Delivery methods for introducing endophytic bacteria into maize

摘要

The effectiveness of five methods for delivery of ten endophytic bacteria into maize stem and root tissues was studied in greenhouse conditions at Embrapa Milho Sorgo, Sete Lagoas, MG, Brazil. The delivery methods included seed inoculation, soil drench, foliar spray, pruned-root dip and seed inoculation + soil drench. The bacterial endophytes were previously isolated from maize plants, and reinoculated and recovered after treatments from maize, cv BR201. Each of the five methods led to establishment and recovery of bacterial endophytes in root tissues, but only four isolates were recovered by the seed treatment method. All 10 isolates were recovered by pruned-root dip and seed treatment + soil drench. No isolates were recovered in stem tissues by the seed treatment method, and in the root by foliar spray method. However, all isolates were recovered in stem tissue by pruned-root dip method. The pruned-root dip was the most efficient method to deliver bacterial endophytes into maize. The isolate, BR201, was recovered by almost all methods in root and stem tissues. The results demonstrate that endophytic bacteria can be recovered from maize tissues following inoculation by the different methods described, but the delivery depends on the methods used and the endophytic bacterial isolate.