Agricultural Biotechnology
Year:2015 | Volume:14 | Issue:1|Papers Count:12

Opium poppy (Papaver somniferum) is one of the oldest and most important medicinal plants due to biosynthesis and storage of Benzylisoquinoline alkaloids. For more biotechnology exploitation of this plant, optimization of tissue culture and genetic transformation is necessary. Among different factors affecting on genetic transformation, selectable marker and it's interaction with other factors is important. In order to optimization of gene transformation by agrobacterium to the plant, three separate experiments were designed for callus induction from hypocotyl, cotyledon and root explants. The factorial experiments were designed for callus induction with two factors based on completely randomized design with 8 replicates. First factor was basal medium (B5 and MS) and second factor was plant growth regulation (1mg/l 2, 4-D and 0.5 2, 4-D mg/l+0.5 BA mg/l). Analysis of variance and mean comparisons revealed that the highest percentage of callugenesis was observed in B5 Medium. At somatic embryogenesis stage, factorial experiments (with tree factors including medium, hormones and kanamycin) were performed based on completely randomized design with 8 replicates. Results indicated that the most embrygenesis and regeneration of somatic embryonic obtained from hypocotyl explants on B5 medium supplemented with 1 mg/l 2, 4-D and 25 mg/l Kanamaycin.

In order to identify quantitaive trait loci (QTLs) associated with morphological traits including number of leaves, leaf length, leaf width, leaf area, leaf fresh weight, leaf dry weight, plant height and stem diameter in oriental type tobacco, a genetic population comprising 100 F2 individuals from a cross between two oriental type genotypes, namely Basma seres 31 (maternal) x SPT 406 (paternal) was evaluated under field conditions. Subsequently a linkage map based on 23 simple sequence repeat (SSR) markers and 29 inter simple sequence repeat (ISSR) markers was constructed which covered 570.8 cM of tobacco genome. Composite interval mapping could identify 11 QTLs involved in controlling the investigated traits. The maximum percentage of phenotypic variance (R2) explained by QTLs was 25.2%. In this study, no QTL was identified for number of leaves. The results showed the existence of co-localized QTLs for some of the studied traits including plant height, leaf length, stem diameter and leaf dry weight which enhances the efficiency of marker-assisted selection in tobacco breeding programs.

Apical and auxiliary buds of six cultivars of hazelnut were prepared in different seasons, and disinfected with different treatments (including sodium hypochlorite, silver nanoparticles supplementary disinfectant and mercuric chloride) and then were cultured on solidified MS medium. The percentage of bacterial or fungal infected and developed explants were recorded. In addition, the effect of different levels of BAP and IBA on the establishment and growth of explants were evaluated. The results indicated that silver nanoparticles was effective in reducing in-vitro microbial contamination of hazelnut explants, and caused minimal injuries to the growing tissues. In spring, the lowest bacterial and fungal infections, with the highest percentage of shoot growth were obtained in 2.5% sodium hypochlorite for 10 min and submergence of explants into 100 mg/l silver nanoparticles solution for 30 or 45 min after 2.5% sodium hypochlorite for 5 min. MS medium supplemented with 1 mg/l BAP and 0.01 mg/l IBA produced the highest percentage of shoot growth (47.22), number of leaves (6.22) and shoot length (1.87 cm), which was significantly higher than the other levels of BAP. While in summer and autumn, the lowest percentage of bacterial and fungal infection and the highest percentage of shoot growth were obtained with submergence of explants into 100 or 150 mg/l silver nanoparticles solution for 120 min after 2.5% sodium for 20 min. The highest percentage of shoot growth was observed in MS medium containing 3 or 5 mg/l BAP and 0.01 mg/l IBA.

Horizontal submerged agarose gel electrophoresis of nucleic acids is a basic tool of modern molecular biology. This method is quick and easy and the use of that does not require too much skills. Separation of small fragments of DNA and molecular proteins are not possible with agarose gel efficiently, so that acrylamide gel is used for the above mentioned aims. Vertical polyacrylamide gel electrophoresis, which is costly, time consuming with hard handling. Recently, a method of horizontal polyacrylamide gel electrophoresis was introduced which requires especial equipment. In this study, we used the agarose electrophoresis tank with changes for small DNA fragments of SSR markers separation by horizontal polyacrylamide gel electrophoresis. In this method, horizontal electrophoresis performed using by a two-part gel prepared with agarose and polyacrylamide. The results showed the very sharp bands and in addition, in this electrophoresis method air bubbles not formed and cause reduction rupturing in the gel by glasses separation. New devised electrophoresis system can be applied for two aims, agarose and polyacrylamide gels electrophoresis.

