Because of the special biological structure of bryology , it was very difficult to transfer foreign gene into the protonema or gametophyte by agrobacterium - mediated transformation . protoplasts as acceptor , using direct dna transfer methods such as microprojectile bombardment and peg - mediated transformation is becoming a good way 由于藓类植物特殊的生物学结构用农杆菌侵染其原丝体或者茎叶体很难实现转化，以原生质体作受体是藓类植物转化的常用途径。
