双抗性标记花生内生菌的诱变与筛选

SCREENING AMPICILLIN AND KANAMYCIN-RESISTANT STRAINS FROM PEANUT ENDOPHYTE MUTANTS INDUCED WITH ULTRO-VIOLET

以花生内生菌１号为出发菌株，应用紫外线对其进行诱变处理，从中筛选氨苄青霉素和卡那霉素双抗标记菌株。结果表明：第一，３０Ｗ紫外灯、距离４５ｃｍ、菌体浓度为１０６ｃｆｕ／ｍｌ以上、照射时间１ｍｉｎ的诱变处理效果最好，可以获得大量与原始菌株培养性状及生物学性状相同，且稳定的抗氨苄青霉素和卡那霉素的突变菌株。第二，双抗标记菌株的筛选方法以二步诱变筛选方法的诱变效果优于一步诱变筛选法，其双抗菌株的诱变频率可以提高１．５倍，且抗性十分稳定。第三，双抗标记菌株的抗药性可以逐步诱导提高，在含８０μｇ／ｍｌ氨苄青霉素和５０μｇ／ｍｌ卡那霉素培养基上仍能正常生长。

? Many stable double-marked (ampicillin and kanamycin-resistant marks) peanut endophyte strains were screened from the mutants of endophyte strain 1 through ultra-violet treatment.The results showed that: First,the mutation effect is the best when the endophyte strain 1,which cell concentration is more than 106 cfu/ml,was irradiated for 1 minute with ultra-violet lamp (power 30w) under 45cm;Second,compared with one-step screening method, the mutation effect of two-step screening method is better,the double-marked mutation frequency was increased by 150%.However,the ampicillin and kanamycin-resistance of double-marked strains were very stable;Third,double-marked strains can be gradually induced to raise its resistance of ampicillin and kanamycin, because they can grow on the medium containing 80μg/ml ampicillin and 50μg/ml kanamycin.