Abstract The effect of silymarin as an active ingredient of milk thistle seed as an systemic acqu... more Abstract The effect of silymarin as an active ingredient of milk thistle seed as an systemic acquired resistance (SAR) substance in rice (Oryza sativa L.) against rice blast disease caused by Magnaporthae oryzae was investigated in this study. Silymarin is considered as a medication substance on human drug and has a metabolic and cell-regulating effect and scavenging oxygen radicals reactions. Results showed that, silymarin do not inhibits fungus linear growth in vitro. Significant improvement of resistance under greenhouse conditions with different concentrations 10, 25, 50, 125, 250, 500, 1000 and 2000 mg/L of silymarin was recorded. The most suitable concentration was 500 mg/L. The recorded disease severity was 23.5% when applied five days before inoculation and significantly reduced disease severity under field condition at both experimental seasons. Gene expression for some indicators for salicylic acid (SA) pathway such as OsWRKY45 and OsNPR1, jasmonic acid (JA) pathway such as AOS2, JAYMB and PBZ1 (OsPR10) and ethylene (ET) pathway such as ACO7 was studied. Salicylic acid effect on the pathway related to salicylic acid is evident through both genes (OsWRKY45 and OsNPR1), not jasmonic acid and ethylene pathways, while the effect of silymarin is not clear through the genes studied in all pathways. Finally, the results suggested that silymarin activates SAR at least in part by reinforcing basal plant defense responses on induced defense state.
Callus induction methods and plant regeneration system in six selected canola (Brassica napus) cu... more Callus induction methods and plant regeneration system in six selected canola (Brassica napus) cultivars“Serw-4, Pactol, Sakha-1, Line-99, Line-162 and Line-123" grown under Egyptian environment were investigated for drought stress. Biochemical and molecular characterization were the other goal for this study. Hypocotyl explants (5-7 mm) from sterile canola seedling were cultured on MS media with different concentrations of plant growth regulators. The results of callus induction varied with respect to treatments and genotypes. For B. napus, the use of hypocotyl explants resulted in a higher percentage of callus formation, ranging from 46 to 100% on different media. Moreover, among six tested media, MS6 (MS + 0.1 mg/l NAA + 0.5 mg/l Kin) gave the best results on average of callus induction percentage with 100% of explants producing callus for cv. Serw-4, Pactol, Sakha-1, Line-99 and Lin-123. Meanwhile, Line-162 recorded 94% for callus induction. The lowest responses were noted ...
Nine Egyptian rice ( Oryza sativa L.) genotypes were assessed for DNA polymorphism using three d... more Nine Egyptian rice ( Oryza sativa L.) genotypes were assessed for DNA polymorphism using three different types of molecular markers (RAPD, SCoT and SSR). RAPD primers produced 68.70% of polymorphism and an average PIC value of 0.24. SCoT primers generated 86.54% of polymorphism and 0.28 average value of PIC. All tested SSR markers yielded amplified products and generated 104 alleles (average 6.5 alleles/marker) with PIC values ranged from 0.20 to 0.49 per marker. RM301 SSR marker produced specific alleles only in the four drought sensitive rice varieties that could readily distinguished the sensitive genotypes from the others. While, RM20A and RM302 SSR markers produced one positive unique marker in the moderate (Sakha 102) and drought tolerant (Giza 178) varieties, respectively. These markers may be usefully exploited for molecular breeding of rice for drought tolerance. On the other hand, clustering analysis using UPGMA method classified the nine rice genotypes into three gr...
In an attempt to assess the genetic diversity among 18 maize inbred lines used in breeding progra... more In an attempt to assess the genetic diversity among 18 maize inbred lines used in breeding programs and to identify specific genetic markers for late wilt disease resistance, esterase, peroxidase and RAPD markers were used. Fifteen RAPD primers were successful for evaluation of 18 inbred lines of maize. These biochemical and molecular techniques were efficient in detecting genetic polymorphism with an average of 100, 100 and 83.21% for esterase, peroxidase and RAPD, respectively. For cluster analysis, the 18 inbred lines were divided into four groups based on esterase and peroxidase isozyme and three groups based on RAPD analysis. Also, the principal coordinate analysis separated the 18 inbred lines for three groups (esterase and peroxidase analyses) and two groups (RAPD analysis) and the separation was according to the imported location more than the late wilt disease resistance. On the other hand, 45 out of 2191 amplified bands were found to be useful as unique markers. All primer...
The negative effects of drought stress induced by mannitol on three different plant genera of gra... more The negative effects of drought stress induced by mannitol on three different plant genera of gramineae were studied. Identification of SSR markers for drought tolerance in gramineae was an important goal for this study. Four cultivars from three different plant genera of gramineae (rice, wheat and barley), two tolerant and two sensitive from each genus were treated with three different mannitol concentrations (125, 250 and 500 mM) in addition to control and incubated for three weeks in room temperature. Data were collected for three drought related important seedling traits (root length, shoot length and germination%). Significant differences for genotypes were revealed by analysis of variance for root length and shoot length in rice and barley cultivars. While in rice, wheat and barley, significant differences were observed in mannitol treatments. On the other hand, significant differences for shoot length only in rice cultivars were recorded for the interaction between genotypes ...
Assessment of DNA changes and mutations at molecular level are important in plant breeding. In th... more Assessment of DNA changes and mutations at molecular level are important in plant breeding. In this study DNA changes in four rice genotypes (Sakha-107, Giza-179, Sakha-106 and Sakha-101) induced by silica nanoparticles (0, 150, 300 and 450 ppm) and somaclonal variations were determined using RAPD and SSR analyses. The potential effects of SiO2NP (< 100 nm) on rice plant growth were studied and the results showed positive and negative effects. Application of SiO2NP enhanced the fresh weight, shoot length and root length of the drought-sensitive rice varieties, but number of roots/seedling was increased with high concentration (450 ppm) in all studied genotypes. Mature embryos of four rice genotypes were used as explant source for callus induction and plant regeneration system. The obtained results showed significant effect of genotype on callus induction and plant regeneration in rice. For assessment of genome template stability percentage (GTS%), five RAPD primers were used and ...
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Genetic Engineering by Aziza Aboulila
Genetics 229 by Aziza Aboulila
أساسيات الوراثة by Aziza Aboulila