FAO/IAEA International Symposium on Plant Mutation Breeding and Biotechnology

GAMMA RAYS APPLICATION IN THE DEVELOPMENT OF RICE LINES TOLERANT TO ARYLOXYPHENOXYPROPIONATE HERBICIDES

Not scheduled

20m

IAEA, Vienna

Oral Enhancing agricultural biodiversity through new mutation induction techniques

Speaker

Dr Alexander De Andrade (Epagri)

Description

The aryloxyphenoxypropionate herbicides (APPs) are graminicides with excellent control of many grass weeds species, including weedy rice (Oryza sativa L.). These herbicides block the fatty acid biosynthesis by inhibition of the enzyme acetyl-CoA carboxylase (ACCase), and cause the death of the plant. Inducing mutation by applying gamma rays to seeds, two rice lines resistant to APPs herbicides were developed. Plant dose-response assays confirmed the resistance to the APPS herbicides quizalofop-p-ethyl and haloxyfop-p-methyl. The carboxyl-transferase (CT) domain fragments of ACCase from the resistant biotype and susceptible control were sequenced and compared. A point mutation was detected in the amino acid position 2027 (Rice Genome Annotation Project: Os05g22940.1). Results indicated that resistance to APPs is a consequence of an altered ACCase enzyme that confers resistance. The use of APPs herbicide resistant rice lines represents an innovative and promising alternative for weedy-rice control in paddy rice systems.