment showed homology with 14-3-3 protein. These results could be used to improve abiotic stress tolerance of economic crops. It is therefore evident from the aforementioned discussion that this study has revealed some important aspects associated closely with environmental tolerance (drought) in barley which could be used for the elucidation of mechanisms underlying environmental molecular stress responses in other major strategic cereal crops.
Key Words: Drought stress, Differential Display-Polymerase Chain Reaction (DD-PCR), EST, Gene expression, Hordeum vulgare L.
HOSSAM MOHAMED ZAKARIA
Date : 2015
Genetic Transformation in Strawberry to Produce Virus Resistant Plants
Strawberry (Fragaria ananassa) is an economically important soft fruit crop with polyploidy genome, which makes the breeding of new cultivars difficult. Simple and efficient method for transformation and regeneration is required for cultivar improvement in strawberry. In the present study, adventitious shoot regeneration has been investigated in three cultivated strawberry varieties, i.e., Festival, Sweet Charlie and Florida via direct organogenesis protocol using the in vitro juvenile leaves as explants. To select the suitable organogenesis Protocol, the explants of the three cultivars were cultured on MS medium supplemented with different concentrations of TDZ (1, 2 and 3 mg/l), and incubated at a temperature of 22°C ± 2. Medium containing 2 mg/l TDZ revealed the best regeneration efficiency with the three cultivars (73.3% for cultivar Sweet Charlie, and 72.6% for both cultivars Festival and Florida). After 4 weeks, the produced shoots were cultured on MS medium with different concentrations of BA and Kin to enhance shoots elongation. Results showed that the medium SE6 containing 1.5 mg/l BA & 0.5 mg/l Kin was the best for cultivars Festival and Sweet Charlie, while, medium SE5 containing 1.5 mg/l BA & 0.1 mg/l Kin was the best for the cultivar Florida. Elongated shoots were successfully rooted by incubating the shoots on MS medium containing 1.5 mg/l NAA for 4 weeks. Furthermore, transformation of the cultivars, Festival and Sweet Charlie has been established via Agrobacterium strain LBA4404 containing the plasmid pISV2678 with both Gus- intron and Bar genes. Three days post co-cultivation, GUS activity was screened using the histochemical assay. The presence of the both trans genes was detected by PCR using specific primers for each gene. Strawberry explants were transformed with pGPSL124 with shRNA constructs to acquire virus resistance. The construct was designed to suppress three of the viral genes C1, C2 and C4, which are expressed at early stages of viral life cycle. Transgenic plants were confirmed for transformation through PCR, Southern blot analysis.
Key words: Strawberry, Regeneration, Organogenesis, Transformation, GUS, bar, Agrobacterium tumefaciens, shRNA constructs.
Ahmed ElFatih Amin ElDoliefy
Factuality: Agriculture and Applied Science
University: North Dakota State
Date : 2015
Molecular Mapping of Fusarium Head Bligh Resistance in Tow Adapted Spring Wheat Cultivars
Releasing bread wheat (Triticum aestivum) cultivars with resistance to Fusarium head blight (FHB) disease can be endangered by narrowing the variation in genetic sources. However, resistance to FHB rely on five different types. FHB resistance types I, II, III, IV and V were assessed in field and greenhouse under multiple locations and years experiment’s combination. In our study, the genetic of FHB resistance in two widely cultivated hard red spring wheat varieties (‘Glenn’ and ‘Parshall’) were dissected. The specific objectives of the study were to generate recombinant inbred lines (RIL) populations, phenotypic assessment for FHB resistance, different informative genotypic marker data, genetic map, and finally QTL analysis. For Glenn/MN00216-4 (GM) population, 112 RIL were developed; while for Parshall/Reeder (PR) population, 110 RIL were developed. The RIL, checks and the two parents were evaluated for five FHBrelated
and one agronomic-related traits over two to six environments in North Dakota, Minnesota, and South Dakota. Two genetic maps were developed covering 2,229 cM of length using 645 DArT markers for GM population, and 470.4 cM length using 154 DArT/SNP combined markers for PR population. Composite interval mapping identified 37 QTL for the GM population, and 10 QTL for the PR population. Results showed that Glenn lacks the major consistent (Fhb1 and Fhb5A) QTL from the Chinese source Sumai3, while acquired (Fhb2). Parshall proved to be domestic with no exotic resistance background, though it acquired similar genomic regions to Fhb2 of Sumai3. PR genome contains five major QTL including three novel QTL with multiple FHB resistance and two with stable effect (1AS and 4BL) across at least two environments. Along with these previously identified QTL for FHB resistance, in both populations, new QTL were also identified such as Fhb-1B1L.c and 7D1S.b in Glenn, and Fhb.5AL, 7AS and 4BL in Parshall. In conclusion, our study added to the wheat genome, two genetic maps, new QTL for FHB resistance and two germplasms with new recombination for QTL and/or resistance sources. Finally, Glenn and Parshall can be of great importance if implemented in wheat enhancement and molecular assisted breeding programs nationally and internationally.