Influences Of MS Medium Strength And Calcium Concentration On The Growth Of In Vitro Virus-free Potato Plantlets And Microtuber

The composition and concentration of nutrients in culture medium is an important factor to affect plant growth. Different kinds of plants in plant tissue culture require different concentrations of essential nutrients, and the different varieties of the same species have different requirements on the concentration of essential nutrients. The production of Potato Virus-free propagation and Microtuber is an important link of potato breeding. Seedling cultivation and increasing microtuber yield has been concerned by the agricultural technician. The purpose of this study was to study the effect of different MS medium strength and calcium concentration on the test tube seedling and mini potato. The experiments were performed on Two Potato Clones（T13-26-1 and T11-197-1） with different growth characteristics on standard MS medium. These two clones were selected from the hybrid combinations of Holland germplasm resources. MS medium was setted with 3 levels（1 / 2 MS medium, MS culture medium, 3/2 MS medium）, and concentration of C a Cl2 had 5（3, 6, 9, 12, 15 mmol/L） levels.A second factor completely randomized design was adopted,repeating 3 times. The main results are as follows:（1）The test tube seedlings of two clones（T13-26-1 and T11-197-1） were tall, the number of nodes, the length of the stem, the fresh weight of the stem and the dry weight, the stem diameter of the MS strength and the reaction of the calcium ion concentration. These traits were not significant in different Ca treatments, and the interaction effect of MS intensi ty and calcium concentration was not significant. Under the lower MS intensity（1/2 MS）, the two cultivars were the highest and most of the length of the length. Under the lower MS intensity（1/2 MS） and standard MS, the maximum number of nodes and the fresh weight of stem and leaf were the highest. For stem leaf dry weight, T13-26-1 are the best performance in MS 1/2 and standard MS, and T11-197-1 did not find significant differences in different culture medium strength. For stem diameter, the stem diameter was the most thick in the standard concentration MS medium（1 MS）.（2） The two tested clones（T13-26-1 and T11-197-1）’s response to MS strength,and calcium ion concentration is not the same in root length, root number, root dry weight, root two measur ed clones. For root length, T13-26-1 in low concentration of MS culture medium（1/2 MS） and 9 mmol / L CaCl₂ root length, and T11-197-1 in standard MS culture medium（1 MS） on root length and calcium treatment had no significant difference. The root number of T13-26-1 was not significantly different between the strength and the calcium concentration of MS, while T11-197-1 was most in the high concentration medium（3/2 MS）. T13-26-1 in the standard concentration of MS medium（1 MS） on the root fresh weight of the most weight, calcium treatment is not significant. T11-197-1 in the standard medium concentration of MS（1 MS） and calcium concentration of 9 mmol/L CaCl₂ on root fresh weight. T13-26-1 root stem focusing on MS culture medium intensity and the concentration of calcium had no significant difference, and T11-197-1 concentrations in the standard MS culture medium（1 MS）, and the concentration of calcium was 9 mmol / L CaCl₂ on the of root dry weight of the most important.（3）The chlorophyll content of the two tested clones（T13-26-1 and T11-197-1） was consistent with the response to the MS intensity and the calcium ion concentration. MS intensity difference was very significant or significant, calcium treatment was not significant. At high concentration MS medium（3/2 MS） was beneficial to the formation of chlorophyll. For the index of MDA, from the point of view of treatment combinations, two potato strain response are basically the same, namely in the high concentration of MS culture medium（3/2 MS） and 12 mmol / L CaCl₂ treatment combinations, malondialdehyde content was most., meaning that high strength MS heightening calcium treatment may have a toxic effect on plantlets.（4）The reaction to intensity of MS of total yield of two tested clones（T13-26-1 and T11-197-1） tubes was different.In high concentration of MS culture（3/2 MS） and high 12 and 15 mmol/L)calcium concentration,T13-26-1 microtubers’ stotal weight was the highest, and T11-197-1 is concentrations in the standard MS culture medium（1 MS）, total weight of microtubers most, calcium treatment difference not significant.The responses of the two potato lines were also different in the total number of potato tuber.From the main effect, the difference of the number of the T13-26-1MS medium intensity was not significant, while T11-197-1 was the highest in the high strength MS medium（3/2MS）.For T13-26-1, 6 mmol/L calcium is beneficial to the sweet potato, but more than 9 mmol/L（including 9 mmol/L） decreased the number of nodes.T11-197-1 showed no significant difference in calcium treatment.For the weight of the tuber（diameter greater than or equal to 5 mm）, two clones of culture medium main effect of reaction, with the standard MS culture medium（1 MS） best, also similar to the reaction of calcium concentration, high concentrations of calcium have conducive to the increase in test tube potato tuber weight.In short, high concentration of MS culture medium（3/2MS） is not good to plant height, number of knobble, fresh weight and dry weight of stem lea f, growth of stem diameter,and the best concentration of MS to get higher breeding ratio is 1 / 2 MS; the reaction of different clones in vitro seedling root system to culture medium and calcium treatment is more complex. High concentration MS medium（1MS or 3/2MS） enhances total production of microtuber, while high levels of calcium（12 and 15 mmol/L） only increses the T13-26-1 microtuber production. The high concentration medium（3/2MS） can promote the generation of T11-197-1vitro potato, and the higher level of calcium（6 mmol/L） is helpful to increase the number of T13-26-1 in vitro potato.The results of the study has a guiding significanceon how to improve the quality of test tube seedlings and the number of test tube.