Screening and genetic analysis of the aroma mutants derived from a mutation pool of IR64 rice variety

• Main Authors: Wei-Hao Chen, 陳韋豪
• Other Authors: Chang-Sheng Wang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/34179395334699681270

碩士 === 國立中興大學 === 農藝學系所 === 102 === Rice is an important food crop. Among rice varieties, aroma rice produced a pleasant and subtle fragrance when cooked. Aroma rice gaining widespread popularity among consumers worldwide, thus the price is much higher than that of non-fragrant rice in international market. This inspires many researchers and plant breeders to conduct genetic analysis and include fragrance as one of the important economic trait rice breeding. In our laboratory, an aroma mutant IR64A (A01) was screened at the M5 generation from the IR64 sodium azide induced mutation pool. Genetic analysis and mapping reveals that the fragrant gene was monogenic recessive inheritance and the badh2 on chromosome 8 was found to be the major gene responsible for fragrance. Fragrance evaluation was conducted on brown rice of 900 mutant lines of IR64 mutation pool at the M10 generation and obtained a series of aroma mutants namely, A02, A03, A04, A06, A07, A08, A09, A12, A13, A14, A15, A16, A18, and A19, as a core collection for fragrance research and breeding A08 is tall, large grain and with a similar aroma as IR64A while A04 has long awn, small grain and stable aroma characteristics. Genetic analysis between IR64/A04 and IR64/A08 F2 populations found the aroma trait of both A04 and A08 are monogenic recessive inheritance. Besides, allelism test of IR64A/A04 and IR64A/A04 F2 populations showed that badh2 is the major gene. Genotyping by functional markers FMbadh2-E2 (badh2.2) and FMbadh2-E7 (badh2.1) revealed an 8 bp deletion on the exon 7 in IR64A and A19, which belong to badh2.1 genotype. Re-sequencing and phylogenetic analysis also found a C→T single nucleotide polymorphism (SNP, badh2.10) on the exon 13 in A04, A08 and other aroma mutants, correlation analysis showed badh2.10 is highly correlated to aroma. Establishment of functional markers FMbadh2.10 and genetic analysis of the four F2 populations demonstrated a high correlation between genotype and leaf aroma (R=0.88). This confirmed that badh2.10 affects the function of BADH2 protein hence produce fragrance, and different aroma genotypes may also influence the degree of aroma.