利用原生质体融合技术选育防治植物病虫害的基因重组菌株

Studies of Breeding for Strains of Controlling Plant Pathogens and Pest by Interspecific Protoplast Fusion

本试验选用抗菌蛋白产生菌枯草芽孢杆菌ＴＧ２６和晶体蛋白产生菌苏云金芽孢杆菌ＡＳ１．９０４的营养缺陷型衍生株，在聚乙二醇的诱导下进行原生质体种间融合，获得了表现双亲遗传性状的种间融合菌株。融合率为７．５２×１０＾－６，融合子经传代１０次，稳定率为１９．５％，融合菌株的菌落和细胞形态与亲本株明显不同，通过ＳＤＳ－聚丙烯酰胺凝胶电泳检测，融合菌株表达了亲本的抗菌蛋白和毒素蛋白。抑菌杀虫试验表明。

Protoplasts of two doubly auxotrophic strains, Bacillus subtilis TG26-10 producing antifungal proteins and Bacillus thuringeinsis AS 1.904-17 producing endoto-xin proteins, were fused by polyethylene glycol treatment. Interspecific fused reco-mbinants with parental genetical characteristics were obtained. The rate of interspecific fusion was 7.52 × 10-6. The obtained fusants were subcultured on MM medium plates for a.t lean 10 transfers and 19.5% of them were stable. There were apparent differences between parental strains and fusants in colony and cell morphology.The compositions of antifungal proteins and endotoxin proteins produced by parental strains and stable fusants were compared by SDS-polyacrylamide gel electr-ophoresis. The antifungal proteins from TG26-10 strain and the endotoxin proteins from AS1.904-17 strain were observed in the fusants patterns. The results of bioa-ssay indicated that the fusants were capable of killing both plant pathogens and larvae of Pyrausta nubilalis.