Synthesizing Of Amphidiploid Wheats And Technology Of DNA Molecular Detection Of D Genomes

Based on the work of my research team, M71/E51 AFLP primer combinations was chosen to amplify the DNA of four amphidiploid wheats (AABBDD) and their diploid (DD)/ tetraploid (AABB) parents. A polymorphic DNA fragment of D genomes was separated, cloned and sequenced, indicating the polymorphic band of D genomes was 519bp. According to the sequence, one pair of 21bp SCAR primers (Sc-1:5'-TTAAGGACTTGTCAGCGAAGG-3' and Sc-2:5'-GAATTCCCATAGGTAGGCCGT-3') was designed with the software of Primer Premier 5.0. A single DNA fragment of D genomes with 497bp was amplified by the specific SCAR primers in eleven diploids (DD), eleven amphidiploids (AABBDD) but not in eleven tetraploids (AABB). The parr of 21bp SCAR primers could be applied to detect amphidiploid wheats (AABBDD) sourced from the crosses of diploids and tetraploids.According to infection types of nineteen diploid Aegilops tauschii (DD) and thirty-six tetraploid wheats (AABB) with five yellow rust races and four leaf rust races, susceptible diploids and resistant tetraploids were screened to synthesize the amphidiploid wheats for research of the suppressors for rust resistance on D genome. A total of twenty-seven crosses were made and fifteen triploid ABD embryos were rescued and treated with colchicines to produce functional AABBDD amphidiploid wheats. Of them, several tube culture plantlets from the crosses of Norba+Gat.194and Norba+Ae.34was successfully transplanted from tube to the flowerpots. Compared with their parents, the F1 plants of two crosses e.g. Norba+Gat.194 and Norba+Ae.34 are higher plants and better harvest, which showed hybrid vigor. The Fl plants and their parents were separately detected by the specific SCAR markers of D genomes and a 497bp unique band of D genomes could be amplified in all of Fl plants, diploid Aegilops tauschii(DD) parents and no any PCR products was obtained in their tetraploid parents (AABB), indicating the existence of D genome in the synthesizing amphidiploid wheats. The Fl plants of synthesizing amphidiploid were self-fertile. Rust resistances of their F2 population would be tested by using of different rust racesto detect the existence of suppressors on D genomes and the crosses between synthesizing amphidiploid wheats with/without suppressors for rust resisitance would be designed to study the genetic characteristics of suppressors in the future study.