Analysis of the Dwarfing Mutagenic Effect on a Wheat Mutant Line DMR88-1 by Space Mutation

DMR88-1 is a stable inherited dwarf mutant wheat( Triticumaestivum L.) line,which was developed from the wheat cultivar CN19( original No. R88) carried by the recoverable satellite Shijian- 8 in 2006. To understand dwarfing mutagenic effect by spatial environment, the plant height and growth development, stalkanatomical histological characteristics and DNA molecular variation were analyzed on the dwarf mutant DMR88-1. A tall mutant HMR88- 1similarly developed from CN19 carried by the Shijian- 8 and the elite variety CN19( also named R88CK) were used as the control materials in the study. The results showed that the average plant height of DMR88-1 was 59. 02 cm,23. 73%lower than R88 CK. The plant height reduction of DMR88-1 was mainly caused by the shortening of internode length,while there existed no difference in the number of internodes. The shortening effect of uppermost internode length was more than the other internodes by 42. 48% contribution rate,which was mainly attributed to the reduction of the cell length and cell number. Some special SSR( simple sequence repeat) molecular markers for dwarfing genes widely existed in wheat cultivars were applied in the experiment. The results indicated that R88 CK did not carry those dominant dwarfing genes. SSR markers analysis showed 26 pairs of primers were identified with polymorphism among R88 CK,DMR88-1,and HMR88- 1,and 6 types of mutation bands amplified. The PCR-amplified products were sequenced,and 17 of these sequences had the BLAST functional annotations. The molecular mechanism of dwarfing mutagenesis by spatial environment was discussed in this paper. Our study laid a foundation for further research of DMR88-1 dwarfing mechanism and space mutation breeding mechanism.