| A system study of lotus shoot (Nelumbo nucifera Gaertri) tissue culture was carried out in this paper. Regeneration system was established used lotus shoot tip to explore the fittest disinfectant mode , the suitable size for explant , the perferablly fetch time , the best differentiation and the rooting medium. We studied the growth and physiological responses to temperature and photoperiod during differentiation in vitro. In the while, the activity of browning enzymes and the content of carbohydrate were studied during rhizome swelling. The results were as following:1. The establish of regeneration system in vitro: Lotus shoot tip were uses to act as explant to explore the fittest differentiation and rooting medium. Through this experiment we know that: the fittest disinfectant mode is 2%NaC1010min+ 0. l%HgCl210min; The best differentiation medium is MS medium supplemented with 6-BA1.0mg/L+NAA0.1mg/L+ 3%sucrose+0.8%agar (pH=5. 8) ;The fittest size for the explant is one buld with two leaves one outspread the other wind ;If the materials were used in April , they would turn green easy and the livability was higher than the others months. The suitable rooting medium is MS+NAA1.0mg/L+6-BA0.1mg/L +3%sucros+0. 8%agar +0. 2%AC (pH=5.8) .2.The effect of temperature and photoperiod on the growth and physiological during the differentiation of shoot tip in vitro: After 20d of differentiation pre-culture, plantlets were transplanted to the same MS medium to research the growth and antioxidant enzymes activities under different temperature and photoperiod. The results indicated that under the temperature of 25℃, the light of 14h/d, the propagate rate and the configuration index are the best. Considering from the antioxidant enzymes activities, in the former 15d, under the temperature of 20℃, the light of 12h/d the antioxidant enzymes activities are evidence hyper than the other two disposals, this shows that the seeding are under adversity. In the last 5d, under the temperature of 25℃ the light of 14h/d the antioxidant enzymes activities hoik, made the contents of MDA lower than the other two disposals, wakened the damage of the seeding. To make a summery that whether the propagate rate, the conf igurative index or the physiological index, the suitable condition is under the temperature of 25 ℃ , the light of 14h/d. The study provides reliable scientific basis for tissue culture of the lotus .3.The change of browning enzymes activities of carbohydrate content during rhizome swelling : As far as the browning enzymes the results showed that activities of peroxidase (POD) and polyphenoloxidase(PPO) increased with the swelling of rhizome and the delay in harvesting date. Marked differences in the activities of browning enzymes in different cultivars were also observed; As far as carbohydrate content results indicated : from early stage to middle stage during swelling the nutrition contents such as: starch, total soluble sugar, reducing sugar and soluble protein had a steady increase, at the end stage of rhizome swelling the nutrition had a significant increase. At the same time as the postpone of harvest the content of sucrose and total soluble sugar decrease while the content of starch increase.
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