مجله بیوتکنولوژی کشاورزی
پیاپی 2 (زمستان 1388)

Septoria leaf blotch is one of the most important wheat diseases worldwide includingIran. To study the genetic diversity of Iranian isolates of Septoria tritici, the infected samples were collected from Khuzestan, Golestan, Ardebil and Kermanshah provinces. Twenty six out of 88 recovered isolates were selected according to their geographical origins for studying virulence and their genetic diversity using RAPD analysis. Analysis of virulence of disease severity data was statistically significant at 99% confidence level (p<0.01). Comparison ofthe means of disease severity, using Duncan’s multiple range test, divided the isolates into five groups. In genetic diversity studies, Six out of 15 random primers were polymorphic and reproducible. Cluster analysis of DNA fingerprint data using UPGMA method and Jaccard's coefficient, divided the isolates into 8 groups at 35% similarity level showing a high genetic diversity among Iranian populations of S. tritici. According to number of clusters in which the isolates of each region were placed, the highest genetic diversity belonged to Ardebil. This is the first report on the study of genetic diversity of Iranian populations of S. tritici.

Identification of plant cultivars and rootstocks, requires accurate andreproducible methods which not affected by environmental conditions. In thisresearch, efficacy of SSR markers in identification of some apple genotypes androotstocks was studied. For this purpose, 5 pairs of SSR markers were applied foridentification of 24 and 5 Iranian and foreign apple genotypes and rootstocks,respectively. According to the results, 52 polymorphic alleles were proliferated in 5microsatellite loci (mean 10.4 alleles per locus) and polymorphism informationcontent (PIC) was 80%. The markers produced specific DNA bands in "Lobnani(tabestane)", "Golab (Damavand)", "Golab (Isfahan)", "Malyer 8" and "Malayer 9"genotypes and specific band patterns in "Bahare arak", "Shemirani", "Lobnani(tabestane) ", "Damavand B1", "Golabn (rasmi) ", "Golab (damavnd) ", "Golab(sahne) ", "Malayer 8", "Malayer 6", "Malayer 9", "Shafiabadi (chalus) and "Golab(paize) ". In rootstocks, 12 specific and reproducible alleles were identified. Theresults indicate the high efficacy of SSR markers for apple cultivar and rootstockidentification.

Sessile marine invertebrates produce toxins to deter or kill predators andcompetitors. In recent years, biomedical exploitation of these bioproducts, organismavailability for mass production, and limited stock in their natural habitats have beenserious obstacles hindering benefit from these organisms. Cultivation of theseinvertebrates, is one of various approaches for producing the large biomass required. Inthis report, results of a preliminary study on the captive symbiotic soft coral Sinulariaflexibilis, the richest species within its genus, are presented. Using asexual propagation ofthis species, fragments of the coral were established in a cultivation tank. These coralsamples showed absolute survival (100%, n=24) within 16 weeks, high specific growthrates (17-21×10−3d−1), and a minimum doubling time of 6 weeks in the laboratory. Inaddition, biosynthesis of major bioactive compound of this species, flexibilide, continuedin a range of 0.1-0.25 mg g−1 dry weight. Considering high potential of the Iraniansouthern waters and the diversity of similar marine organisms, it is important to applymarine biotechnology for substantial exploitation of these potential resources.

Asiatic citrus canker caused by Xanthomonas citri subsp. citri is a bacterialdisease with economic importance in tropical and subtropical citrus-producing areas.One of the potential reaction of plants to pathogens attack is an increased levels ofpathogenesis-related proteins such as chitinase and β - 1,3 -glucanase. The objectiveof present study was to investigate the expression of the PR proteins; β-1,3-glucanaseand chitinase in Washington Navel orange (Citrus sinensis) inoculated withXanthomonas citri sub sp.citri. Quantitative reverse transcription-polymerase chainreaction was used to quantify the mRNA level of chitinase and ß- 1,3 -glucanasegenes in early stage of plant defense response. For this purpose, total RNA wasextracted from inoculated and non inoculated citrus plants at different times postinoculation.Higher amounts of transcripts were detected 24 hours after pathogeninoculation of citrus leaves and four-fold more than the control citrus plant. Thetranscript levels of the two genes were reduced with the time after inoculation, anddecreased significantly at 96 hours post inoculation. This study indicated that the roleof chitinase gene is more than glucanase in early stage of citrus canker disease.

