Figure 2.

The resistance (R) gene stacking method. (A) Cross-pollinated individuals, based on established trait loci, stack marker-assisted breeding and combine the combined trait loci for marker-assisted selection of the offspring. (B) A single transgene stacking event can be completed by integrating multiple genes into a single stack vector and introducing these simultaneously. (C) Targeted insertion stacking aims to insert new genes near established loci. To stack a large number of genes, this process can be repeated. The stacked genes in B and C are genetically related, such that they can be readily inserted at a single site.