In this res arch, a seed-drilling machine with appropriate size was designed for small farms using Auto CAD software. Then three dimensional sample of the machine was prepared by computer and its operation was simulated and recorded on videotape. When the engineering drawings were prepared, the required components were constructed and the machine was assembled according to the drawings.Preliminary workshop evaluation, using polyethylene balls with 3mm diameter, showed that there was a linear relationship between speed and the amount of seeds planted within the range of 2 to 5 kilometer per hour. With regard to mechanical damages of the balls three pieces of seed metering device (selector wheel) with different types of seed cells were constructed and mounted on the machine. The following workshop evaluation confirmed the suitability of the cell type C in which the lowest percent seed damage namely 1.24 percent and percent cell fill of about 97 at traveling speed of 3 kilometer per hour occurred. The work was followed by evaluation of the seed drill on the sand type seed bed and in the field respectively, and its performance was compared with pneumatic German made seed planter. In sand bed tests there was a significant difference between two types of planters at 1% probability level with regard to mean seed spacing, feeding quality, multiple planting, skips and planting depth indices. According to field test results carried out on two types of planting beds, there was a significant difference between two planters with regard to mean plant spacing and accuracy range of 2 indices as well as feeding quality, multiple planting, skips, percent of germination, deviation from planting line and plant leaf area and dry weight of plant indices at 1% probability level and mean planting depth and hypocotyls diameter indices at 5% probability level. Since the evaluation of the selector wheel was carried out for only one seed size of the seed, therefore further investigations are need to be made with regard to different types of ce& before different types of selector wheels according to seed size and planting spacing are recommended and constructed. To improve other indices and also to improve planting conditions of the seeds and to increase the field emergence rate for the manual planter it is suggested that further investigation of seed delivery tube as well as soil engaging components be made and after making necessary modifications, a laboratory soil bin test as well as field test be carried out for the planter.

Dodder (Cuscuta campestris Yunck) is a troublesome weed in vineyards which is hard to control. The effects of Treflan, Sonalan, Tramat and Dacthal for dodder control in vineyarsd were evaluated. Due to the hard seed coat, the dodder seeds are not able to grerminate. Treating the dodder seeds in concentrated sulfuric acid softens the seed coat so they are able to germinate. The optimum temperature for dodder seed germination and hypocotyl growth is 20-35°C. Tramat inhibited dodder seed germination while Tref1an, Sonalan and Dacthal were absorbed through epicotyl and hypocotyl and inhibited seedling emergence. The experiments conducted in the vineyards showed that Treflan at 3 Kg a. i./ha before shoveling and 1.5 Kg a. i./ha after shoveling, Sonaln 2.5 Kg a. i./ha before shoveling and 1.25 Kg a.i./ha after shoveling and Tramat 1.2 Kg a.i./ha before shoveling and 0.6 Kg a.i./ha after shoveling could control dodder in vineyards effectively. In this study the effect of Dacthal was weaker than other herbicides. All herbicides were soil incorporated after treatment.

In this investigation, the effect of crude oil on morphological aspects, development of Ovules and pollen grains and seed germination of Brassica napus L. (Brassicaceae) are studied. The plants potted under equal conditions were treated with 0.8% and 1.6% concentration of crude oil (by spraying, addition to the soil or both) at the end of vegetative phase. Upon comparison with the control groups, the treated plants showed a considerable reduction in growth, leaf chlorosis, necrosis and a total yield reduction.Exposure to 1.6% mixture of crude oil (in the use of both ways) on plants, caused a reduction in the number of pollen grains and ovules while using different concentration of crude oil results in variation of these as well as on stem anatomy. Comparing with the control groups, the percentage seed germination showed a considerable reduction while length of hypocotyl and the rate of seed germination under 1.6% concentration was more than 0.8%. In some cases, harmful effects of crude oil was not directly correlated to concentration.

Effects of culture medium containing hormonal compositions on phenotypic and chromosomal variations of sugar beet cultured tissues were examined. Experiments were carried out in different NaCl levels. Cytological studies were conducted on calli originated from suspension culture. Hypocotyl of seven day old seedlings of the two diploid lines were cultured in MS medium containing hormonal compositions to produce callus. In the next step, cell aggregates and callus fragments were incubated onto PGoB media supplemented with different salt concentrations (0-300 milimolar NaCl) and their growth was investigated. The results showed that multigerm line derived-callus had obviously more tolerance to the different NaCl concentrations than monogerm line derived-callus; so that 15 and 75 percent of monogerm and multigerm line calli grew, respectively, after being transferred from control medium to the medium containing 200 mM NaCl. Callus fragments of multigerm line had desirable growth after being transferred to the medium containing 100 mM NaCl. Also, variation was seen among callus fragments in each treatment. In another experiment, somaclonal variation was studied at chromosomal level in callus cells obtained from suspension culture in which polyploidy and aneuploidy were observed in some cells. Therefore, it is noteworthy to characterize and control somaclonal variation in cell culture of sugar beet in the desired direction for selection of salt tolerant lines.

