抗除草剂转基因玉米育种筛选方法的建立

Building an Approach for Screening Transgenic Herbicide-Resistant Maize in Breeding Program

本试验建立了一个以除草剂抗性为选择标记的玉米(ZeamaysL.)转基因育种中的早期世代批量快速筛选技术。通过对玉米自交系铁7922、吉8902、丹340、PA91以及转Bar基因PA91玉米PA91TBA523在营养钵中浸灌250mg/L、500mg/L、1000mg/L、1500mg/L不同浓度的Basta除草剂的萌发试验,确立了不能正常生长的临界浓度:铁7922在250mg/L的除草剂中无法生长,吉8902在500mg/L的除草剂中无法生长;转基因材料PA91TBA523在除草剂达到1500mg/L仍与不浸灌除草剂的对照无明显差异。利用此方法对花粉管通道法转化获得的转基因T0植株的种子进行鉴定和筛选,从T0植株种子(T1)获得阳性植株6株,3株获得种子,对获得的种子(T2)再做除草剂筛选,抗性植株PCR检测均表现阳性。对以往的转基因T3做批量规模筛选,可以淘汰大量(70%)非转基因和表达不强的株系或个体,减少了田间种植工作量,提高了育种效率。

In present paper we developed a quickly batch screening technique by using the herbicide-resistant selection marker in early generation of transgenic maize （Zea mays L.）. We established the critical concentration of maize stunting growth that might be as follows, Inbreed line Tie7922 could not grow well in 250 mg/L, Ji8902 in 500 mg/L, PA91TBA523, herbicide-resistant transgenic maize in 1 500 mg/L, by the experiments of immersing seeds of the inbreed lines （Tie7922, Ji8902, Dan340, PA91） and stabile herbicide-resistant bar transgenic line （PA91TBA523） with different concentration of herbicide in earthen pots. The seeds of T0 transgenic maize plants generated by pollen tube pathway method were screened under the selection critical concentration, six plants were obtained and three of them harvested. The transgenic seedlings （T2 generations） recomfirmed positive by herbicide assay and PCR validations. It might be about 70% to distinguish low expressive transgenic lines and to eliminate the pseudo-transgenic lines in T3 generation, which used to be as transgene positive. Obviusly we have strong suggestions that this approach for screening in early growth stage should be more efficient and time-saving and also should come true by selections in the plots and plates in transgenic breeding program.