Identification of Molecular Marker Linked to Salt Tolerance Gene in Alfalfa

摘要

The study has established the F_2 offspring obtained by crossing salt-tolerant with salt-sensitive alfalfa, and appraised the salt-tolerant F_2 offspring seedling was evaluated in pot culture. With the F_2 segregated population, the research has obtained a molecular marker linked with salt-tolerant genes of alfalfa using the improved BSA combined with RAPD. The RAPD PCR products were excised from the agarose gel and purified using a kit, then were mixed with pMD-18T vector and sequenced. Sequencing result indicated the RAPD marker was 1 438 bp in length. Similarity researches using blast in Genbank indicated that the nucleotide sequence of the RAPD marker showed 93% and 91% similarity with mth2-6e!8 gene fragment (347 bp) and mth2-33122 gene fragment (334 bp) of Medicago truncatula respectively. Medicago truncatula is a close relative of alfalfa and Mth2-6el8 is a molecular marker of the gene coding for a cysteine protease which was salt-inducible in some plants. These results indicated the RAPD marker was possibly related to cysteine protease genes in alfalfa.