مجله فنآوری زیستی در کشاورزی
سال یازدهم شماره 2 (زمستان 1391)

Fars province is one of the natural habitats of Pyrus syriaca in Iran. Harvesting of fruits، deforestation، expansion of agriculture and overgrazing in recent years imposed detrimental effects on natural regeneration of this species. This research was carried out to develop tissue culture techniques for easy، rapid and mass propagation of P. syriaca. Shoot tips and nodal segments of current season growth shoots of selected trees in Deh-Kohne open forest in Sepidan County، Fars province، Iran were used as explants. Cultures free of contamination were established on MS medium containing 0. 4 mgl-1 BA، 0. 01 mgl-1 IBA. Concentration of 0. 8 or 1. 0 mgl-1 BA was optimum for shoot multiplication. The best procedure for rooting of in vitro produced shoots consisted of two phases: in vitro root induction and ex vitro root development. For root induction، P. syriaca shoots were cultured on DKW medium (half strength macronutrients) containing 75 mgl-1 IBA and incubated in the darkness for 24 hours. For root development، shoots were transferred from root induction medium to moistened Jiffy-7 pots. Using this method 100 percentage of shoots rooted. Inclusion of 0. 1 mgl-1 BA in nutrient media had negative effects on rooting of P. syriaca shoots and significantly decreased rooting percentage.

Herbivore feeding induces two main defensive systems in plant, direct and indirect defenses. To know role of some genes which involve in direct and/or indirect defenses their expression pattern were compared in clean and mite infested leaves of some common bean susceptible (Akhtar) and resistant (Naz, Ks41128) genotypes with QRT-PCR. Then to proof the QRT PCR results, preference of predatory mite, Phytoseiulus persimilis، were compared in all cultivars with olfactometer. The QRT-PCR results indicated that among genes only expression of LOX gene that is important in both direct and indirect defenses was significantly difference among genotypes. After spider mite infestation expression of LOX gene was significantly up-regulated only in the resistant genotype (Naz) and in the susceptible genotype (Akhtar) expression of LOX was even significantly down-regulated. The result of olfactory tests showed that only Naz genotype could significantly attract more predatory mites after the spider mite infestation. Therefore significantly more attraction of predatory mite to resistance genotype (Naz) than other genotypes and up regulation of LOX gene in this genotype upon mite infestation can demonstrate role of this gene in direct and indirect defense of common bean against spider mite.

The effect of aqueous smoke extract derived from burning of Tanacetum parthenium leaves and GA3 on secondary dormancy breaking, germination and seedling growth of rapeseed seeds (Topaz and PF704 cultivars) was investigated in this study. In the first experiment the rapeseed seeds of two cultivars imbibed with different concentrations of aqueous smoke extract (0.0005, 0.001, 0.002, 0.004, 0.01, and 0.1 (v/v)) and distilled water (control) were investigated as a completely randomized factorial 2×7 with 3 replications. In second experiment difference concentrations of aqueous smoke extract (0.001, 0.002, 0.004, 0.01) and control (with out smoke water) combined with difference concentrations of GA3 (0, 0.1, 0.15, 0.20 mgl-1) were used in B5 regeneration medium. The experiment was arranged in a completely randomized design, factorial 5×4 with 3 replications. In the first experiment, use of aqueous smoke extract (concentration of 0.1) showed the highest germination percentage and shoot length in dormant seeds of both cultivars, while this concentration showed the highest root length in Topas cultivar. Use of GA3 (concentration of 0.1 and 0.20 mgl-1) in combination with aqueous smoke extract (0.1) showed the highest germination percentage in Topas, while use of GA3 (concentration of 0.1 and 0.15 mgl-1) combined with all aqueous smoke extract concentrations indicated the highest germination percentage in PF704 cultivar. In both cultivars, two concentrations of aqueous smoke extract (0.004 and 0.01) combined with GA3 (concentration of 0.1) in culture medium showed the highest shoot length and root length.

