提高草木犀遗传转化植株再生率技术的研究

目的]确定草木犀遗传转化植株的适宜的除草荆选择压力。方法]分别以草木犀试管苗的子叶、下胚轴和破坏生长点的茎尖为外植体，在含有0、1、3、5、10mg／L除草剂草丁膦的分化培养基Ms＋BA3mg/L＋LAA0．2mg/L中对其进行分化培养，筛选适宜的除草剂选择压力，在此选择压力下，对外植体进行遗传转化，并对转化芽进行分子水平检测。结果]当除草剂浓度为3mg/L时，所有外植体均无再生芽；转化培养后，子叶、下胚轴和破环生长点的茎尖的再生率分别为0．48％、4．29％和10．1t％；分子水平检测结果显示，外源基因已成功转入草木犀转化芽中。结论]除草剂对草木犀外植体的适宜选择压力为3mg／L，破坏生长点的草木犀茎尖对外源基因的转化效率较高。

Study on Technology of Increasing Regeneration Rate of Genetic Transformation Plant of Melilotus suaveclens Leseb.

Objective] The aim was to determine the optimal selection pressure of herbicide for genetic transformation plant of Melilotus suaveclens Leseb..Method] With the cotyledon,hypocotyl and stem tip with broken growing point of M.suaveclens plantlet as the explants,they were inoculated into the differentiation mediums of MS+BA 3 mg/L +IAA 0.2 mg/L that contained 0,1,3,5,10 mg/L herbicide basta for differentiation culture,and then the optimal selection pressure of herbicide was screened out.Under the optimal herbicide selection pressure,the genetic transformation of explants was conducted and the transformation buds were detected on molecular level.Result] When the herbicide concn.was 3 mg/L, all explants had no regeneration buds.After transformation cultivation,the regeneration rates of cotyledon,hypocotyl and stem tip with broken growing point were 0.48%,4.29% and 10.8% resp.The result of molecular detection showed that exogenous gene had been transplanted into the transformation buds of M.suaveclens.Conclusion] The optimal selection pressure of herbicide on explants of M.suaveclens was 3 mg/L and the exogenous gene transformation rate of stem tips with broken growing point was higher.