Biotechnology in Apomictic Grasses

摘要

@@ Many important warm -season perennial grasses multiply by vegetative propagation, or from their seeds by an asexual mode of reproduction called apomixes. Therefore, improvement of these species through conventional breeding has been extremely difficult because of the apomictic barrier to hybridization and the impossibility to control variation in the progeny of obligate apomicts. Plant tissue culture and genetic transformation techniques has been developed as new toll of biotechnology, and which can overcome breeding barriers and introduce asexually agronomical genes into plants. Warm -season grasses are still difficult to genetically engineer, mainly due to their recalcitrance to in vitro regeneration and their resistance to Agrobacterium infection. We have established in vitro regeneration systems of embryogenic callus (Fig. 1 a -e) and protoplast (Fig. 1f) in some warm -season grasses. For genetic transformation, we made simple and inexpensive self -built particle inflow gun and established reproducible transformation system by optimizing bombardment and tissue culture conditions in bahiagrass (Fig. lg). Now, we have established transformation systems for rhodesgrass and ruzigrass. Here, we describe tissue culture and transformation systems in some warm -season grasses. In addition, we focus on describing current and future applications and impact of genetic transformation in these species.