SMART--Sunflower Mutant population And Reverse genetic Tool for crop improvement.

Area of Science:

• Plant genetics and breeding
• Molecular biology
• Agricultural science

Background:

• Sunflower (Helianthus annuus L.) is a globally significant oilseed crop.
• Classical genetics has been used for sunflower improvement.
• A novel chemically induced mutated genetic resource for Single Nucleotide Polymorphism (SNP) detection by TILLING was developed for sunflower.

Purpose of the Study:

• To create a valuable genetic resource for sunflower crop improvement.
• To identify new traits in sunflower through induced mutations.
• To establish a TILLING (Targeting Induced Local Lesions IN Genomes) platform for sunflower.

Main Methods:

• Optimized ethyl methanesulfonate (EMS) mutagenesis using a "kill curve" analysis to determine the LD50 (lethal dose for 50% of subjects).
• Generated 5,000 M2 populations and 4,763 M3 plants with fertile seeds.
• Established a sunflower TILLING platform utilizing Endo-1-nuclease and an eight-fold DNA pooling strategy.

Main Results:

• A dose of 0.6% EMS for 8 hours yielded a 50% survival rate.
• Phenotypic characterization of 5,000 M2 lines revealed approximately 1.1% exhibited variations.
• Screening identified 26 mutations in the FatA and SAD genes involved in fatty acid biosynthesis.

Conclusions:

• The overall mutation rate was calculated at one mutation per 480 kb, consistent with previous findings.
• The developed genetic resource is anticipated to be a valuable tool for discovering novel traits in sunflower.
• This resource will aid in the improvement of sunflower as a model plant for seed oil biosynthesis.