Refine search
Results 1-10 of 19
Comparative Studies on Gene Expression of Rice and Wheat in Response to Fungal Infection
2019
Nermin Mohamed
Cereals are the foremost necessary foods for growing population of human. Wheat (Triticum aestivum) is the first important and strategic cereal crop for the majority of world’s populations. It is the most necessary staple food. Although rice (oryzae sativa) has the second place because of planted area but it serves as the most important food source for Asian countries. Wheat and rice production may be severely restricted by biotic and abiotic constraints. Disease is the major biotic stress in several regions.Comparative sequence analysis is a powerful tool to study homologous gene families, define conserved gene functions between orthologs, and identify lineage- and species-specific genes. Most annotations of newly sequenced genomes are based on similarity with sequences for which functional information is available. Apart from conserved sequences, inter-species differences provide important clues about evolutionary history and species-specific adaptations. In our study, two RNA-sequencing data sets of resistant variety of wheat (Triticum aestivum L.,) after infection with leaf rust fungus, Puccinia triticina and resistant variety of rice (Oryza sativa L.,) after infection with blast fungus, Magnaporthe oryzae were compared. 31768 up-regulated genes in wheat and 3902 up-regulated genes in rice were filtered according to fold change more than 3 and removing variants, 250 upregulated genes of wheat and rice were aligned and phylogenetic tree was generated. The result of phylogenetic tree showed close relationship between ten aligned gene pairs of wheat and rice. Two pairs of aligned gene pairs were selected randomly, super family of these pairs were obtained, the result showed that each aligned pair of proteins shared the same protein family and the same annotation and all pairs participate in plant defense pathways. Then, the gene expression of the two pairs were validated by Real-time PCR after infecting wheat with Puccinia triticina and rice with Magnaporthe grisea. Each aligned pair of the two pairs shared the same manner of expression with few exceptions in rice.
Show more [+] Less [-]HEAT TOLERANCE IN SOME BREAD WHEAT GENOTYPES UNDER TWO SOWING DATES
2018
Asmaa Badr | M. Ahmed | A. Esmail | M. Rashed
A 7x7 half diallel cross along with their parental wheat cultivars were evaluated under two sowing dates (19th Nov. and 17th Dec.).The results revealed that mean squares due to sowing dates, genotypes and genotypes x sowing dates interaction were significant for most of the studied traits. Delaying sowing date to Dec. reduced all studied characters compared to the normal sowing date except electrolyte leakage which increased by delaying sowing date. Heterosis over better parents showed that, the best hybrids under stress condition were Misr 2 X Giza 168 and Sids 1 X Giza 168 for grain yield / plant and some of other studied traits. General and specific combining ability mean squares indicated the importance of both additive and non-additive gene effects in the inheritance of the studied traits with few exceptions. However, the additive effect was more important than the non-additive effects in the inheritance of days to 50% heading, plant height, No. of spikes/ plant,No. of kernels / spike and 1000-kernel weight while, the non-additive effects were more important than the additive effects in the inheritance of electrolyte leakage and flag leaf area. The best general combiner parents for grain yield / plant and some of other studied traits were Gemmeiza 11 and Giza 168under stress condition. The best hybrids for SCA effects were Sakha 93 X Sids 1, Gemmeiza 11 X Giza 168, Misr 2 X Giza 168 and Sids 1 X Giza 168 under stress condition for grain yield / plant and some of other studied traits. The crosses Gemmeiza 11 X Giza 168 (HSI 0.36), Gemmeiza 7 X Giza 168 (HSI 0.58) and Sakha 93 X Giza 168 (HSI 0.60) have recorded the lowest values of heat susceptibility index (HSI), indicating their tolerance to heat stress (late sowing date).
Show more [+] Less [-]HETEROSIS AND COMBINING ABILITY OF SOME BREAD WHEAT GENOTYPES
2018
A. Hassan | M. Ahmed | M. Rashed
Twenty one wheat hybrids and their seven parental genotypes were evaluated in the research farm of the Faculty of Agriculture, Ain shams University, Shoubra El-khema, Cairo, Egypt, in 2016/2017 growing season. The genetic analysis was conducted using Griffing (1956), Method 2, model 1). Significant differences among parent genotypes and their 21 crosses for all the studied traits (days to 50% heading, days to maturity, flag leaf area, plant height, number of spikes/ plant, spike length, number of spikelets/ spike, number of kernels/ spike, 1000-kernel weight and grain yield/ plant) were detected. This indicated that, variability exists among these populations may increase the chance appearance of good new combination that can be isolated in the succeeding generations. Parents versus crosses mean squares as an indication for average heterosis over all crosses were significant for all studied traits. Mean squares of general (GCA) and specific (SCA) combining abilities were significant for all studied traits except spike length trait for SCA which was insignificant. GCA/SCA ratios were more than unity for all studied traits, which indicating that the additive type of gene action is of great importance in the inheritance of these traits. Heterosis over the better parents showed that, the best hybrids were Gemmiza 9xGiza 168, Sakha 93x Giza, 168, Sakha 94x Jawahir-14, Sakha 94x Bob white, Giza 168xAcsad 925 and Jawahir-14x Bob white for grain yield/ plant trait and some of the other studied traits. The best general combiner parents were Sakha 94, Jawahir-14 and Bob white for grain yield/ plant trait and some of the other studied traits. The best SCA hybrids were Gemmiza 9x Sakha 93, Gemmiza 9x Giza 168, Sakha 93x Jawahir-14, Sakha 94xJawahir-14, Sakha 94x Acsad 925, Sakha 94xBob white, Giza 168x Jawahir-14, Giza 168x Acsad 925, Jawahir-14x Bob white and Acsad 925x Bob white for grain yield/ plant trait and some of the other studied traits. These result could be used in wheat breeding programs.
