The Effect of Corm Weight and Soil Nutrition on Agromorphological Characteristics of Colchicum kotschyi Boiss. as a Medicinal Plant

IntroductionColchicum kotschyi Boiss is a perennial, herbaceous and medicinal plant, belong to Colchicaceae family which have corm or rarely creeping stem. Colchicum species have been considered as a medicinal plant due to having divers active components in different plant parts which have been using as drug and toxin for 2000 years ago. The most important secondary metabolic compounds in plants are alkaloids. There is much evidence that the alkaloids influence on plant growth assimilating or regulatory factor. Colchicum active ingredient is colchicine. Colchicine is an alkaloid which is found in all parts of the plant such as corms, seeds, leaves and flowers and is concerned because of the pharmacological properties (anti-inflammatory) and applications in biological studies and plant breeding (induction of polyploidy). Corm weight is an important factor for producing more active component such as Colchicine. Soil fertility management is another factor that determine the quality and quantity of plant growth. However bulbous plants compared to the other plants require more attention in terms of nutritional management, because their roots are shallow and the absorption of sedentary nutrients in the soil is more difficult. The purpose of this study was to determine the effect of corm weight and organic and chemical fertilizers on morphological characteristics of Colchicum kotschyi.
Material and MethodsIn order to evaluate the effect of corm weight and soil nutrition on morphological characteristics of Colchicum kotschyi Boiss., a field experiment was conducted as factorial layout based on a randomized complete block design with three replications at Research Station, Ferdowsi University of Mashhad, Iran, in years 2012-2013 and 2013-2014. The experimental treatments were all combination of corm weight (more than 40g and less than 40g), cow manure (0 and 50 t.ha-1), urea fertilizer (0 and 50 kg.ha-1) and superphosphate fertilizer (0 and 25 kg.ha-1). Colchicum corms in the summer which the plant is in the dormancy phase, were collected from the natural area located in the Binaloud Mountains, Frizi region Razavi Khorasan province. Because of the very much variation between collected corms in terms of their weight and in order to equalize the effect of corm weight between treatments, the mother corm was considered as one of the studied factors. Before sowing, land preparation including plowing and disk operations were conducted. The corms were sown in each plot (1×1 m) 25 cm apart at the depth of 15cm. Irrigation and weed control was done if needed. With the gradual yellowing of the leaves and when the color of capsules was changed from green to brown (late June), the plants were harvested. Data analysis and drawing graphs were done by the software SAS Ver.9.1, MS Excel Ver.11and the comparisons using LSD test was performed at the level of 5%.
Results and DiscussionThe results in both years showed that at the end of the growing season, the more weighted maternal corms produced more weighted daughter corms. Corm diameter, stem diameter, stem dry weight, leaf dry weight, leaf area, whole plant weight, leaf number and cormlet number were improved in more weighted corms (p≤0.05). Studies have shown that the early growth of the plant and its vital capacity are determined by the amount of food provided to the growing plant, by the maternal corm. Since the larger corms have more storage materials, the resulting plants are more grown and have thicker stems and larger leaves (larger aerial parts) and, in general, the dry weight of the whole plant was higher. In both years of experiment, all of the morphological characters were improved in 50 t.ha-1 cow manure treatment compared to control. Organic fertilizers improve soil structure, improve root development, regulate soil temperature and population of useful microorganisms, provide nutrients for the plant, and help to improve the absorption of nutrients by the plant. Therefore, the application of manure with all of the above-mentioned benefits improves vegetative growth and dry weight. In the second year, superphosphate increased corm diameter, leaf area and whole plant weight (p≤0.05). The interaction effects of cow manure × corm weight on leaf area and stem diameter was significant at both years (p≤0.05).
ConclusionGenerally, the results showed that Colchicum kotschyi Boiss. can respond to optimum levels of the fertilizers. Cow manure in combination with superphosphate can improve morphological characters in the field conditions.