Abstract: In order to obtain the fragrant rice varieties with higher economic value, two target sites were designed on Badh2 gene using CRISPR/Cas9 technology to improve the fragrance quality of super rice Longjing 31, the sgRNA-E2 between intron 2 and exon 2, and the sgRNA-E3 on exon 3 of Badh2 gene, respectively. Six transgenic lines were detected with base deletion, insertion and mutation, among which, four lines were di-allelic mutation and two lines were homozygous mutation. Large fragment deletion occurring in the di-allelic mutation Badh2-E2-13 with lack of 64,108 bp.qRT-PCR results indicated that companed with the wild type the transcriptional level of Badh2 declined significantly (P<0.05) in the six mutants. The fragrance content of 2AP increased dramatically (P<0.05) in the five mutations compared with wild type using gas chromatography-mass spectrometry (GC-MS) method, two of them achieved positive control (Xinxiangjing 1) level, in which one was significantly improved. The main agronomic traits of the T₁ of the 6 mutant lines were investigated, indicating that there was no significant difference between the wild type and the 3 lines, which of the fragrance content increased. Further, screening the marker gene of T₁ lines, 10 transgenic-free individuals were obtained. Comprehensively,the Badh2 gene was successfully edited by CRISPR/Cas9 technology in Longjing 31, increasing 2AP content of Longjing 31 remarkably, which would provide suitable material for fragrant and super rice breeding.

Key words: Fragrant rice, Longjing 31, CRISPR/Cas9, 2-acetyl-1-pyrroline, Badh2

CLC Number: 

• Q78

• S511.03