Temperature is one of the most effective and important environmental agents on seed germination, thus interaction effect of germination with temperature is very important in prediction of germination time and modeling especially. A completely randomized design experiment performed in seed research laboratory of Islamic Azad University, Mahabad Branch with four replications which temperature treatment were 11 levels as: 3, 5, 7, 10, 15, 20, 25, 30, 35, 40 and 45 0C. Three nonlinear regression models as Beta, 5-Parametric Beta and Segmented functions tested. Results revealed that temperature had a significant effects of rate, uniformity and germination percent. The highest uniformity and germination percentage were detected in 15 0C, but the highest value of rate of germination obtained in 20 0C. Although, there was no significant difference between practiced models in estimation of cardinal temperatures, however, the segmented model which had the less RMSE, CV and the more R2 and correlation coefficients than the others, was a better model and thus, cardinal temperatures including base, optimum and ceiling temperatures were 3. 35, 20. 84 and 40. 94 0C, respectively. Also, the maximum germination rate (rmax) was 0. 010 h-1.

To study the effect of mycorrhizal symbiosis and drought stress on MARIGOLD, a factorial experiment in a completely randomized design with three replications was conducted at the Plant Research Laboratory of Islamic Azad University, Neyshabur branch in 2014. The first factor consisted of application and non-application of mycorrhiza (Glomus intraradices) and the second factor consisted of drought stress with three levels (irrigation based on 100%, 75% and 50% of field capacity). The results showed that growth parameters like plant height, leaf number, leaf area, root, shoot dry/fresh weight, Chla and Chlb content were significantly decreased by drought stress in both mycorrhizal and non-mycorrhizal plants. However, inoculation of plants by mycorrhizal fungus increased growth parameters and photosynthetic pigments as compared with non-mycorrhizal ones. Traits like RWC, potassium and phosphorus in response to drought stress were decreased. Inoculation of plant roots with Mycorrhizal fungi increased significantly RWC, potassium and phosphorus content of the plants under drought conditions as compared with non-inoculated plants. The results also showed the mycorrhizal symbiosis by Glomus intraradices improved drought tolerance of MARIGOLD through enhancing the absorption of water and mineral ions.

In order to investigate the effect of organic fertilizers on yield and seed quality criteria of Calendula officinalisL., seeds of a field experiment under application of two levels of cattle manure (without and with 20 t ha-1) and four levels of bacterial inoculant (containing N-fixing bacteria, P solubilizerbacteria, mixture of bacteria and control) were evaluated for seed quality criteria in a factorial experiment based on completely randomized design with four replications in Medicinal Plant Laboratory of Department of Horticultural Sciences and Landscape, University of Tehran in 2010 and 2011. Then, 1000 seed weight, seed yield and dimension and seed germination quality criteria such as seed germination percentage, rate and uniformity, time to 95% germination, seedling weight and length and seed vigour index were investigated. Results indicated that interaction effect of manure and bacterial inoculant caused significantly the highest 1000 seed weight and seed yield in both years. Nearly, all criteria related to seed dimension affected by cow manure and also bacterial inoculants in both years. Also, application of cow manure significantly affected seed germination percentage, seedling length and seed vigour index (both years) and inoculation of seed by plant growth promotion bacteria showed significant effects on seed germination percentage, seedling length and seed vigour index (both years) and seed germination uniformity, time to 95% germination and seedling weight (first year). In general, using cattle manure and also plant growth promotion bacteria resulted in the highest amount of all measured criteria compared to non application of manure and bacterial inoculants.

In order to evaluate the effect of Fe and Zn foliar application in MARIGOLD (Calendula officinalis L.) on yield and essense production, the investigation was performed in complete randomized blocks design by 2 factores (Fe, Zn) with 3 replication in 2011 in shahrekord, Iran. The results showed that Fe and Zn had the significant effectiveness on many characteres contain carotenoids, flavonoids, poly phenols, length and width of leaves, height of plant, number of flowers, weight of shoot and root. Interaction effect of 2ppm Zn and Fe was the best and produced the best amounts in most of measured characters. The most amounts carotenoids, flavonoids, poly phenols was 0.3, 49.7 and 80 ppm in flower dry matter respectively. The most width of leaves (3.5 cm), number of harvested flower (Harvest 1: 4000, harvest 2: 7000, harvest 3: 6800), length of stem (30 cm), dry weight of leaf (0.35 g), dry weight of root (0.33 gr) produced by2 ppm of Fe and Zn consumption.

Colchicine is a mutagenesis chemical compound that causes many changes in plants by mutation induction. This study was conducted to evaluate the effect of application method of colchicine on epigenetic traits and reproductive phase in two yellow and orange flower genotype of pot MARIGOLD (Calendula officinalis L.). The experiment was arranged in factorial based on randomized complete block design with three replications. The first factor was two methods of seed immersion for 48 hours and spray in two true leaves stage and the second factor was different colchicine concentrations (0, 0.02, 0.04, 0.06 percentage). Flow cytometric studies showed that the colchicine affected polyploidy induction in the foliar spray. In fact, polyploidy induction was increased with increase in concentration of colchicine. The results showed that in both genotypes, lengh and diameter of flower capitol bud, flower capitol diameter, ligulate floret number, ligulate floret length and diameter of inflorescence stem were increased but tubular floret number, plant height and length of inflorescence stem were decreased (P<0.05) in plants obtained in treatment of immersing seeds in cilchicine compared with control, but the length and diameter of pollen grain and pollen- vigorous rate were not affected. Length and diameter of flower capital bud, flower capitol diameter, ligulate floret number, ligulate and pollen- vigorous rate were decreased in foliar spray treatment and tubular floret number, plant height and diameter of pollen grain were increased (P<0.05). Ligulate floret width was similar in both seed immersion and foliar spray treatments compared to the control.