Christ’s thorn is one of important medicinal trees with many valued medicinal properties that in folklore medicinally have a special position in Iran. Nowadays, usage of biotechnology in breeding and proliferation of Christ’s thorn is prevalent and it is necessary to be improved the regeneration using optimize explants and hormone combinations. In order to evaluation the performance of node, leaf and root explants and the effect of different hormonal combinations on three phases of callus induction, regeneration and rooting of Christ’s thorn this study has been carried out in 2013 at biotechnology laboratory of Sari Agricultural Sciences and Natural Resources University. For callus induction, explants of aseptic seedlings were cultured on MS medium containing 2, 4-D, NAA, TDZ and BAP in three levels (0.5, 1, 2 mg/l). Then, produced calluses were taken on MS medium containing different levels of BAP, TDZ and Kin (1, 3, 5 mg/l) and for rooting of seedlings 1.2MS medium containing IBA and NAA (0.5, 1, 2 mg/l) were used. The treatments were arranged in factorial based on completely randomized design with four replications. The results showed that the highest rate of callogenesis was observed in leaf explants on MS medium containing 2, 4-D at concentrations of 0.5 mg/l (0±10). While, the shoot regeneration obtained from callus produced on node explant by 5 mg/l Kin (10.03±8.84) and 1 mg/l TDZ (1.08±8.95) better as regards to callus produced on leaf and root explants. The rooting rate produced by IBA (90.6%) better than NAA (58%) at all concentrations of the hormone. According to the mentioned results Christ’s thorn than in vitro culture and regeneration show good response. The results can be used for various purposes, including reproduction and production of active ingredient in vitro culture.

During 2010 and 2011, 24 Xanthomonas strains were isolated from infected walnut trees from different regions of Fars and Lorestan provinces. For investigation of phenotypic and genotypic features, physiological, biochemical tests and rep-PCR with BOX, ERIC and REP primers. Isolates were rod-shaped, motile with polar flagella, gram negative, obligate parasite, oxidative negative, catalase positive and hydrolyzed esculin. All isolates produced H2S from cystein and acid from glucose, sucrose, D-mannose and D-sorbitol. Isolates showed differences in some characteristics such as tween 80 hydrolysis, starch hydrolysis, tolerance to 3% Nacl and utilization of L-alanin. Also pathogenicity tests and antibiogram were carried out. Based on phenotypic features, pathogenicity tests and amplification of 413 bp fragment with rev_seq R and rev_seq f primers in PCR assay, the isolates were identified as Xanthomonas arboricola pv. juglandis. Based on numerical analysis of phenotypic features most of the isolates were homogeneous and had about 87% similarity. The isolates divided into two groups on the basis of rep-PCR with BOX, ERIC and REP primers. Rep-PCR with above mentioned primers did not confirm clustering of theses isolates based on geographic origin. This is the first report of bacterial blight disease of walnut in Fars province of Iran.

Lepidium draba L. is a perennial weed belongs to the Brassicaceae family, contains considerably amount of glucoraphanin from glucosinolates group. Hydrolysis of this metabolite via myrosinase activity produce an isothiocyanate named sulforaphane that has various anticancer properties. It has been shown that environmental conditions such as temperature and altitude affect the biosynthesis level of secondary metabolites. In the present study, mature plants of L. draba was collected from different ecotypes of Kerman province [Mahan, Baft, Jiroft (Sardooiyeh)] and then sulforaphane content of each parts (root, leaf, flower and fruit) was measured using High Performance Liquid Chromatography. The results showed that fruits have the maximum amount of this compound, followed by flowers, leaves and roots. Also, the sulforaphane content in all organs of the plants where collected from Mahan was higher than two other cities. Based on the higher temperature and lower altitude of Mahan compared to the other cities, it deduced that these factors have significant effects on biosynthesis level of this active ingredient.

Due to uncontrolled crosses, the genetic purity of sheep breeds has changed. Therefore, using of genetic markers of mitochondrial sequencing is one the ways to study these changes. This experiment carried out to evaluate the diversity of HVR-I region from mtDNA in Afshari sheep breed. For conducting this study, the blood samples were collected from 20 unrelated Afshari sheep breed. After DNA extraction, this region of mtDNA was amplified with specific primers using PCR, and then the desired region was sequenced. After analyzing the data, 5 genetic haplotypes were determined in the studied population. Then the HRV-I region of Afshari breed were compared with other sheep breeds and results showed that this breed belongs to haplogroup A. The phylogenetic tree showed that this breed has the lowest genetic distance from other two Iranian sheep breeds (Balochi and Moghani). It can be concluded that Ovis orial may be the origin of Afshari and other Iranian sheep breeds.

