Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2014 | Volume:22 | Issue:1 |Papers Count:18

One of the important perennial herb in Apiaceae family is Black caraway (Bunium persicum) which is growing naturally in some regions of Iran and a few neighboring countries. In order to evaluate genetic diversity of Iranian germplasm, nine ecotypes of the species were collected and their ITS2 and ITS1-5.8s rRNA- ITS2 regions were amplified by PCR and sequenced.Sequences were aligned in the ClustalW method by using MegAlign program. Phylogenic dendrogram, identity and divergence matrices were designed. Low genetic diversity was found among the ecotypes in comparison with previous studies via morphological and biochemical markers. Comparison of the sequences of ITS1-5.8s rRNA- ITS2 regions of two ecotypes (Mashhad University and Kalat Naderi) with ref-seq genomic database at NCBI, showed the highest similarity withSorghum bicolor, Oryza sativa, Arabidopsis thaliana and Vitis vinifera sequences. Considering low similarity between the results of two distinct studies of the authors, results of morphological and biochemical markers are more reliable than molecular markers (ITS2). It could be concluded that the ITS2 molecular marker does not seem to be compatible for intra-species studies. Other convenient molecular markers for assessment of genetic diversity of black caraway are suggested.

Medicinal plants are rich sources of natural products used for production of pharmaceutical products. Thymus genus belongs to the Lamiaceae family which has more than18 different species distributed in different areas of Iran. Pharmacological effects of thyme are related to phenolic monoterpenes such as carvacrol and thymol. Despite pharmacological effects, the phenolic compounds and other secondary metabolites are major problem for isolation of high quality RNA in gene expression analysis and genetic engineering. In the present study, seven different isolation protocols were compared to extract total RNA from three Thyme species rich in phenolic secondary metabolites in terms of quality and quantity of RNA samples with respect to spectrophotometric reading, denaturing agarose gel electrophoresis, Reverse Transcription Polymerase Chain (RT-PCR) and Real Time-PCR reactions. Three methods of isolation together with two commercial buffers and two kits that were commercially available were used.Results indicated that RNA isolated bymodified SDS- phenol protocol was goodquality and quantity, where standard RNA isolation methods involving GeneJET Plant RNA Purification Mini Kit and TRIZol extraction buffers failed. Finally, we proposed a new suitable protocol for isolating RNA from Thyme leaves rich in secondary metabolites.

Sumac belongs to genus of Rhus (Anacardiaceae). Seed germination in the species is very low and it is naturally propagated through tillering. The best media forIn vitro regeneration and rooting of sumac was investigated in this research. Buds were sterilized and transferred to callus induction media. Callus induction was initiated on MS basal media supplemented with IAA, BA, BAP, TDZ, IBA. Results indicated that the most callus induction and regeneration occured on MS supplemented with 1 mgl-1 BA+0.5 mgl-1 IAA. Half, quarter and full strength MS medium supplemented with IAA, NAA, IBA were used for rooting. Results showed significant differences between the rooting treatments. The most rooting percentage was observed on full strength MS medium supplemented with 1 mg/l IBA. The best treatment for rooting was 1 mg/l BA+0.5 mg/l IAA. There were significant differences between IBA concentration for length and number of root. With 5 mg/l IBA concentration, number of root increased and root length decreased. Also, there were significant differences between liquid and solid media for rooting, so that the highest rooting percentage (44.83%) was observed on solid media.

Amygdalus scoparia L. is an important medicinal and commercial species of Rosaceae, resistant to heat and drought. Iran's weather is dry, thenA. scoparia is suitable for reforestation in the country. A.scopariaproduces bitter seeds normally but one sweet Amygdalus stand was found among the bitter Amygdalusaccessions in Naein province. Due to economical importance of Amygdalus sweet seeds and for preservation of genetic resources in natural stands, this research compared the morphological, biochemical and variation of the sweet and bitter accessions. Morphological characters such as leaf length and width shoot and petiole length, seed and kernel weight were compared. Biochemical analysis of seed extracts, in comparison with standard sample, determined their amygdaline quantities.Protein profiles of seed storage extracts were compared using SDS-PAGE techniques. Results revealed that means of shoot length, leaf length and width, seed diameter and kernel weight for sweet genotype were less than those of bitter ones, but petiole length of sweet stand was longer than that of bitter. Leaf width in sweet stand was the same as that of bitter ones. Quantity of amygdaline in sweet sample was less than that of bitter ones. Due to differences observed between the protein profiles on the genotypes, this method seems to be suitable for genetic variation evaluation ofA.scoparia population.

Thirteen ecotypes of Medicago truncatula from Iran and Australia were evaluated for salt tolerance under normal and stress conditions using a factorial experiment. In both of the conditions a high amount of diversity was observed. Results of correlation analysis showed that leaf number is one of the most important traits for increasing forage yield. Moreover, correlation between plant height and K or Na concentration was significant and negative. According to principal components analysis, the first three principal components with eigen values of more than 1 contributed 73.7% of the variability amongst the ecotypes. PC1 positively correlated to leaf number, tillage number and shoot fresh and dry weights. Characters with the biggest values on PC2 were root fresh weight, root dry weight and K concentration. Whereas, PC3 was positively correlated to plant height and Na concentration. The ecotypes were grouped into two main clusters using cluster analysis. In the first cluster, tolerance and in the second cluster susceptible ecotypes were observed. The results could be used for germplasm management and also in breeding programs.

