Study On Opertimization System Of Virus-free Meristem In Potato

Potato is a kind of cash crop that can be used for grain, vegetables, industrial raw and so on, and have characteristics of high yield , abundant nutrition , strong adaptability , distributed widely. However the yield and quality of potato would decline with its planting in successive years. The main factor is degenerating, and one of effective measures to solve this problem is producing virus-free seed potato. Potato stem tips' tissue-cultivation is the basic of producing virus-free seeds, and high quality stem tips tissue cultivation gain time and benefit for producing virus-free plant and virus-ree potato seeds. Efficiency of virus-free potato seeds stem tips' tissue-cultivation is low currently, and the rate of burgeoning and virus-defeated cannot satisfy anticipate aim . Therefore, it is necessary that optimizing potato stem tips tissue cultivation. This experiment investigated systematically in medium of stem tips tissue cultivation and the effect of virus-defeated measurement on virus-defeated, and get main results as follows: 1. Influence of hormone to potato stem tips differentiate into plantThis experiment choose MS-medium as basic medium, in which aid plant growthed regulator of different type and different density. I get 24 combination to investigate the influence of different kinds of plant hormone as well as different density on stem tips differentiation. The result indicates that inducing stem tips differentiation not only relate to absolute density of plant hormone, but also the collocation of different kinds of plant hormone. Sprouting percentage with 0.1mg/L GA₃ is higher than 0.2mg/L when other condition is consistent, under which the result shows significant difference. These indicate that density of GA₃ have sharp impact on the stem tips sprouting of potato. The medium with 0.1mg/L GA₃ is useful for potato stem tips growing and differentiating, and at the same time 0.2mg/L GA₃ restrains the stem tips differentiation. With the same codition, the medium with 0.1mg/L NAA compares with 0.2mg/L, the later has higher sprouting percentage and reach 50%. The medium with 0.05mg/L NAA compares with 0.1mg/L, 0.05mg/L NAA is higher than in sprouting percentage and reach about 56.98%. And this treatment is also higher than the medium with 0.2mg/LIAA, which induced that 0.05 mg/L used as auxin have advanced effect on potato stem tips differentiation. Different density collocations of 6-BA and NAA have great impact on potato stem tips differentiation. Adding 0.1 mg/L 6-BA into solid-medium contain 0.05mg/L NAA is the best suitable medium to potato stem tips differentiation. At the same time, this experiment also shows that stem tips cultivated in solid medium has more and stronger sprouting than liquid medium. Liquid medium haven't the effect of callus on stem tips, and stem tips could differentiate into plant directly under the condition.2. Filtration for the medium of inducing stem tips differentiation.This experiment use 24 kinds of different medium to investigate the most optimum medium that inducing stem tips differentiation into plant. The result showed that the solid medium that have the highest sprouting percentage is MS+NAA 0.05mg/L + 6-BA 0.1 mg/L +GA3 0.1 mg/L + carrageenin 4.5g/L + table sugar 30g/L, and its sprouting percentage is 76.3%;liquid medium that have the highest sprouting percentage is MS +NAA 0.05mg/L +GA3 0.1 mg/L +table sugar 30g/L, and its sprouting percentage is 61.11 %.3. Research of virus-defeated effect of heat, stem-tips size on different varietyThis test choose ChuanYu 4, E-potato 3 and Mira as experimental material, using different heat treatment and different size of stem tips, investigated impact of different virus-defeat methods on potato virus-defeated effect. The result showed that the best virus-free effect of heat treatment is 40℃ lasted 4 hours a day and 25 ℃ lasted 20 hours a day exchange treat for 4 weeks, while the best virus-defeated effect of different size of stem tips is stem contain 1³ leaves primordium and the smaller the better in this range. The difficult-easy order of virus-eliminated is PLRVMira>ChuanYu 4, the order of percentage of these variety took two kinds of virus is E-potato 3 > ChuanYu 4 > Mira . This result shows that ChuanYu 4 is the best variety from the free-virus plant choosing, which reach 40.3%; the flowing is Mira , about 30.3%; and the fewest...