Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2008 | Volume:15 | Issue:4 (30)|Papers Count:10

There are vast endeavors by scientists to investigate gibberellin synthesis cycle in plant kingdom. One of the known genes that are supposed to be effective in gibberellin synthesis is RGL2 which was cloned in this study. Using extracted DNA from Colombia ecotype of Arabidopsis thaliana, the gene was amplified using specific primers designed based on the RGL2 gene sequence. The PET-32a(+) plasmid was selected for the gene cloning. The plasmid was digested by two specific restriction enzymes, Nco I and Sal I along with the DNA sample. Ligating the gene to the vector, an E. coli strain, XAL-Gold was used for the gene transformation. PCR conducted on the transformed bacteria confirmed the accuracy of the cloning.

Sorrel (Rumex acetosa L.) is a perennial species, being used as a model plant in molecular genetic studies of sex determination, because of several characteristics such as dioecy, sex chromosomes and short life cycle it is In this study regeneration potentials of different tissues such as cotyledon, hypocotyl, leaf, petiole and flowering stem cultured on media containing different cytokinin and auxins combinations are presented. The results showed callus induction in cultured tissues on media containing auxins. Tissues cultured on media containing cytokinins alone or in combinations with auxins showed regeneration response. The highest regeneration rate 100% was obtained from stem segments cultured on medium containing 1 mg/l TDZ. Leaf and petiole after stem had regeneration rate of 35% and 40 % on medium containing 1 mg/l TDZ and 0.75 mg/l IAA and NAA. The highest number of regenerates per explants was 8.8 using stem segments cultured on medium containing TDZ. Histological observations showed that regenerated shoots originated from the cells in the area of the vascular tissues. Regenerated shoots rooted on medium without hormone and plants produced seeds after growth in glasshouse conditions.

Medicago rigidula L. plants were collected from 3 different sites with 1450-2000m above sea level. Symbiotic Sinorhizobium bacteria were isolated from the collected plants. In addition, the symbiotic bacteria were isolated from alfalfa (Medicago sativa) as a forage crop. The isolated bacteria from M. rigidula and M. sativa L. species were identified via various biochemical characteristics, utilization of different sugars and litmus milk, tests. Responses of the bacteria to some antibiotics and different NaCl concentrations were evaluated. The in vivo experiments, including inoculation of M. rigidula seedlings with bacteria isolated from M. sativa plants, inoculation of M. sativa with bacteria isolated from M. rigidula (cross infection) as well as inoculation of M. rigidula seedlings with bacteria isolated from this species, were carried out. The results showed similarity between bacteria isolated from the annul medic and alfalfa. Furthermore, bacteria extracted from one species, can easily establish in root of the other species, and produce nodule. Based on the results obtained from various tests and experiments, the above mentioned bacteria isolated from the both species are sinorhizobium melliloti. However, number and size of the nodule produced by bacterium of one species differed from the Sinorhizobium melliloti isolated from the other species.

Ulmus carpinifolia is an important forest tree species for timber and wood production. For investigation of asexual regeneration of Ulmus carpintlolia, apical buds from old adult trees (from kojor- Mazandaran province) were gathered in 3 seasons. After surface sterilization treatments, the best method for sterilizing of buds was identified as pretreatment, cleaning and brushing of buds with tween and 70% ethanol solution, dipping in ethanol 70 % for 1 minutes and sterilizing buds with HgC12 0.3% solution in different times (5 for spring, 7 for fall and 12 minutes for winter). The suitable medium for establishment was DKW with 1mg.1-1 BA. Established explants is subcultured in 2 media (MS, DKW) supplemented with 2ip, BA (0 to 1 mg.1-1) + IBA (0.01 mg.1-1 Following 3 subcultures of buds in these media, the means of shoot proliferation and shoot length growth were used as the data for analysis of variances. The best medium for shoot regeneration was DKW with 1 mg1-1 BA, 0.01 mg.1-1 IBA (100%) Rooting of shoots occurred in DKW medium supplemented with 0.5 mg.1-1 of IBA (%90). These plantlets were transferred successfully in field

In this study, 35 Rosa damascena Mill. genotypes was evaluated based on flower yield and components, phenological and morphological characteristics. The trial was carried out in the Fadak Botanical Garden in Dezful (affiliated to Research Institute of Forest and Rangelands), Iran. The experiment was conducted, using a randomized complete block design, with three replicates during 2005-2006. Genotypes showed significant differences for flower number per plant, flower number per square meter, flower yield per plant, petal number, flower fresh weight, flower dry weight, flower diameter, plant height, canopy, leaflet area, leaflet fresh weight, leaflet dry weight and leaflet area/weight ratio (P<0.01) and flower dry matter percentage (P<0.05). According to principal components analysis, flower yield and number per plant, flower number per square meter were identified as the key selection factors and the most important traits in components. Cluster analysis resulted in genotypic classification towards 5 groups. The most genetic distances were obtained between cluster 1 and 3, cluster 3 and 4 and cluster 2 and 3. In general, genotypes showed a high variation for flower yield and components. Flower yield per plant and flower number per plant demonstrated a significant positive correlation. Therefore, they could be utilized as important evaluation criteria for selection of desired genotypes.

Red clover (Trifolium pratense) is a perennial forage legume being cultivated as a forage crop, some parts of the world. Seeds of 213 accessions conserved in Iranian red clover collection were sown in field, Karaj, Iran. Agro-morphologica1 traits were characterized according to IPGRI descriptors during 2003-2005. Coefficient of variation and Shannon index showed high levels of diversity for each trait. Erect growth habit as a desirable agronomic trait was observed in 17% of accessions. Length of main stem at flowering stage ranged from 5 to 65 cm; with a mean of 30.6 cm. Accessions from Oroomieh, Arak, Babol, Daregaz, and Sardasht with more than 50 cm stem length at flowering stage could be used as potent germplasms in breeding, for this trait. High diversity for days to flowering would provide a flexibility to reach early, moderate, and ripening cultivars. Multiple regression analysis showed a linear relationship between main stem length find plant hairiness, days to flowering, and growth habit traits. Cluster analysis classified the origin of germplasms in four groups. The origin of material with the same climate appeared together in the same cluster. Because of high levels of diversity in the first gene pool of red clover collection, this collection can play a key role in red clover breeding programs in Iran.

In this research, in vitro culture of Achillea millefolium L. was investigated with different hormones such as IAA, BA, NAA, Kin and 2,4-D. Different parts of natural plant and seedlings grown on hormone free medium were used as explants. The best medium for callogenesis was a medium supplemented with 1 mg1-1 NAA and 2 mg1-1 Kin. Apical meristem of seedling in medium supplemented with 1 mg1-1 IAA and 2 mg1-1 BA produced shoots after forming callus. Leaf explant in medium supplemented with 1 mgr: IAA and 2 mg1-1 BA and medium supplemented with 2 mg1-1 IAA and 1mg1-1 BA formed calli and then shoot. Apical meristem of seedling in medium supplemented with 1 mg1-1 BA formed shoots which produced roots upon transferring to a medium supplemented with 2 mg1-1 IBA. Thus, this medium was the best intance for propagation and regeneration than the other media.