Reserving genetic diversity in native chicken breeds of Iran because of little populationsize is necessary for breeding goals and increasing their production. The first step isdetermination of genetic diversity in existing populations. Studying mitochondrial HVR-I cangive useful information about genetic diversity in those populations. This study was carried out for determination of the mitochondrial HVR-I sequence in Mazandarani native chicken in Iran, estimation of genetic diversity and determining its phylogenetic relationship with other chicken breeds. Blood samples were taken randomly from 20 birds. After extracting DNA, HVR-I region was amplified with specific primers and after purification was sequenced. From 20 primary sequences, 19 were sequenced properly. The phylogenic tree was drawn with consensus sequence of Mazandarani breed and other similar sequences of different chicken breeds obtained from GenBank. In the phylogenic tree, the Mazandarani breed was clustered with Iranian Marandi native chicken, Azarbayjan native, white Leghorn, Barred Plymouth rock, Silky and Sonerati breeds. Then, it can be concluded that Mazandarani breed has some genetic similarities with these chicken breeds.

Protein phosphatase 2C family consists of a group of evolutionary conservedserine/threonine phosphatases which play a role in stress signal transduction. A subfamily of these protein phosphatases in Arabidopsis, including ABI1 and ABI2, are known ascomponents of ABA signal transduction pathway. Nine OsPP2C proteins were found in rice(OsPP2C1 to OsPP2C9), carrying all the conserved motifs of this subfamily. Among them,only OsPP2C5 transcript levels were significantly up-regulated by drought and abscisic acidwhich is down-regulated by re-watering or ABA removal. In this research, we investigated the effect of drought (180 mM mannitol), salt (100 mM NaCl) and cold (15°C) stresses onOsPP2C5 gene expression in 2-days-old seedlings of FL478, IR29 by semi quantitative RTPCR and Real time PCR methods. The expression levels of OsPP2C5 gene in both cultivars were upregulated by cold and drought stresses compared to control and salt treatment. Three alternative transcripts were identified based on the achieved results by semi quantitative RTPCR and the alignment of the reported sequences for OsPP2C5 gene including cDNA and ESTs. The expression of two transcripts amplifiable by the used primers in semi quantitative RT-PCR method were detected in both cultivars while the transcript levels of the bigger transcript was more in IR29 and the transcript levels of the smaller one (original transcript) was higher in FL478 (under drought and cold stress). It seems the transcript type and the expression level is correlated with the cultivar sensitivity to the respected stress.

Oilseed crops such as rapeseed have the important role in the production ofenergy for humans. The most important part of plant breeding programsunderstanding of genetic diversity to classify population based on different markersfor selecting the suitable parents. In this research, genetic diversity of 16 genotypes ofrapeseed was evaluated using SDS-PAGE protein markers and morpho-physiologicaltraits in the field and laboratory conditions. Extraction of leaf proteins was performedbefore physiological maturity and then concentration of proteins was measured byBradford method. For separating and patterning of the extracted proteins, SDS-PAGEtechnique via poly acrylamide electrophoresis was used. After staining of proteins bycoomassie blue R-250 and scoring of the bands, cluster analysis was computed basedon Jaccard coefficient which that the genotypes classified into 2 separate groups.Results of cluster analysis based on agronomical traits shown that the studiedgenotypes classified into 5 groups. Correlation between morphological and moleculartraits was assessed using Mantel test and significant positive correlation was observedbetween them. Thus according to genetic distances between the genotypes, we can use cross between Milena and Dante for obtain the highest amount of heterosis in futurebreeding program and hybridization between Opera and Sahara based on morphophysiological markers according to similarity coefficient is justified.