Using Dioscorea bulbifera microtubers as material,the anatomical structure and the physiological and bio-chemical indexes of microtubers during low-temperature conservation were observed and measured,the genetic stabil-ity of germination seedlings after low-temperature conservation was also tested in this article.The results were as fol-lows:HE staining method was complicated,whose effect was difficult to observe.Compared with HE staining meth-od,safranin fast green staining was much simpler,whose effect was better.Therefore,Safranin-fast green method was more suitable for staining of D.bulbifera microtubers;Without low temperature conservation,the starch grains in the cells around D.bulbifera microtuber has not begun to be exploited and be still conserved.When D.bulbifera microtuber treated with low temperature,the starch grains in the cells surrounding microtuber began to disappear.The longer the conservation time is,the more the cell number with no starch grains also increased.The starch grains in cells had started to translate into other substances for cell life activities during low temperature stor-age.When conserving for 90 d,the cell whose starch grains disappeared extended to the middle of the microtuber;During the low temperature conservation period,the antioxidase,the amylase activity,the proline content and the sol-uble sugar content of D.bulbifera microtubers all showed an increasing trend;During the low temperature conserva-tion of D.bulbifera microtubers for 0-90 d,SOD activity during 18-54 d continued to increase,and SOD activity during 54-90 d still remained unchanged;POD activity increased significantly within 18-36 d,maintained stability within 3-54 d,increased significantly during 54-72 d,kept stable again in 72-90 d;CAT activity trends is consist-ent with the SOD activity,which continued to increase in 18-54 d,and remain unchanged in 54-90 d;α-amylase and total amylase activity increased rapidly in 18-36 d,had no significant change in 36-54 d and continuously increased significantl in 54-90 d;β-amylase activity increased significantly in 18-54 d,maintained stability within the 54-72 d,and began to increase significantly within the 72- 90 d;Soluble sugar content increased significantly within 18-36 d,had no significant change within 36-54 d,and began to increase significantly during 54-90 d;Proline content had no change in 18-36 d,increased significantly in 36-72 d,and remained unchanged in 72-90 d.There was no signif-icant difference between the seedling germinated from D.bulbifera microtubers stored at low temperature for 90 d and the seedling germinated from D.bulbifera microtubers without low temperature conservation in morphology (average plantlet length,average leaf number,average interstem length and average root number),DNA content, physiological index (total chlorophyll content,superoxidase dismutase activity,catalase activity,peroxidase activity, soluble sugar content and soluble protein content)and its leaf photosynthetic characteristics parameters (net photo-synthetic rate,stomatal conductance,intercellular CO2 concentration,transpiration rate,stomatal limitation value, water use efficiency and instantaneous carboxylation rate)and chlorophyll fluorescence parameters (initial fluores-cence,maximal fluorescence,the most photochemical efficiency of PS II,the potential photochemical efficiency of PS II,the actual photochemical efficiency of PS II,captured excitation energy efficiency of open PSII reaction center,pho-tochemical fluorescence quenching coefficient and non-photochemical fluorescence quenching coefficient),which indi-cated that low temperature conservation of D.bulbifera microtuber could not cause genetic variation of the seedling.%以黄独微型块茎为材料,对其低温保存期间的解剖结构、生理生化指标进行观察,并对其低温保存后的萌发苗进行遗传稳定性检测。结果表明：低温保存时间越长,微型块茎外围细胞内的淀粉粒消失越多,至90 d时,淀粉粒消失的细胞扩延到微型块茎中部；低温保存期间,微型块茎的抗氧化酶和淀粉酶活性及其脯氨酸和可溶性糖含量均呈显著增加趋势。在低温保存的0~90 d 内,SOD活性在18~54 d 内持续增加,而在54~90 d内基本维持不变；POD活性在18~36 d内显著增加,在36~54 d内维持稳定,而在54~72 d内又开始显著增加,72~90 d趋于稳定；CAT活性变化趋势与SOD活性一致,即在18~54 d内持续增加,而在54~90 d内基本维持不变；α-淀粉酶和总淀粉酶活性在18~36 d内快速增加,在36~54 d内无显著变化,在54~90 d内持续显著增加；β-淀粉酶活性在18~54 d内显著增加,在54~72 d内维持稳定,在72~90 d内又开始显著增加；可溶性糖含量在18~36 d内显著增加,36~54 d内无显著性变化,54~90 d又开始显著增加；脯氨酸含量在18~36 d内无变化,在36~72 d内显著提高,在72~90 d内维持不变。微型块茎低温保存90 d后,其萌发苗的形态(株高、叶片数、根数和茎节长)、DNA 含量、生理指标(总叶绿素含量、SOD活性、CAT活性、POD活性、可溶性糖含量和可溶性蛋白含量)及其叶片的光合特性参数(净光合速率、气孔导度、细胞间 CO2浓度、蒸腾速率、气孔限制值、水分利用效率和瞬时羧化速率)和叶绿素荧光参数(初始荧光、最大荧光、PSⅡ最大光化学效率、PSⅡ潜在光化学效率、PSⅡ实际光化学效率、开放的PSII反应中心捕获激发能效率、光化学荧光猝灭系数和非光化学猝灭系数),与常温保存的比较均无显著性差异,这表明黄独微型块茎的低温保存不会造成植株的遗传变异。
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