For evaluation of some physiological characteristics in several populations ofAegilops triuncialisunder drought stress, a factorial experiment was conducted based on completely randomized design with three replications at Mohaghegh Ardabili University during 2011 under greenhouse conditions. Three moisture regimes as levels of the first factor were full irrigation, irrigation until booting stage and irrigation until 50% heading, and 8 different populations of A.triuncialisconsidered as levels of the second factor. Components of chlorophyll fluorescence (FM, FV/FM) and number of stomata decreased with increasing severity of drought stress. There was a marked decrease in leaf chlorophyll and carotenoid content under drought stress condition particularly at booting stage. Drought stress also reduced 26% of leaf relative water content at both levels of stresses, as compared with non-stress conditions. Stomatal conductance decreased 46% and 55% in drought stress at booting and heading stages, respectively, but proline content increased. Under drought stress at heading stage, Hurand, Maku and Marand populations in terms of leaf relative water content were relatively superior to other populations and these populations could be considered as drought tolerant populations for future research.

To study karyological and relationship between 16 populations of genusAgropyron, namelyAgropyron deserterum, A. tauri, A. repens, A. pectiniforme, and A. imbricatum (3 populations for each species, except forA. imbricatum), root meristem cells were used. Four suitable metaphase plates for each population were selected and photographed. Results showed, the basic chromosome number in all of the populations was x=7 and ploidy levels were 2x, 4x, and 6x. Results of analysis of variance revealed significant differences between the populations based on all karyotypic characteristics (P<%1) except for total form percentage (P<%5). This indicated occurrences of quantitative changes in chromosome size of the studied populations. Average size of the chromosome in the studied populations was 10.518 micrometer. Using principal components analysis (PCA), the first three independent components accounted about %93.96 of total variation. The first component indicated that length of total chromosome, length of long arm, arm ratio, centromeric index, total form percentage, and intra chromosomal asymmetry index were important characters for classification of the populations with about 57% of total variation. By cutting dendrogram resulted from cluster analysis (Ward) in metric distance 2.584, the populations were classified into 5 groups. The lowest metric distance was obtained between two populations, A. deserterum(15357), and A. imbricatum (11389) and the highest metric distance was obtained betweenA.deserterum (629) and A.taur (327), that indicates the least affinitybetween them. By a diagram of the genotypes dispersion, based on the two first components, the populations were grouped into 5 separated classes, which agreed to the results of cluster analysis.

Eighteen inter-simple sequence repeats (ISSR) and 10 inter-retrotransposal amplified polymorphism (IRAP) markers were applied to investigate the genetic diversity of 150 natural gall oak (Quercus infectoria) and 109 Lebanon oak (Q. libani) individuals in North-Zagros forests. Among the Q. infectoria populations, ISSR and IRAP primers amplified 202 and 136 bands, respectively, of which 194 and 135 bands were polymorphic. While, the primers amplified 178 and 134 polymorphic bands from a total of 187 and 137 amplicones in Q. libani genotypes, respectively. High level of genetic diversity at the specific level was revealed in both species. Analysis of molecular variance shawed that a major proportion of total genetic diversity belonged to within populations. In both species, the Nie’s gene diversity index (h) was higher for ISSR than IRAP primers. No significant genetic relationship was detected among genetic distance of the populations and their geographical distribution, demonstrating the genetic relationships among isolated Q. infectoria and Q. libani populations via gene flow. Cluster analysis grouped the populations of both species into distinct groups, showing efficiency of studied markers to assessment of genetic polymorphism of oaks natural populations.

Eucalyptus salignawith several characteristics such as medicinal and industrial uses and fast growing feature could be considered as an appropriate case to be used in countries with low forest covers such as Iran. Although reforestation byEucalyptus species is very important, but production difficulties by conventional methods, causedin vitro culture methods to be considerable. Somatic embryogenesis is an effective tool for reforestation with improved tree species. The method is more economical than other cloning methods. Somatic embryogenesis onE. saligna was studied in this work, for the first time. Four kinds of explants, root, stems, leaves and hypocotyls of seedlings, were grown atin vitro conditions on MS medium with 13 hormone treatments. The best explants was root and the best hormone treatment was 2 mg/l kinetin with 2 mg/l 2, 4-D. In general, the somatic embryogenesis results of this study were more effective than previous studies on Eucalyptus species. The embryogenic calluses were transferred to three MS mediums supplemented with different ABA concentrations to reach to maturation. Treatment with 20 mg/l ABA showed three stages of globular, heart shape and torpedo.

