减压渗透法将外源DNA导入水稻最佳时期的探讨

EXPLORATION OF THE BEST PERIOD FOR INTRODUCTION OF EXOGENOUS DNA TNTO RICE BY DECOMPRESS OSMOSIS

去壳的水稻种子，当浸渍在２５℃蒸馏水中至４、１４、３６个小时，分别转移到小麦ＤＮＡ溶液内（５００ｍｇ／ｍｌ），施以负压（－０．０６Ｍｐａ）继续浸渍４小时。在同样温度下催芽，做根尖细胞学观察和幼芽同工酶分析。并测定ＤＮＡ浸种后的减少量。结果表明：浸渍４、１４、３６小时后外源ＤＮＡ减压转导处理的水稻种子，对外源ＤＮＡ的吸收量依次降低；细胞染色体数目和形状无明显变化；居中者同工酶差异明显，苗期即出现性状变异。减压渗透法将外源ＤＮＡ导入水稻种子的最佳时期为种子吸水第二阶段的前、中期。

Rice seeds were dehulled and soaked in distilled water of 25℃ untill they started germination, The soaking period of about 50 hours could be devided into two phasses: the first was the physical phase of water absorption(about 8h) and the second was the physiological and biochemical phase of embryo germination (about 42h). Water absorbed in these two phases were 65% and 35% of the total respectively. After soaking in water for 4,14 , and 36 hours,the seeds were transferred into DAN solution(500ug/ml) of wheat for 4h with decompress(-0. 06Mpa). Then rice seeds were germination under the same tempetrature, Isoenzymes of the rice buds were compared with those of wheat. DNA decrease in the solution was also de determined and cytological observations of roots were made in seedilings of rice treated an d wheat. The results showed that the beat period for exogenous DNA introduction was the second phase of water absorption of the seeds.