Olive (Olea europaea) is one of the most important horticultural crops in Iran. Total area of olive production has increased about thirty times since 15 years ago in Iran. Dezful is one of the commercial olive cultivars that are well adapted to south regions of Iran and suitable for canning and oil production. Cuttings of this cultivar are difficult to root and asexual propagation by conventional methods is difficult and does not allow original clones to be obtained in industrial quantities. Micropropagation is a reliable technology applied commercially worldwide, which allows large-scale plant multiplication. This research was carried out to study the effects of different concentrations of BA, nutrient media, carbohydrate sources and gelling agents on shoot multiplication of olive cv. Dezfoul. Shoot tips and nodal segments of current season growth shoots of adult trees were used as explants. Based on the results of experiments, woody plant medium (WPM) containing 2.0 mgl-1 BA and 0.005 mgl-1 IBA was optimum for shoot multiplication. Woody plant medium was significantly better than MS or MS with half strength macronutrients for in vitro production of shoots. Sucrose at 30 gl-1 was significantly better than glucose or fructose for shoot fresh weight, number of shoots and main shoot length. Phytagel at 2.4 gl-1 was optimum for solidifying of nutrient medium.

The hazelnut is one of the major world nut crops and Iran stands in eighth place of its word production. This plant usually is propagated by layering and seed propagation of hazelnut is done rarely owing to hard seed coat and internal dormancy of the seeds. In vitro seed germination can be useful to hazelnut propagation in short time and production of improved cultivars. In this experiment, the effects of light (darkness, light-darkness), pretreatment (cold and GA3), seed form (complete and halved seed) and medium (MS, 1412”>MS, WPM and RMS) have been investigated on seed germination, root length and shoot height. The results showed that seed germination of hazelnut occurred only in darkness and the culture of halved seeds after cold pretreatment on 1412”>MS had the maximum seed germination, while the highest root length (10.8 cm) was obtained by complete seed in MS medium and without pretreatment (control). Also, the maximum height of the shoots (6.9 cm) was obtained by complete seed in RMS medium and without pretreatment. Overall, in vitro culture of the hazelnut seeds, in comparison with classic seed culture in pot, improved the seed germination and the plant production.

Soil salinity limits crop production and affects developmental aspects at first Leading to reduced plant production. In this study, gene expression analysis based on cDNA-AFLP technique was used to compare the expression profiles of NaCl stress at three levels, 1 week after subculture: 0 (control), 200mM and 400mM, in roots of Aeluropus littoralis which is the closest family to cereal. Among 32 isolated ESTs, 25 ESTs were obtained with the average length of 250 bp. The nucleotide sequences were compared with those in the GenBank database. Approximately 80% of the ESTs show homology to nucleotide or amino acid sequences in the GenBank database and 7 ESTs show no significant similarity in the GenBank database which considered as novel genes. Finally, 25 ESTs were recorded in NCBI database which are included potassium transporter, ribosomal protein, NADH dehydrogenase and golgin. The result of this research is very important to understand molecular basis and resistance mechanisms of drought stress for breeding and genetic engineering to improve crop resistance against stress and the production of resistant plants.

Take-all disease caused by the fungus Gaeumannomyces graminis (Sacc.) Arx & Oliver var. tritici Walker is the most devastating root disease of cereals throughout the world and it has been reported from different regions of Iran including Kermanshah province. During 2010-2011, diseased samples showing white head were collected from more than 300 wheat and barley fields visited in various parts of Kermanshah province. The pathogen were recovered from diseased samples collected from 139 fields representing prevalence of take all disease in nearly half (45 percent) of visited farms. Based on geographical distribution, ninety seven isolates of G. graminis were selected for further investigation. Two sets of primer pairs (NS5: GGT-RP and NS5: GGA-RP) were used to confirm identification and differentiation of the isolates. Eighty four out of 97 isolates produced 410 bp fragments when genomic DNAs were amplified with primer pair (NS5: GGT-RP) and 400 bp fragments with primer pair (NS5: GGA-RP) confirming the identification of the isolates as G. graminis var. tritici. But, 13 isolates did not amplify any bands. To study the genetic diversity of isolates of G. graminis var. tritici, 54 isolates were selected according to their geographical origins. Genetic diversity of selected isolates was studied using ISSR markers. Tenoutof 20 ISSR primers with high polymorphism and reproducibility were selected for further studies. Cluster analysis of DNA fingerprint profiles at the best cut off point divided the isolates into three groups, but there was no clear relationship between molecular cluster grouping and geographical distribution. The results showed that ISSR marker is an appropriate marker for genetic diversity studies in isolates of G. graminis var. tritici.