| Dandelion, a perennial herb of the Asteraceae, is a traditional medicinal plants that have a bitter tasted with sweet and cold nature and have the function of cooling and toxic material clearance, improving immunity, and nourishing the liver and gallbladder. Dandelion is very rich in nutritive material, and is considered both a Medicinal and an Edible Plant. It has become one of the most delicious foods on the table in the developed countries and regions. The purpose of this study was to induce polyploid dandelion and improve the main medicinal ingredients and major nutrients, thereby enhancing its utilizable value.The leaves from triploid tissue culture seedlings were used as explants. We established the technique system of doubling the leaves chromosome in vitro, purification and identification. Finally we obtained dandelion hexaploid plants the first time. The induced materials were compared with the six sources of dandelion in physiological indexes, content of nutrient and chemical components. Here were the mian results:1 Took leaf as explant, the best treatment was 75mg/L colchicines solution treating explant for 5 days.2 The chromosome number in the polyploid plants are 2n=3x=24, but in the hexaploid plants are 2n=6x=28 and the relative content of DNA in cell increased by 1 times. The plants showed the general characteristics of hexaploid, such as, slower growing, bigger leaf area, smaller leaf index, more leaf number, vein prominent and less stomata per unit area with larger stomata.3 The hexaploid tissue culture seedlings have a higher enzymes'activity and more resistance than the triploid tissue's culture seedlings and triploid seedlings stage of regenerated seedlings.4 The hexaploid tissue culture have high nutritional value because of the higher main nutrition content of soluble protein, soluble sugar and Vc.5 The hexaploid tissue culture have high medicinal value because it have higher content of Chlorogenic acid and Flavonoids. |
