Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2007 | Volume:15 | Issue:1 (27)|Papers Count:10

Optimization of callus culture of Zataria multiflora carried out in order to improve rosmarinic acid (RA) production as a secondary metabolite. The research was conducted using factorial experiments based on randomized complete design. Callus induction from the shoot node culture was realized on MS medium supplemented with 2, 4-D (0.5mg/l) and Kinetin (1mg/l). Optimized growth was obtained on Gamborg medium (salt and vitamins) with BA (0.75 mg/l) in dark. The tissues were cultivated in the same medium with sucrose (30, 60 g/1) or glucose (60, 75, 90 g/l) under 16h light/ 8h dark or continuous dark. Accumulation of RA was measured after 45 days of culture by HPLC. Accumulation of RA in callus culture was higher than in seedlings. Also, the higher biomass was obtained with callus culture. High quantities of RA (15.6%) were obtained with glucose treatment. There was not significant difference between 90 and 75g/1 glucose for RA content, but higher callus growth was obtained with 75g/l than with 90g/l glucose. The results indicated that osmotic agents and illumination had a significant effect on RA accumulation in Zataria callus cultures. Furthermore, higher biomass and RA amounts can be obtained from callus cultures than from the cultured seedling.

Genetic potential and variation of 15 Stipa arabica ecotypes collected from different regions of Iran were evaluated at Khorakian station in Qom during 2001-2003. The experiment was conducted using a randomized complete block design with three replications. Plant height, leaf, number day to germination and stem diameter were analyzed. The result of variance analysis showed that accessions are significant (p<0.05) except for node 1 and 2 interval. Correlation coefficient of plant height with other traits was positive and significant (p<0.01). Principal components analysis showed that the first three components had eigin values more than one and so entered factor analysis. Cluster analysis divided ecotypes into three groups. Ecotypes from arid region were classified in first group. Second group included several ecotypes from different regions and third group belonged to cold area.

Genetic potential and variation of 28 Haloxylon aphyllum genotypes from several arid zones of Iran were evaluated in Medicinal Plants Station in Yazd, Iran during 1998-2004. Experiment was conducted using a randomized complete block design with three replications. Plant height, canopy cover and etc. Simple and compound analysis was carried out and heritability of traits was estimated annually. Heritability of traits varied from 0.12 for branch number to 0.44 for pesil disease in 5th year. According to the results, genotypes No. 1,22,18,27 and 14 may be regarded as superior genotypes. Thus, it would be beneficial to use the genotypes with desired characteristics in next phase of this research.

This research was carried out to determine the effect of site condition on maple seedling growth and resistant traits in nursery. Seeds of 11 collection sites were planted in a nursery named Orimalek at 1550 meter altitude. The experiment was performed in completely randomized block design with three replications. Survival of seedlings after warm and cold season was recorded. Seedling height and collar diameter were measured in the end of autumn. The results showed significant differences between sites for seedling survival and height growth except for seedlings collar diameter. Seedlings from higher altitudes showed higher winter hardiness, while height growth was higher in those from lower altitudes. Winter hardiness and seedling height showed to be the most heritable traits, respectively.

This research was carried out to select the drought tolerance species according to their leaf water potential (LWP) under water stress in arid and semi-arid regions during 2004 and 2005. This study was conducted using factorial experiment based on complete randomized design with 5 replications. Farm of Natural Resources Department of IUT, Isfahan, Iran. 40, 60, 80, 100 and 120 % of potential evaporation from a class A potential evaporation pan; in 19 tree and shrub species were applied. The results showed significant differences between the plant species, the irrigation regimes two years and soil and species interaction for the LWP amount. Regression analysis between the amount of irrigation water and LWP amount showed that the increase in amount of irrigation water led to increase in LWP. Among the trees and shrubs species Quercus infectoria had the least LWP (-3.94Mp) and Salix alba had the maximum LWP amount (-2.36Mp) compared to other species. According to our studies Quercus infectoria, Olea europea, Fraxinus rotundifolia and Cersis siliquestrum species were recognized as the most drought tolerant species and Platanus orientalis, Salix alba, Populus nigra and Populus alba species showed to be the most sensitive species to drought.

Regarding the importance of control actions specially reduction of sever damage to plant from powdery mildew, natural infection rate of different Rosa damascena genotypes was studied during 2004 and 2005. This research was conducted on 40 R. damascena accessions cultivated at experimental field of Research Institute of Forest and Rangelands using a factorial experiment based on complete block design with three replications. Each sample unit consisted of 10 compound leaves collected randomly from north, south, east, west directions and center of bushes. Leaf infection percentage was calculated and registered for every accession and direction. Accessions showed significant differences (a=1 %) for infection to powdery mildew. The highest infection was recorded on Isfehan 9 accession with 67.39%, while the lowest infection was registered in Golestanl and Mazandaranl accessions with 1.63 and 1.16%, respectively. However, more investigation is necessary in order to detect higher resistant gonotypes for cultivation in areas under severe disease infection.

Salinity is an increasing problem in the world. Study of salt tolerance in medicinal plants is very important due to cultivation in saline lands. An experiment was carried out using a completely in randomized design in order to study the effect of salinity on Nigella saliva (Mashhad accession) in hydroponic condition with four replications in germination stage and with three replications in seedling stage. Salinity levels included 0 (control), 50, 100, 150 and 200 molm-3 sodium choride. The results showed significant differences for germination, vigority, root length, shoot length, root dry weight, shoot dry weight, shoot/root weight ratio, and biomass according to the increased salinity in N.saliva accession. N.saliva showed a higher tolerance to increased salinity level in seedling stage compared to germination stage.