With respect to the ever icreasing trend in the applicability of zeolite, superabsorbent polymer in agriculture especialy in arid and semiarid region, and vermicompost in producing healthy crop, a pot experiment was conducted in factorial based on a randomized complete block design with three replications. Treatments were zeolite at three levels (0, 3 and 6 weight percent), vermicompost at three levels (0, 3 and 6 weight percent) and hydrogel at there levels (0, 0. 2 and 0. 4 weight percent). Traits of plant height, number of leaf, flower and seed per plant, wet and dry weight of entire plant, yield of flower and grain per plant were measured. As to the result, the interatctive effect of zeolite, hydrogel, and vermicompost had a significant effect on all the tarits except number of flower, and flower yield. Most of these traits increased to increasing zeolite and vermicompost along with increasing hydrogel to 0. 2%. Interactive double effects of tratments had a significant effect on number of flower per plant and flower yield.

Plant nutrition and reduction of element deficiency is one of the most important affecting factors on plant production. Our knowledge about the effect of nutritional elements on medicinal plants is rare. In order to determining these effects, a factorial experiment as randomized complete block design conducted on research farm of university of Mohaghegh Ardabili. Treatments were four phosphorus fertilizer (P2O5) including 0, 40, 80 and 120 Kg ha-1 from the source of ammonium phosphate and four potassium fertilizer (K2O) as 0, 50, 100 and 150 Kg ha-1 from the source of potassium nitrate. Results showed that variation in growth indices trend was approximately similar in all potassium and phosphorus levels, but K2O had the major effects on the mean of growth indices. Solely P2O5 at 120 Kg ha-1 in different K2O levels had the various trend in relative growth rate in comparison to other treatments. The highest yield of grain and dry flowers was seen in the mixture of 80 and 150 Kg ha-1 P2O5 and K2O respectively, but had no significant difference with 80 and 100 Kg ha-1. In conclusion, using of K2O had more great effects on studied traits and effect of P2O5 was negligible.

In order to evaluate the effect of various levels of drought stress on some growth and bio-chemical parameters of MARIGOLD (Calendula officinalis L. ) and application of salicylic acid for mitigating drought impacts under greenhouse conditions, an experiment was conducted with a factorial arrangement based on completely randomized design with three replications at Research Greenhouse of Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman in 2015. The experimental treatments were different levels of drought stress at four levels (irrigation for fulfill of 100%, 75%, 50% and 25% of the field capacity) and foliar-application of salicylic acidat at five levels (0, 0. 5, 1, 1. 5 and 2 mM). The results showed that the irrigation levels had significant effect on all studied traits. The traits of dry weight, carotenoid contents, proline contents and soluble sugars were significantly affected by the salicylic acid treatment. Interaction of the irrigation and salicylic acid had significant effect on dry weight, proline contents and soluble sugars. The results showed that increase in drought stress caused to significant decreasing in growth parameters and also chlorophyll a and b contents. Contents of carotenoid, soluble sugars, proline and phenol were significantly increased by decreasing amount of irrigation water. Increase of salicylic acid to 1. 5 mM increased the plant dry weight, carotenoid contents and soluble sugars relative to the control conditions. 2 mM salicylic acid decreased the traits compared to non-foliar application. Generally, the results showed that application of salicylic acid specially in 1. 5 mM had a positive role in mitigation of negative effects of drought stress.

Effect of gibberellic acid on MARIGOLD (Calendula Officinalis L.) was evaluated in a pot culture experiment. A factorial experiment based on completely randomized design including 12 treatments and four replications was carried out. Main factor was foliar application stages (first, second and third) and sub factor included different concentrations of GA3 (0, 50, 150 and 250 mg L-1). Results showed that foliar application of GA3 had positive effect on photosynthetic pigments. Effect of different concentrations of GA3 on chlorophyll a was significant (p<0.01). Chlorophyll a content was enhanced by increase in GA3 concentration up to 250 mg L-1 treatment of 250 mg L-1 resulted in production of 7.78 m/g/L-1 chlorophyll a, the index which was to some extent dropped in other concentrations. Different concentrations of GA3 had significant effect on chlorophyll b (p<0.01). Chlorophyll b was increased by increase in GA3 concentration up to 250 mg L-1. the highest rate of total chlorophyll content and total pigment in three times of application and one application of 250 mg L-1 was 14.6 and 15.4 m g/L-1 respectively; whereas the lowest chlorophyll and pigment content was observed in one foliar application of control treatment with mean value as 4.67 and 5.5 m g/L-1.