The aim of this study was to survey the association between the Prolactin gene and milk performance traits. In the study 145 Holstein cattle and 60 crossbred cattle were used. The frequencies of allele and genotype in Prolactin gene has been recognized through PCR-RFLP using RsaI restriction endonuclease in 294-bp fragment located in exon 4. The GG genotype had the highest frequency in Holstein and crossbred cattle (0.738 and 0.588 respectively). Also frequencies of allele A and G were 0.152 and 0.848 in Holstein and 0.233 and 0.767 in crossbred cattle. Holstein cattle with AG genotype showed the highest milk yield. Dairy cattle with genotype AA showed the highest protein percentage (P<0.05) while there were no significant differences between various genotype in this gene and other milk traits (P>0.05). This polymorphism effect was significant for milk yield and protein percentage. The results of this study showed that this polymorphism could be a marker for selection for milk yield and protein percentage used in the population.

Tenderness is one of the important characteristics of meat and desired to consumers. MYF5 gene has a key role in the regulating of formation and development of skeletal muscle and considered as a candidate gene associated with growth and meat quality characteristics. In this study blood samples from 180 camels; include 40 Camelus Bactrinus and 140 Camelus deramedarius was randomly collected. To ascertain whether there was variation in the camel MYF5 gene, we have developed a method of PCR-single-strand conformational polymorphism (PCR-SSCP) analysis. In this study, exon 1 region of the MYF5 gene were investigated and four unique SSCP patterns observed. Two SNPs were detected with substitution of A/G and G/A in 97 and 367 position, respectively that create four haplotypes, related to banding patterns. In comparison to the other populations of one humped camels, genetic divergence between populations showed that Bactrian camels have a greater genetic distance.

Cyclotides-like proteins are a family of small disulfide-rich and plant-derived peptides made up of ~30 amino acids. They contain a unique structural motif that consists of a head-to-tail cyclic backbone and knotted arrangement of three disulfide bonds, together referred to as the cyclic cystine knot (CCK). The cyclotides are antimicrobial circular peptides that have a variety of biological activities such as anti-HIV, anti-tumor, cytotoxic, hemolytic activity and etc. In current study, we have cloned new members of the cyclotide-like gene family from Zea Mays leaf cDNA using 3'RACE-PCR and specefic primers based on sequences found in a continuous region of homology present in EST database. Clones were randomly picked and sequenced. Nine cyclotide-like genes were identified. Phylogenetic analysis divided them in two separate classes; first class with length 300-500nt showed similarity with classical cyclotide-like genes in databases. In contrast the other class was very different with length 90-500nt and showed variations in number of disulfide bands. The cloning of these genes in maize showed that they are very diverse and may have important role in plant response to different stresses.

Septoria tritici blotch (STB), caused by Mycosphaerella graminicola (anamorph Septoria tritici), is one of the most important diseases of wheat (Triticum aestivum) world wide. planting resistant cultivars is the best method to manage STB environmentally. Many plant genes are induced or repressed and many others are up regulated or down-regulated to response a pathogen. In this study, Real time PCR were used to analysis of expression patterns of five genes involved in septoria leaf blotch resistance in wheat. After inoculation of resistant (Wang shui bai) and susceptible (Falat) cultivars with M. graminicola fungus, expression of these genes were investigated at 11 time points in 3 replications and the expression patterns of them were determined as relative to 18s reference gene. Comparision of these sequences using NCBI data base showed that these sequences had homology to neomenthol dehydrogenase, Lucine rich repeat protein kinase, natural resistance-associated macrophage protein, alpha 1,4-glucan phosphorylase and Tubby-like F-box protein. The peak expression for 1,4-glucan phosphorylase and Lucine rich repeat protein kinase were at 3 hours after inoculation and for neomenthol dehydrogenase the peak is at 12h. For natural resistance-associated macrophage protein the peak was at 3h but it was decreased and then increased again at second day. Tubby-like F-box protein was induced at 3h and had significant expression in this time but the peak expression for this gene was at 3 day after inoculation and we can call this pattern, a bimodal one. Some of these genes were induced early after inoculation and their expression increased significantly, but some others showed an induced expression several days after inoculation.