Show more [+] Less [-]FORECASTING WHEAT CROP PRODUCTION IN THE DESERT GOVERNORATES
2016
Hanan Ghaly
Wheat is considered one of the main grain crop that human is depend in his diet all over the world. It is a strategic crop globally and locally in Egypt. The problem of the research refers to the gap between local wheat production and consumption. This gap forced the country to import wheat and thus represent a burden on the Egyptian balance of trade. It is the objective of the present paper is therefore to investigate ways to alleviate the deficit of wheat production and gap. The study assess wheat area, production and productivity during the period 1995-2013 particularly in the desert governorates. The study estimates wheat gap during the above period by about 67.14 million ton. Safe efficiency is therefore was put as 54.1%. Losses of wheat were put as about 1017 about 14.2% in the country as a whole. The study estimates that wheat production in Matrooh and New Valley governorate is expected to be about 173.56 and 277.8 thousand ton respectively. The study suggests that measures should be taken to decrease losses of wheat during harvesting and marketing. New storage facilities should be established. The study recommends that special concern should be given to wheat cultivation in desert governorate by encouraging former to grow wheat by covering good wheat price to encourage formers
Show more [+] Less [-]DOES SILICON ALLEVIATE the INJURIES of NITROGEN DEFICIENCY and FENOXAPROP–P–ETHYL HERBICIDE in WHEAT (Triticum aestivum, L.)?
2014
Saudy H. S. | Manal Mubarak
Si application alleviates influence of some abiotic stresses on crop plants. Meanwhile, scarce information is avaiable about the significance of Si for helping the plants to overcome the injuries of N deficiency and herbicides pressure. Thus, two–year 2–field experiments were carried out in wheat. Experiment I involved three Si concentrations (Si0ppm, Si250ppm and Si500ppm) and two N levels(N100% and N50%). Experiment II examined four combinations of fenoxaprop–p–ethyl and Si: fenoxaprop–p–ethyl+Si250ppm and fenoxaprop–p–ethyl+Si500ppm (each either in sequence or in tank mixture), fenoxaprop–p–ethyl alone, hand weeding and weedy check. Under N deficiency (N50%), Si500ppm increased plant height as compared to the control. No significant differences in SPAD values were detected amongst Si concentrations under each of the two tested N levels. Si can partially alleviate negative N deficiency effect on wheat yield, causing its increase to level obtained under normal N supply. Si has no effect on weed biomass when applied with fenoxaprop–p–ethyl either in sequence or in tank mixing. The most promising treatment for maximizing wheat grain yield was the application of 100 kg N ha–1 (N50%) x fenoxaprop–p–ethyl+Si250ppm in sequence", which also, in the same time, means reducing both cost of crop production and environment pollution.
Show more [+] Less [-]INFLUENCE OF TEMPERATURE ON THE DEVELOPMENTAL RATE AND REPRODUCTION OF THE ENGLISH GRAIN APH-ID, SITOBION avenae (FABRICIUS) (HOMOPTERA: APHIDI-DAE).
2006
Salman A.M.A.
A laboratory investigation was conducted to study the effect of constant tempera-ture on some biological aspects of english grain aphid, Sitobion avenae (Fabricius). The present work was carried out in electrical incubators provided with photoperiod of 16 : 8 (L : D) and 55 – 60% R.H. Data revealed that the english grain aphid passed through four instars to reach maturity. The duration period of the nymphal stage was 19.0, 13.98, 11.96, 8.51 and 7.5 days at 12, 15, 18, 21, 24 °C, respectively. Developmental threshold of this stage is found to be 4.2 °C. The thermal units re-quired for complete one generation was 148 day – degrees. Life table parameters were as following : The reproduction rate (Ro) were 18.75, 30.72, 36.53, 44.21 and 32.42; mean generation time (GT) were 26.16, 21.23, 17.39, 11.92 and 9.86 days; population doubling time (DT) of the english aphid were 6.19, 4.29, 3.35, 2.18 and 1.96; intrinsic rate of increase (rm) were 0.1121, 0.1613, 0.2069, 0.3178 and 0.3528 and finite rate of increase (λ) were 1.119, 1.175, 1.229, 1.374 and 1.423 at 12, 15, 18, 21 and 24 °C, respectively. The results indicated clearly that the favourable range temperature for development and multiplication the english grain aphid be-tween 18 and 24°C.
