Construction Of A Mutant Library Of Common Wheat Cultivar Shaannong33 Mutated With Sodium Azide And Selection Of Mutants

With the development of sequencing, the construction of mutant libraries is becoming more and more important. A mutant library can not only provide study materials for functional genomics, but also provide applying materials for crop breeding. Chemical mutagenesis is one of the most important ways of mutant library construction. In this research seeds of wheat cultivar shaannong33 was treated with 0, 5, 10, 15, 20mmol?L-1 concentrations of sodium azide, respectively. The appropriate mutagenesis concentration was screened out primitively through laboratory germination test indexes According to the statistic result, 10mmol?L-1 was accepted to be the appropriate mutagenesis concentration. A M2 population was derived from the M1 population treated with 10mmol?L-1 sodium azide by self-fertilization. Phenotypic mutants were screened out by observation in the whole growth period of M2 and TILIING was used to screen out mutants of the designated genes, RAPD was used to evaluate the mutation density of the M2 population. Phenotypic mutants were continuously to be screened out by observation in the whole growth period of M3 and the heritability of the mutants which were found during the M2 period was authenticated. The main research findings were as follows:1. The validation of appropriate mutagenesis concentration: All the indexes of 5mmol?L-1 treatment were significant comparing to the contrast treatment, and all the indexes were not significant between the 15mmol?L-1 treatment and the 20mmol?L-1 treatment. The mutagenic degree of 10mmol?L-1 treatment was moderate, and the raw weight of root and the length of main root of 10mmol?L-1 treatment were about half of the contrast treatment, and the field survival rate was only 42.3%.2. The screening and validation of phenotypic mutants: 834 individual plants were obtained from the 10mmol?L-1 treatment, and a M2 population of 3942 individual plants was obtained after sowing. 322 individual plants from 108 lines showed one or more phenotypic mutation types among this M2 population, the total mutation rate was 8.17%. Of these mutants were 204 stem character mutants, 65 leaf character mutants, 24 spike mutants and 115 other character mutants. Among these phenotypic mutants which were found during the M2 growth period, 58 lines were validated to be stably inheritable. Including 32 plant height mutation lines, 17 leaf color mutation lines, 3 spike mutation lines, 2 tiller mutation lines, 1 leaf shape mutation line and 1 plant type mutation line. The average mutation rate of the population was 1/57.0kb by RAPD.In summary: 10mmol?L-1 was preliminarily screened out to be the appropriate mutagenic concentration of sodium azide to common wheat. A M2 population was derived from the M1 population treated with 10mmol?L-1 sodium azide, and abundant phenotypic mutation types and plentiful phenotypic mutants were found among the M2 population. These mutants could be study materials and applied materials for wheat functional genomic research and wheat breeding.