This research was performed in order to evaluate four cultivars of cotton (Cooker312, Sahel, Saiokra, Jokuroa) for studying the percent of callus induction from hypocotyle, leaf and root segments. After production of sterile seedlings, different parts of seedlings (hypocotyle, leaf and root) were cultured on MS medium without any hormons. After production of sterile seedlings, different parts of seedlings (hypocotyle, leaf and root) were cultured on MS medium with different proportion of 2.4-0 and kin [(0.1, 0.1), (0.5, 0.5), (0.5-1), (1.1).(2.1) and (5.1) mg/lit)]. The explants incubated under light at 25±2°c for callus induction in all of cultivars, MS medium supplemented with 2.4-0 and kin (0.1, 0.1), (0.5,0.5) mg/lit containing was the best medium for callus induction in hypocotyle explants. But in media (mg/lit) 2.4-0 and kin (0.5, 0.5) mg/lit] leaf was more responsive. The most effecting medium for callus induction in root segments was MS supplemented with 2.4-0 and kin (0.5, 0.5), only in cooker cultivar and other cultivars did not response. In summary results of variance analysis showed that the factors under investigating had significant effect on callus induction, only jointed effects of variety part did not have any significant effect.

In order to determine the reaction of six sainfoin species to drought stress, an experiment was conducted in a randomized complete blocks design as factorial with four replications in 2002. Experimental treatments were included of six sainfoin species (O. viciaefolia, O. aucheri ssp. Psamophilla, O. melanotricha, O. aucheri ssp. Teheranica, O. crista-galli and 0. sojakii) and four drought levels (0, -0.3, -0.7 and -1.1 MPa), that drought levels were made by polyethylene glycol 6000 (PEG) solutions. Total weight of seedlings, germination percentage, height of radicle and hypocotyle of control and stressed seedlings were analysed. The results showed that the effect of water stress was significant on all traits. There were significant differences between species. The highest germination rate was related to 0. crista - galli species. In general, It could be concluded that O. aucherissp. psamophilla was the most sensitive species to the water stress.

Background and purpose: Digitalis nervosa is a wild species growing in Tran and the major cardenolode of this species is lanatoside A. D nervosa cell culture was estabilished and its secondary metabolites were studied.Materials and methods: Seeds of D. nervosa were surface sterilized in 70% ethanol or 5% Sodiume hypochlorite, then healthy seedlings were produced. The jemol, Hypocoty1 root tip of seedling were transferred onto the Murshige and Skoog (MS) culture media containing different concentrations of plant growth rgulators.The Phytochemical studies on callus and plant were carried out using thin layer chromatography (YLC). Total Cardiac glaycosides in plant and callus were determined by spectrophotometric method.Results: Sodium hypochlirite had less negative effect on the seedling production comparing with Ethanol.The best callus intiation and estabilishment was observed in media containing K (0.5mg/l), 2,4-D (0.5 mg/l), NAA (1 mg/l) as plant growth regulators. Callus formed from the root part of seedies revealed the presence of saponins, tannins, flavonoids, steroids and Cardiac glycosides in both callus and plant extracts. The amount of cardiac glysosides in plant was 358 mg/100 gr. Dry.W. This amount varied from 29.68 to 15.90 mg/100 gr. Dry. Wt in the 7 th Generation of callus.Conclusions: The ratio between auxin and cytokinin is one of the important factors to callus production. The 3: 1 ratio demonstrated the best callus growth on D. Nervosa cell culture. The callus culture of D. nervosa showed the ability of producing cardiac glycosides howere, this ability reduced by repeated subculturing.

Neem (Azadirachta indica A.Juss.), native to the arid regions of Indian subcontinent, is a valuable tree because its fast growing rate and many technological importanc applications. We examined micrografting of the highly interested A.indica onto Melia Azedarach L. (Persian lilac) rootstock seedling, with the objective of estimating the resistance of this union to cold treatment afterwards. In these micrografting experiments the age of rootstock, the localization of graft and hormonal treatments during the time course of growth were examined under in vitro condition and after transfering to soil. The best shoot tips graft success was found on young rootstock (40.1%) in lateral hypocotyls position. Exogenous auxine in association with cytokinine was necessary to the best union and growth. In contrast effect of treatment increased amount of 18.33%in compare to control. If salicylic acid showed an inhibitory effect on the graft-take amount of 3% in compare to control, but salicylic acid treatment cause the highest grafting success amount of 8.33% in compare to control, signifying a useful role of salicylic pretreatment in acclimatization to soil conditions for these grafted plantlets.