Show more [+] Less [-]EFFECT OF TOOTH PICK (AMMI visnaga L.) SEED EXTRACTS ON THE RICE WEEVIL SITOPHILUS oryzae (COLEOPTERA : CURCULIONIDAE)
2005
Salwa Ahmed | Nadra Al-Moajel
Seeds of the tooth pick plant (Ammi visnaga L.) were extracted by organic sol-vents of different polarities, and tested for their toxic effect on Sitophilus oryzae in-festing wheat grains. Toxicity of chloroform extract, was the most potent, at both Lc50 and Lc95 levels (i.e. 3240 and 8730 ppm). Reproductive potential of treated weevil were strongly affected as no progeny were obtained when treated with either Lc50 or Lc95 with A. visnaga. Extracts treatment at Lc95 level organic extract gave protection up to 12 weeks for petroleum ether and chloroform, and 9 weeks when acetone was used for extraction. All tested extracts reduced grain germination at the end of 14 weeks storage period. Also, treated wheat grains with tooth pick extracts reduced the weight loss of grains.
Show more [+] Less [-]GROWTH AND PRODUCTIVITY OF WHEAT PLANTS AS AFFECTED BY COMPLETE FOLIAR FERTILIZER COMPOUNDS UNDER WATER STRESS CONDITIONS IN NEWLY CULTIVATED SANDY LAND
2005
Ahmed A | M Ahmed
Two filed experiments were carried out at the New Salheyia Region, Sharkia Governorate, during the two successive seasons 2001/2002 and 2002/2003 to study growth and productivity of wheat plants as affected by complete foliar fertilizer compounds under water stress conditions in newly cultivated sandy land.
Show more [+] Less [-]EFFECT OF THE INTERRACTION BETWEEN NITROGEN, PHOSPHORUS AND POTASSIUM ON GROWTH CHARACTERS AND YIELD OF WHEAT UNDER DRY FARMING CONDITIONS
2005
Two field experiments were carried out at El-Khroub experimental station, east of Constantine, Algeria, to evaluate the effect of N, P, K fertilization and their interaction on growth characters and yield of wheat grown on calcareous soil. The design of each experiment was split-split plot. Urea was applied as folier application to one experiment to evaluate the supplementel application of nitrogen under dry farming conditions. The results showed that the main stem height, number and height of tillers and number of leaves were varried according to the levels of N, P, K fertilization as well as to presence or absence of urea., Straw yield significantly increased due to increasing nitrogen level and potassium fertilization in absence or presence of urea. However, grain yield was significantly increased either with increasing nitrogen level in absence of urea or with increasing phosphorus levels in absence or presence of urea. Straw yield was significantly affected by N * P interaction in absence or presence of urea and N * P * K when urea was applied. However, grain yield was significantly affected by N * P and N * P * K interractions in absence of urea application.
Show more [+] Less [-]POPULATION STRUCTURE AND GENOME-WIDE ASSOCIATION ANALYSIS FOR SALINITY TOLERANCE IN BREAD WHEAT USING SNP, SSR AND SCOT MARKER ASSAYS
2020
Alsamman Alsamman | S.D. Ibrahim | Mohamed Rashed | Ayman Atta | M.S. Ahmed | Alaa Hamwieh
Wheat is an essential staple food in the developing world, where demand is projected to grow exponentially in the future; simultaneously, climate changes are projected to reduce supply in the near future. One of the main consequences of climate change is salinity, which negatively impacts the world's cultivated area and therefore affects the global wheat production. Our objectives are to study the population structure of several Egyptian and international wheat accessions and to identify the genetic factors controlling the salinity stress response of bread wheat. In addition, we have attempt to identify genes that control some important agronomic parameters of wheat under salinity stress were identified. The wheat germplasm panel consisted of 70 accessions obtained from Egypt, Syria and Iran. The assessment of salinity tolerance was conducted over the years of 2018 and 2019 in the field and in the greenhouse. The genome association analysis (GWAS) and population structure analysis was conducted using six SCoT, five SSR and 93 SNP markers. Analysis of the population structure using allele frequency and phylogenetic analysis indicated that the studied wheat accessions were belong to four population groups. Where, for the most portion, Egyptian, Syrian and Iranian accessions are clustered depending on their country of origin. The GWAS analysis revealed 13 SNP markers that were significantly associated with morpho-agronomic wheat traits during salinity stress. These markers were closely related to genes that are known to have a direct link to wheat response to salinity stress such as CYP709B2, MDIS2, STAYGREEN, PIP5K9, and MSSP2 genes. This study revealed the genetic structure of adapted and imported wheat accessions, which could be used to select potential wheat accessions for local breeding programs. In addition, the SNP genotyping assay is a very potential technology that could be efficiently applied to detect genes that control bread wheat response to salinity stress.
Show more [+] Less [-]