Somatic Embryogenesis And Rapid Propagation Technology Of Quercus Acutissima Carr.

Quercus acutissima Carr. is an important tree species with high economic value. In the paper,recently advances of somatic embryogenesis and rapid propagation in oak(Quercus spp.) in homeand abroad were reviewed. Based on literature analysis, new approaches of rapid propagation inQ. acutissima were explored. Somatic embryogenesis from various explants, such as seeds,mature embryos, seedling stems and leaves, mature stems, for Q. acutissima were investigated. Alarge number of somatic embryos of Q. acutissima were obtained successfully. The somaticembryogenesis technology system of Q acutissima was established. This technology systemprovided an important reference for somatic embryogenesis of different oaks. The main resultswere showed as follows:(1)The best medium to induce somatic embryos from mature embryos was MS+IBA(1.0mg L^-1)+6-BA(1.0mg L^-1)+L-glutamine(1.0g L^-1)+Proline(0.5g L^-1)on which the inductionrate could reach to70.0%. The optimal mature medium was1/2MS+IBA(0.5mg L^-1)+6-BA(2mg L^-1)+ABA(2mg L^-1)+L-glutamine(4g L^-1)+Proline(2g L^-1). The bestgermination medium was1/2MS+6-BA(0.2mg L^-1)+sorbitol(10g L^-1), and cold treatmentwas conducive to germination.(2)The best medium to induce somatic embryos from seedling stems and leaves was MS+TDZ(0.1m g L^-1)+L-glutamine(1.0g L^-1)+Proline(0.6g L^-1)+IBA(1.0mg L^-1)+6-BA(1.0m g L^-1). Mature medium was1/2MS+6-BA(2.0mg L^-1)+IBA(0.5mg L^-1)+ABA(2mg L^-1)+L-glutamine(4g L^-1)+Proline(2g L^-1)on which globular somatic embryosturned from white or yellow into green. Heart-shaped and torpedo somatic embryos have notbeen observed.(3)The best medium to induce somatic embryos from mature stems was MS+TDZ(0.1m g L^-1)+L-glutamine(1.0g L^-1)+Proline(0.6g L^-1)+IBA(0.5mg L^-1)+6-BA(2.0mg L^-1).The optimal mature medium was1/2MS+IBA(0.5mg L^-1)+6-BA(2.0mg L^-1)+ABA(2mg L^-1)+L-glutamine(4g L^-1)+Proline(2g L^-1). Somatic embryo germination has not beenobserved probably due to physiological aging of explants.(4)The somatic embryogenesis process underwent several stages, e.g. global embryo,heart-shaped embryo, torpedo-shaped embryo and cotyledon embryo. The mature somaticembryo became incompact with embryogenic callus and fall off easily. The observation showedthat somatic embryos of Q. acutissima had a apparent polarity and relative independence which were compliance with two important features of somatic embryos. So the somatic embryogenesistechnology system of Q. acutissima was established successfully in the study.(5)The best medium for proliferation of buds from seeds was MS+IBA(0.1mg L^-1)+6-BA(4.0mg L^-1). The medium MS+IBA(0.1mg L^-1)+Hydrolyzed casein(1.5g L^-1)was betterfor seedling strengthening. The best medium for bud induction from seedling stems was MS+IBA(1.0mg L^-1)+6-BA(3.0m g L^-1). The best medium for bud induction from mature stemswas MS+IBA(1.0mg L^-1)+6-BA(3.0m g L^-1).