“…To avoid these problems, supports made of polyester, ceramic or wood pulp fiber have been substituted for agar and found to be superior (Cheng and Voqui, 1977;Doi et al, 1992;Nagaoka et al, 1987;Nishimura, 1988;Oishi and Sasaki, 1989). These supports are porous, spongy materials, so that explants or plantlets can be cultured on a liquid medium.…”