Evaluation of effect of nutrient priming on the Galbanum (Ferula gummosa Boiss.) germination and seedling growth

Introduction: Galbanum is a medicinal plant belonging to apiaceae family. Gum extracted from the root has many medical and industrial applications. Because of indiscriminate exploitations from natural pastures, this valuable medicinal plant that is endangered. Gum extracted from the storage root of galbanum is the most important pastoral products of Iran that exported to European countries in high volume (Eslami Manoochehri, 1994). Many medicinal plants have low germination and growth rate because of ecological computability to environmental conditions and low germination indices in these plants have caused these plants more vulnerable to extinction than other plants (Kandari et al., 2008). Priming is one of the seed improvement techniques that enhance the germination uniformity, germination rate, seed dormancy breaking, stronger seedlings growth of primed seeds especially under stress condition and increase competitive ability against weeds. Nutrient priming is a common technique in this field that used as a beneficial seed treatment. Therefore, seeds are treated with solutions containing nutrient such as phosphorus and zinc (Asgedom et al., 2005). Improve the micronutrient in plant caused to increase the yield and seed micronutrient content (Johnson et al., 2005). This study examines the effect of nutrient priming to improve seed germination and seedling establishment in Galbanum.
Materials and Methods:This study venture out the effect of nutrient priming to reduce germination problems. The experiment was conducted in Research Laboratory of Faculty of Agriculture of Birjand University in 2010 years. For this purpose, a factorial experiment based on completely randomized design was conducted with 3 replications. The experimental factors were include three levels of prime material (Zinc Sulphate, Magnesium Sulphate and Manganese Sulphate), prime concentration at three levels (0.05, 0.1 and 0.2%) and prime duration at two levels (12 and 24 hours). Early, the seeds were disinfected by 1 percentage of sodium hypochlorite for 5 minutes. Then replaced at 4 degree centigrade for 5 weeks until seed dormancy was removed. After removing the seed dormancy, the seeds were treated with desired treatments. Then, twenty seeds from treated and control replaced in 9 centimeters diameter Petri dishes. The seeds replaced on two layer filter paper within Petri dishes. The Petri dishes were transferred to germinator with 12 degree centigrade temperature and 12 hours light cycle (light and dark). Finally, the germination indices consist of germination rate and percentage, Seed vigor, radicle and plumule length and dry weight were measured.

Results and Discussion: The results showed that the effect of nutrient priming materials on vigor, radicle length and dry weight (P> 0.01) and plumule length and dry weight (P> 0.05) was significant (Table 1). The treatment with zinc sulfate showed the most vigor. The highest radicle and plumule length was observed in the zinc and magnesium sulphate priming treatments but there was no statistically significant difference in plumule length between magnesium and zinc treatments. Seed treatment with any of the tested materials increased radicle and plumule dry weight compared to control (Table 2). Imran et al (Imran et al., 2008) reported that the nutrient priming of soybean seeds with zinc sulphate, magnesium sulphate and boric acid improves seed germination indices and increase the seed micronutrients content. Also Mirshekari (Mirshekari, 2013) reported that the Marigold seed vigor increased by seed priming with zinc and magnesium micronutrients. Effect of solution concentration on the germination percentage and rate, seed vigor, radicle length and dry weight (P> 0.01) was significant (Table 1). The results showed that all of the traits and characteristics showed the highest average at 0.05 percent concentration and with increasing concentrations to 0.1 and 0.2 percent of priming solutions, the average of all traits were decreased (Table 3). In this regard, Arif et al (2007) reported that increasing the concentration of 0.05 to 0.075 percent in zinc priming solution was reduced the chickpea emergence and biomass. Also reduce germination and seedling length affected by high concentrations of three elements boron, molybdenum and zinc in chickpea, lentil and cowpea have been reported (Johnson et al., 2005) which may be due to toxic effects of high absorbing elements (Bradford, 1995). The results showed that the increase of nutrient priming duration from 12 to 24 hours caused to improve all traits and germination indices in Galbanum (Table 4). Effect of priming duration on germination various between different species, for example increasing the priming duration lead to reduction Aquilegia Canadensis germination while increased Aquilegia caerula germination (Finnerty et al., 1992). In general, the results showed that nutrient priming with zinc sulphate 0.05 percent and 24 hours have been the better results on Galbanum germination and seedling growth.