Abstract:

Ta1 wheat C₄ recurrent selection population with improved quality characters were detected by specific PCR marker of 1Dx5 subunit, and retested by SDS-PAGE technique. The objectives of this study were is to study the genotype composition of 1Dx5 subunit and the feasibility of its specific PCR marker used in recurrent selection，furthermore，to provide the scientific evidence of molecule marker assisted recurrent selection breeding of Ta1 wheat. The results indicated that：（1）450 bp special fragment was amplified using 1Dx5 specific PCR technique in all the plants with 1Dx5 subunit，and the result of biochemical marker indicated that all the plants with 450 bp special fragment also had 1Dx5 belt，the results of molecular marker and biochemical marker were the same. And the high repeatability of PCR amplification indicated that specific PCR marker had high accuracy on selection，which were suitable for detecting genotype of 1Dx5 in Ta1 wheat improving population(Fig.2 and Fig.3). （2）The percentage of high quality genotype of 1Dx5 in the C₄ recurrent selection population was high，which was 56.81%，and almost associated with 1Dy10. The result of biochemical detection showed that the rare subunits of 5+12 and the polymer of 14+15 and 5+10 were also found in the population(Fig.5). (3) Stability of specific PCR marker of 1Dx5 subunit was high，duplications of the same sample were with no exception, 450 bp special fragment was produced in all of them (Fig.4)，so the availability of molecule marker assistant recurrent selection of Tal wheat which can improve the composition of high molecular weight-glutenin subunits(HMW-GS) was proved. Using the above-mentioned method and technique, wheat quality characters can be improved. According to the principle of recurrent selection, good genes were introduced into the population via controlled pollination，the bad quality genotypes were eliminated before flowering by molecular marker assisted selection，high quality genes were recombined，accumulated and polymerized by inter-crossing male-sterile plants with fertile ones，thus the frequency of high quality genes were increased.

Key words: Taigu genic male-sterile wheat, Population improvement, Molecular marker, HMW-GS, SDS-PAGE