Abdolreza Ramezan Ghanbari; Iman Rohollahi
Abstract
Introduction: The genus Muscari has 47 species according to the World Checklist of Selected Plant Families. M. armeniacum, belonging to the family Asparagaceae, is cultivated in pots and gardens in the temperate regions. Muscari armeniacum is commonly known as grape hyacinth owing to its clusters of ...
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Introduction: The genus Muscari has 47 species according to the World Checklist of Selected Plant Families. M. armeniacum, belonging to the family Asparagaceae, is cultivated in pots and gardens in the temperate regions. Muscari armeniacum is commonly known as grape hyacinth owing to its clusters of small, bell-shaped, cobalt-blue flowers that look like clusters of upside-down grapes. Traditional methods of propagation of Muscari species are rather slow, since the bulblet production from the mother bulbs is extremely low. Muscari as a cold resistance, bulbous flower with blue color and tendency to flowering many times can be used in many prospects. On the other hand, the color of M. neglectum is precious as natural pigment, and it has many beneficial and useful compounds that may support human health. Traditionally, scoring facilitated the in vitro and ex-situ propagation of bulbous flower. The manipulation of ploidy is a valuable tool in improving crops. Out of many applicable methods, the use of chemicals to induce changes in chromosome number has been well established. Colchicine has been successfully applied to induce polyploidy in a series of crop species. The chromosome reduplication of Muscari armeniacum can be induced with mixed and soaked colchicine.
Material and Methods: Mature bulbs of Muscari armeniacum were bought online (www.flowerbulbsholland.com). After treatments in first and second experiment, bulbs were cultivated in experiment garden. Polyploidy induction and viability percentage by colchicine and scoring in Muscari were evaluated separately in tow factorial experiment based on the completely randomized design with three replications for two years. In the first experiment colchicine, 0.05% by 12, 24 and 32 hours of soaking time under scoring (with scoring and without scoring) treatment were evaluated. Finally, morphological traits such as raceme length, leaf length, leaf number, leaf width, and peduncle length were evaluated and in second year morphological traits, as well as microscopic traits including stomata numbers, stomata densities, stomata length and width were evaluated. In the second experiment, colchicine 0.05 and 0.1% with 24 h soaking time and scoring (with scoring and without scoring) treatment in three replications were examined according to the first experiment details. Five well expanded leaves of each plant were selected to measurement and scoring the size and density of stomata. Three samples of epidermal cells were obtained from lower surface by nail varnish technique. A small area of abaxial side of leaves was covered with thin layer of clear nail polish and left to dry. After drying the polish, it was removed with a tip forceps then placed on a glass slide and observed through the light microscope at 400 x magnification and studided bu=y digital image processing and analysis. Stomatal density, length and width were measured for each image. Stomatal elongation was counted as the ratio of stomatal length and stomatal width.
Results and Discussion: Results of the first experiment showed the heights viability (100%) and flowering (55%) in non-scoring bulbs and 12 hours colchicine treatments. Also the lowest viability (55%) and flowering displayed in 32 hours colchicine and scoring treatments. At the second year of first experiment the highest viability percentage (75%) and flowering (10%) indicated in non-scoring bulbs and 32 hours colchicine treatment. The lowest viability (30%) and flowering (0%) percentage showed in 12 hours colchicine treatment with scoring bulbs. At the second year of first experiment 12 hours colchicine 0.05% significantly increased leaf width (0.63) and stomata width (0.015). Based on our results in the first experiment, in second experiment only 24 hours colchicine 0.1% treatment was evaluated. At the second year of second experiment colchicine and scoring interaction treatments had significant effects on stomata numbers. Bulbs that were scored and treated with colchicine 0.1% didn’t germinate and colchicine 0.05% decreased stomata density significantly compared to control.
Conclusions: The results of the experiment showed that colchicine 0.05% in 12 h of soaking time is one of the best treatment for Muscari polyploidy induction. Whereas, 32 h colchicine 0.05% treatment showed the highest flower percentage and viability in second year. Also, scoring and colchicine 0.1% had a negative effect on the viability and the flowering percentage. High colchicine concentration and scoring treatment decrease viability and flowering. Finally, colchicine 0.05% for 24 h without scoring could increase the possibility to induce ploidy.