Festuca arundinaceahave tolerant to various climatic conditions. It could have good roles in forage production for livestock feeding and soil conservation. To investigate the relationship between morphological traits and yield, 36 accessions ofFestuca arundinacea were sown based on randomized complete block design with three replications under dryland farming system conditions, during 2008 and 2009. Plant length, internodes length, flag leaf length, number of stems per m2, days to pollination as independent variables and forage yield as the dependent variable were recorded. Based on regression analysis, forage yield had significant linear relationship with the independent variables. Independent variables showed a significant positive correlation with forage yield. Days to pollination showed no significant correlation with other traits, but the other traits showed pair wise correlation significant positive correlation. Path analysis results showed that the trait of plant height had the greatest direct effect (0.468) and indirect positive effect by stems per m2 and flag leaf length on forage yield. Days to pollination had high direct effect (0.251) on the forage yield. In addition, selection based on all traits specially plant height and days to pollination can be useful to increase forage yield.

The research was performed on reduction of seed germination capability of seven forest tree species which had been stored in natural resources gene bank, Iran.Rhus coriaria, Smirnovia turkestanaand Seidlitzia rosmarinus (2 accessions) were stored for 10 years whereas, Pinus pinea, P. pinaster, P. radiata(2 accessions) and Prosopis stephaniana were stored for 22 years at 5oC. Two separate experiments were carried out based on the storage periods. A completely randomized design with three replications was used for each experiment. Results showed that there were significant differences between the accessions for reduction of germination.Regarding the accessions stored for 10 years, Seidlitzia rosmarinus (from 69 to 63%), Rhus coriariaand Smirnovia turkestana (from 95 to 18.3%) had the lowest and highest reduction in germination, respectively. Seed origin effect was significant onSeidlitzia rosmarinus in such a way that the seeds collected from Khuzestan had more reduction in germination than seeds collected from Yazd. Based on the second experiment, Pinus pinea with Turkey origin and P.radiatacollected from North Khorasan province, Iran, had the highest (from 71 to 11.6%) and the lowest (from 82.6 to 52.6%) germination reduction, respectively. Although the studied seeds are orthodox, but there are considerable differences among them regarding to seed deterioration.It is suggested that conservation program of the plant genetic resources via seed needs a flexible management with regard to the effects of species and their origin.

Knowledge of the pollination system and the amount of self-Incompatibility is the first step for choosing appropriate breeding method. This study was conducted to investigate the amount of self- incompatibility and selfing in 25 genotypes of cocksfootDactylis glomerata, a perennial forage grass, under two moisture environments (non-stress and drought stress) based on a randomized complete block design. Half of the panicles of each genotype were bagged for obligate selfing and the rest were allowed to open pollinate. The results showed that under non stress conditions the average number of seeds per panicle for open pollination was 31.3 and for selfing was 4.2. Under drought stress conditions, these values were 21.16 and 2.0, respectively, indicating that the effect of relative environmental conditions (drought stress) on seed production in terms of both selfing and crossing. The same trend was also observed for seed weight. Under non-stress conditions variation among genotypes for seed weight per panicle was more than stress conditions. High variability was observed among the genotypes for selfcompatibility index and for this regards the genotypes with the highest and lowest incompatibility rate were determined. The results also showed that the production of the inbred lines in cocksfoot is possible in order to develop new improved varities.

To study genetic diversity of alfalfa germplasm and traits affecting yield forage, 30 populations alfalfa were assessed in research field of Bu-Ali Sina University, Hamadan, Iran during 2012. Cluster analysis was used based on all of the recorded characters, using Ward method, by which the populations were grouped into three clusters, and the maximum genetic distance was obtained between populations Zabo15 and Karaj 2122 that could be used to create optimistic hybrids. Minimum distance related to the cluster center of the second and third clusters. Factor analysis with varimax rotation was performed for ten traits and reduced them down to three common factors which were accounted for 70.65 of total variation among the populations. The first three factors were named as forage yield, resistance to the weevil and plant height.

Fifty six populations of sainfion (Onobrychis viciaefolia) were evaluated for responses to powdery mildew using randomized complete block design at Alborz research station, Iran, during two years. Results showed different degrees of disease severity index among the studied populations. During, 2008, Several populations such as Polycross-Karaj, Oshnaviah, 9262 (Karaj), 8199 (Tehran), 2399 (Karaj), Tehran (3001), Karaj (15353), North-Khorasan (3062), and Chaharmohal (8799) had disease severity index, lower than 25% which were regarded as tolerant to powdery mildew. The disease severity index of several populations such as Ardebil (20520), Karaj (9054), Ahar (20521), Bonab (20357), and Tabriz (2958), were in range between 25-50%, regarded as semi-susceptible. The rest of the populations with disease severity index more than 50%, nominated as susceptible. The evaluations were continued on selected populations for both disease and forage yield during 2009. There was significant differences between the populations for both of the traits for three successive cuttings. Forage yield of Tehran (3001) and Chaharmahal (8799) was higher than means of semi-susceptible and susceptible populations. Results implied that the last two mentioned populations and Oshnaviah could be considered as desired parents for developing synthetic varieties of the species.