微波诱变选育耐药高效溶磷苜蓿根瘤菌

Screening of Dissolve Phosphorus Rhizobium meliloti Antibiotic-Resistant Strain Using Microwave Mutagenesis

为获得高效溶磷,同时具备卡那霉素和青霉素双抗药性的根瘤菌突变株,以苜蓿根瘤菌L-5为原始菌株进行微波诱变处理,对微波诱变参数进行优化,考察突变株的遗传稳定性、溶磷量和结瘤特性。经微波(600 W,30 s)诱变,得到5株具备较高溶磷能力的双耐药突变株LW59、LW81、LW104、LW107、LW135。多次传代试验证明,LW107是稳定的高效溶磷双耐药突变株。突变株LW107具备对卡那霉素100 mg/L和青霉素300 mg/L的抗性,14 d的溶磷量达到16.67 mg/L,较原始菌株提高112.59%,固氮酶活性高于原始菌株11.7%。经植株回接试验证明,突变株结瘤能力与原始菌株无显著差异。

In order to obtain highly efficient dissolve phosphorus Rhizobiurn rneliloti strain with two antibiotic-resistant, a dissolve phosphorus rhizobium strain L-5 was irradiated by microwave. The microwave mutagenesis parameters were optimized, and the genetic stability, phosphate solubilizing power and antibiotic resistance of the mu-tant were investigated. Five highly efficient dissolve phosphorus strains with two antibiotic-resistant named LW59, LW81, LWI04, LW107 and LW135 were obtained through the microwave irradiation （600 W, 30 s）. In several passages, a mutant named LW107 with steady phosphorus solubilizing capability was obtained and it exhibits resistance to 300 mg/L ampicillin and 100 mg/L kanamycin. The phosphate solubilizing power reaching 16.67 mg/L （14 d） and nitrogenase activity are 112. 59% and 11. 7% higher than those of initial strains, respectively. Two strains of the LW107 and L-5 are inocu-lated onto the live plants and it is testified that nodulation ability of them is with no significant differences （P〉0. 05）.