Iranian Journal of Genetics and Plant Breeding
Volume:1 Issue: 1, Dec 2010

Pistachio is one of the most important horticultural products of Iran. The best way to get the maximum yield is to have genetically pure and monotonous gardens. Thereby، study of genetic variation and providing genetic identifications، make this possible to have homogenous gardens with high performance genotypes. In the present study، genetic diversity of 19 Iranian pistachio cultivars was assessed using ISSR and RAPD primers. Among these markers، RAPDs generated 127 amplification products، out of which 88 were polymorphic and ISSRs produced 114 amplification products، out of which 73 were polymorphic. RAPD fingerprinting detected more polymorphic loci (67%) than the ISSR (63%). Mean of polymorphism information content (PIC) for each of the marker systems (0. 39 for RAPD and 0. 39 for ISSR) suggested that both the marker systems were equally effective in determining polymorphisms. The dendrograms constructed using RAPD and ISSR marker systems were highly correlated with each other as revealed by high Mantel correlation (r= 0. 83). These two marker systems were found to be useful for genetic diversity studies in pistachio and identify variation within Pistacia vera cultivars.

Powdery mildew caused by Erysiphe necator، is one of the most economically damaging diseases of grapevine throughout the world. This is the first molecular biology study on this fungus in Iran. The aims of the present study were (a) to analyse genetic diversity between isolates of E. necator fungus in four main grape production regions in Iran، i. e.، Qazvin، Alamoot، Takestan and Shahriar and (b) to obtain an overview on the probable mating types of E. necator isolates infecting grapevines in the mentioned regions. In total، 11 RAPD primers were used، amongst which 7 primers showed high level of polymorphism. Out of 20 isolates، only 4 isolates were of mating type + and the rest were of mating type –. For statistical analysis، bands with molecular size between 180-2900 bp and high degree of polymorphism were chosen for analysis. Cluster analysis was carried out using Jaccard’s similarity coefficient، based on UPGMA that classified isolates into 7 groups.

Thioredoxins (Trxs) are small ubiquitous disulfide reductases that participate in dithiol-disulfide exchange reactions. In contrast to animals and prokaryotes that typically possess one or a few genes encoding Trxs، higher plants contain eight different Trx types: f، m، x، y، z، o، s، and h. Trx h with multiple forms is involved in different processes such as seed germination، cellular protection against oxidative stress، self-incompatibility etc. The expression analysis of the three h-type Trx genes، called VvTrx h1، VvTrx h2 and VvCxxS2 was studied in different tissues of three grape cultivars (Askari، Red Seedless and White Seedless) at various develpmental stages by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). The grape Trx h genes were expressed in berry، leaf، petiole، cluster، stem، root، and seed tissues at different developmental stages. The higher expression of the isoforms was observed in berry tissues as compared to those of the roots. In berry tissues، the expression of VvTrx h1، VvTrx h2 and VvCxxS2 isoforms were analyzed at six growth stages، including 14، 28، 42، 56، 82، and 110 days post anthesis (dpa). The highest level of expression was observed at veraison stage (56 dpa). The expression of grape Trx h genes was also analyzed in leaf، petiole and cluster tissues at three developmental stages including young، mid and old stages with a imprecise pattern of expression in comparison to the berry tissues. In contrast to VvTrx h1 and VvCxxS2 isoforms، VvTrx h2 showed the highest level of expression in different tissues، suggesting a major role for this isoform in grape.

GF677 rootstock (peach ×almond) is an important rootstock for peach. It was produced by Bernhard in French at Grand Farad Research Centre in 1965. The present study focused on the effect of some PGRs on propagation and root induction on GNH medium as part of providing an applicable protocol for micro-propagation of mentioned rootstock. Results indicated that BAP at concentration of 0.5 mg/l plus 0.1 mg/l IBA produced the highest normal auxiliary shoots. Media supplemented with ZR produced only single shoots. The greatest rate of rooting (up to 40%) was obtained from induction medium containing 2 mg/l of IBA.

Rosa persica with a distinctive red eye is a good candidate for addition to the breeding pool of roses. In order to optimize micropropagation of R. persica، three culture media (MS، QL and VS) were compared. The maximum growth rate was observed in the VS medium. Addition of FeEDTA (Fe: 65. 4 mg/l)، calcium gluconate (Cg: 2. 7 g/l) and Gamborg vitamins (B5) instead of VS vitamins، alone or in combinationwith VS medium were compared. The maximum growth rate was obtained in the medium containing VS + Cg + B5 (VSCgB5). Various concentrations of BAP (0، 2، 4 and 8 μM) in combination with 3 μM GA3 showed that maximum growth rate was attained in the medium containing 8 μM of BAP. To reduce vitrification of Rosa persica، effects of the type of gelling agent (8 g/l agar، 4 g/l phytagel and 2 g/l agar + 3 g/l phytagel) and sucrose concentrations (30، 45 and 60 g/l) were investigated. The results showed that agar could completely eliminate vitrification and was the superior gelling agent for R. persica، whereas different sucrose concentrations did not have a significant effect on vitrification. At rooting stage، half-strength VS mineral salts and vitamins containing IBA (0، 0. 25، 0. 5، and 1 μM) and NAA (0 and 0. 5 μM) were investigated. The results showed that there was not a significant difference between different rooting media in percentage of rooting or the number of roots per plantlet.

Four advanced breeding lines of wheat which had appeared to be resistant to stripe rust in the past years along with a susceptible variety, Bolani, were intercrossed in all combinations of a half-diallel design. Seedlings were grown in greenhouse until the first leaves fully expanded and then inoculated with two pathotypes (races) 6E134A+ and 134E148A+, separately. Days to the first pustule eruption was recorded as latent period. Diallel analysis was performed by two methods of Griffing, and Jinks and Hayman. M-78-1 and M-78-10 were known as the best general combiners for longer latent period. Results of the analysis of variance of Wr+Vr and Wr-Vr, Wr/Vr regression analysis and estimates of genetic parameters indicated the importance of both additive and non-additive gene effects. Broad-sense heritability was 98% for both pathotypes. Narrow-sense heritability was 65% and 80% for 6E134A+ and 134E148A+ pathotypes, respectively.

In order to analyze variation and find an efficient selection approach، we used crossing results between two wheat cultivars، Azar2 and 87-Zhong291. F3 plants (374 lines) and four check cultivars planted in the form of augmented experiment. For germination، seeds were irrigated once. After using multiple statistics methods such as cluster analysis، 79 different lines were selected and used for RAPD analysis with UBC3 primer that hadproduced six polymorphic bands (447 fragments in total). Jaccard''s coefficient for parents was low (0. 17). Therefore، Azar-2 and 87-Zhong291 had extreme differences with each other. For the analysis of relationship between polymorphic bands and morphological characters، logistic regression was used. The majority of characters were not related to the bands but some of morphological characters، such as biological yield، plant height، main spike weight، 1000 grain weight and peduncle length showed a negative relation with some of polymorphic bands. Among them، seed number/spike trait had a positive relationship with a 600bp band. This band could be used as a selection marker for seed number/spike trait.