Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2007 | Volume:15 | Issue:3 (29)|Papers Count:11

Seeds of alfalfa (Medicago sativa L.) were treated with various concentrations of Ethyl Methane Sulfonate (EMS) for 24 hours. The treated seeds were transferred onto 1/2 MS solid medium under aseptic condition. Germination percentage, shoot and root lengths and qualitative characteristics of the treated seedlings were evaluated. Low concentrations of EMS did not have adverse effects on seed germination. However, increase in concentration reduced the seed germination. At concentrations higher than 65mM EMS, germination as well as root and shoot growth were completely blocked. The inhibitory effect of EMS on root growth significantly was higher than on shoot growth. Seeds treated with 25 mM EMS were grown under hydroponics condition and phenotypic changes of plants were evaluated. Only one plant exhibited phenotypic changes among treated population. Although leaf color change observed in one of the treated plants, other abnormalities were not observed in the population. The effect of UV-C on germinated seeds was evaluated via irradiation of the germinated seeds with 254 nm wave length. At various doses of the UV light, however, phenotypic changes or inhibitory effects did not observe in the treated plants. In order to mutation induction in alfalfa, application of suitable concentrations of EMS gave the best results. However, irradiation of the germinated seeds with various doses of 254 nm UV beam, did not affect the germinated seeds of alfalfa.

Genetic diversity is one of the most important criteria to select parents in breeding programs. The research was carried out in order to determine genetic variability among prennial lucerne based on chemical composition, nutrition values and SDS-PAGE traits. 18 lucernce genotypes were cultivated in a randomized complete block design with two replications. Chemical composision, nutrition values and reserved proteins in seeds and leaves were electrophoresed. Based on cluster analysis of SDS-PAGE, 18 genotypes were grouped into 3 clusters Genotypes 13, 14, 15, 16, 17 and 18 in all SDS-PAGE methods were placed in same group, while genotype 12 was located in separate cluster. Principal components analysis revealed that the crud protein, P and K had the most relative variance amount.

In order to study of variation and relationships between seed yield and seed components 31 genotypes of Standard Crested wheatgrass (Agropyron desertorum Fish.ex Link) were sown in two separate experiments under optimum and drought stress conditions using randomized complete block designs with three replications in Arak, Iran, during 2004-2006. Data were collected for ear emergence date, pollination date, seed yield, forage DM yield, stem number, plant height, flag leaf size, spike length, spike number per plant, spikelet per spike, length of peduncle, seed weight and seed number per spike, thousand grain weight and harvest index. Phenotypic correlation, factor analyses and cluster analyses was conducted on data averaged over environments 14 characteristics of 31 genotypes. The results of phenotypic correlation analysis showed that seed yield had positive and significant correlation with panicle number, harvest index and spikelet per spike. DM yield had significant and positive correlation with plant height, stem number, seed weight and seed number per spike and negative correlation with ear emergence date, pollination date and harvest index. Results of factor analysis accounted for 83% of total variance for 6 first factors. The loading of factors indicate that Factor1 was strongly associated with phenological traits and DM yield. This factor was regarded as production factor. Factor 2 had significant correlation with seed yield, stem number and harvest index. The second factor was named as seed production factor. The genotypes were classified into 7 groups based on Ward clusters method. Genotypes in clusters 3, 5, 6 and 7 had higher seed production and genotypes in clusters 5 and 6 were recognized as higher values for forage production. The distribution of genotypes based on the first two factors scores were in agreement with cluster analysis.

Rosa damascena Mill. as a most important aromatic plants is the best commercial species of the fragrant roses in Iran and many countries. To study callus induction and proliferation in Rosa damascena Mill., axillary buds of five genotypes collected from different parts of Iran was used as explants. These were cultured on MS medium supplemented with growth regulator(s) and solifiled with 0.7% (w/v) agar, at 25±1oC. Different concentrations of 2,4-D (2, 3 ,4 ,5 ,6 mg/l), IBA (0.1 mg/l), NAA (5 ,10 mg/l), PCPA (3, 5 ,7 ,9 ,10 mg/l) Kinetin (0.1, 1 mg/l) and BAP (1, 2mg/l) were used. Genotypes showed significant differences (P<0.01) for callus induction, Also, highest callus induction was observed in genotypes of Kashan cultured on MS cultured medium contained 1 mg/l Kinetin and 5 mg/l PCPA. The results emphasized on genotype, kind and concentration of growth regulators as key factors in callogenensis and proliferation of Rosa damascena.

Immature and mature ovaries of Populus euphratica Oliv. were harvested from the female trees on the bank of Karun river. Five sterilization treatments were tested in a completely randomized design (CRD) with eight replications. 0.1% mercuric chloride and 70% ethanol both for 30 seconds, 70% ethanol for 30 seconds and 25% sodium hypochlorite for 10 minutes and also 70% ethanol for 1 minute and 25% sodium hypochlorite for 10 minutes were the best treatments. In order to Callus induction, four treatments were evaluated through a covariance analysis in a CRD design with six replications. MS basal medium supplemented with 3 mgl-1 IBA and 0.1 mgl-1 BAP and also 3 mgl-1 2,4-D and 0.1 mgl-1 Kin were proposed for callus induction. In addition, the regression equation between the explants age and the amount of callus production was obtained. Regression curve demonstrated the decrease of callus induction as a result of increase in explants age. Regeneration was studied using four hormonal treatments in a factorial experiment with four replications based on a completely randomized block design. MS basal medium supplemented with 2 mgl-1 BAP and 0.5 mgl-1 NAA was suggested as the best treatment. Also, combination of NAA and IBA both 0.1 mgl-1 in half MS medium was suggested as the best treatments for root production. After the different stages of acclimatization in soil, the plantlets were transferred to field.

Biological nitrogen fixation (BNF) through symbiosis is beneficial for increase of yield, reduction of production expenses, increment of soil fertility, prevention of underground water pollution. In order to study the effects of different Sinorhizobium melliloti strains on growth, and yield components of some alfalfa varieties (Medicago sativa L.) an experiment was conducted in greenhouse condition in Research Institute of Forests and Rangelands, Tehran, Iran. A factorial experiment was used on the basis of completely randomized design with 3 replications, Analyzing 3 varieties of alfalfa (Maraghehi, Hamadani and Yazdi) and 4 sinorhizobium melliloti strains (Yazd, Bosher, Rasht and Sanandaj). Varieties showed significant differences for nodule and stem numbers. Sinnorhizobium melliloti strains had significant effects on all studied attributes. Also, interaction of variety and Sinorhizobium melliloti strains significantly affected root length and number of stem nodules number.

To determine the height enhancement of Quercus brantii var. persica seedlings in the early growth stage, an experiment was performed in a randomized complete block design, with 4 replications, using eight gibberelic acid concentrations (0, 100, 300, 600, 900, 1200, 1500 and 1800 ppm). For every treatment in each replicate, 192 and totally 768 pots were used. The seedlings (from 4 to 6 leaf stages) were treated using gibberellic acid (GA3). Several parameters such as survival percentage, length and dry weight of roots and stems and number of leaves were measured five times during growth season. Results showed significant GA3 effects p<0.01 on stem length and dry weight. The highest stem length (36 cm) was observed at 1200 ppm of GA3 which was 3 times more than that of control (0 ppm). The highest root length and dry root weight were obtained at control level.