The technology, known as TILLING (Targeting Induced Local Lesions IN Genomes) is a 'reverse genetics' process as developed by Colbert et. al. 2001. The method relies on the ability of a special enzyme to detect mismatches in normal and mutant DNA strands when they are annealed. Seed was treated with ethylmethanesulphonate (EMS) to generate a population of plants with random point mutations. By selectively pooling the DNA and amplifying with fluorescently labelled primers, mismatched heteroduplexes were generated between wild type and mutant DNA. Heteroduplexes were incubated with the plant endonuclease CEL I, (cleaves heteroduplex mismatched sites)and the resultant products visualised on a ABI3730. Subsequent analysis of the individual plant DNA from the pool DNA identified the plant bearing the mutation.
Seed Mutagenesis, irradiation, Optimizing Gamma Irradition, Optimizing Chemical Mutagenesis, EMS
Mutant Population M1,M2 and M3
Create Heteroduplexes, DNA Isolation, PCR Amplification, Create Heteroduplexes, Cleave mismatch products, Gel electrophoresis, Sequencing
Amino acid, HPLC
Gel Image Analysis
Analyzing Mutant Individuals
ALI BENJAVAD TALEBI
DR. CHE RADZIAH BINTI CEH MOHD ZAIN
DR. ZAMRI BIN ZAINAL
PROF. DR. MOHAMAD BIN OSMAN
NEW rice variety, MR 219, has been developed by the Malaysian Agricultural Research and Development Institute (MARDI). It was officially released in January, 2001. It was the first variety to be developed by means of a direct seeding planting system. Selection from F2 to F6 of the segregating generations was done visually, using a direct seeding system. The emphasis was on the panicle component characters, mainly the grain size and the number of grains per panicle. As a result, a single grain of MR 219 variety can weigh as much as 28 – 30 mg, and the number of grains can be as high as 200, higher than that of rice varieties previously released
A gene in rice that controls the size and weight of rice grains has been identified, and may thus be useful for breeding high-yield rice."The GIF1 gene is responsible for controlling the activity of the enzyme invertase, which is located in the cell wall and converts sucrose to substances that then are used to create starch. Invertase is important in the formation of starch within developing grains of rice. If invertase is not active, the rice plant cannot produce edible grains.” The scientists found that invertase activity in the mutant strain was only 17 percent of the activity that was observed in the normal strain, suggesting that the GIF1 gene does, indeed, control invertase activity.
The technology, known as TILLING (Targeting Induced LocalLesions IN Genomes) is a 'reverse genetics' process as developed by Colbert et. al. 2001. The method relies on the ability of a special enzyme to detect mismatches in normal and mutant DNA strands when they are annealed.