Establishment Of Plant Regeneration System And RolB-pttGA20ox Genes Transformation Of Populus Euphratica

The major objective of this study was to breed new Populus euphratica varieties with improved rooting ability and apical dominance through transformation of the rolB-pttGA20ox two genes by using Agrobacterium tumefaciens-mediate transformation technology. For this purpose, first, an efficient in vitro propagation system and plant regeneration system were developed for Populus euphratica. Factors that affecting shoots regeneration via plant growth regulators etc., were investigated in details. Subsequently, parameters that affecting the efficiency of Agrobacterium tumefaciens-mediate transformation of Populus euphratica were comprehensively studied and optimized by accessing NPTâ…¡expression, and a transformation protocol was established. Finally, on the basis of the established transformation system, pttGA20ox,rolB-pttGA20ox genes were transferred to Populus euphratica by PCR and PCR-Southern blotting tests.The results of this study were introduced separately as following:1. Establishment of plant egeneration system of Populus euphraticaThe optimum sterilized measure for summer material is to be immerged in 70% ethanol for 30seconds and then in 0.1% HgCl2 for 7 and 8 minutes in succession. For stem apexes, it's better to be immerged in 70% ethanol for 30seconds and then in 0.1% HgCl2 for 0.5 minutes, but for stem segments with axillary buds the optimum time in 0.1% HgCl2 is 1.0 minutes. The optimal induction medium was MS+6-BA0.5mg/L+NAA0.1mg/L, the proliferation medium was MS+6-BA1.0mg/L+NAA0.2mg/L+sugar20g/L, and the most optimal rooting medium was 1/2MS+IBA1.0mg/L+surar 25g/L+AC0.2g/L, rooting rate being up to 81%. And the appropariate substance for seeding transplantation is vermiculite and perlite in 2:1 or sand and soil in 1:1.2. Etiolation in the vitro of Populus euphratica.and measures:The etiolated rate was increased with the increasing of days obviously within a subculture circle. With some index of physio-biochemical the results showed that: when the subculture time was more than 20 days, chlorophyll content falled much especially...