Table 4. Examples of induced mutation types and frequency in food crops using TILLING or exome resequencing genomic analyses.
NaN3-MNU, Sodium azide-methyl-nitro urea; TILLING, targeting induced local lesions in genomes.
| Plant (Assembled Genome Size)a | Mutagen | No. of Plants Analyzed | Reported Mutation Density (Calculated Mutation Frequency)b | Number of Genes/Genomic Regions Analyzedc (Total Mb Analyzed) | Reference |
|---|---|---|---|---|---|
| Rice (O. sativa; 375 Mb) | NaN3-MNU | 768 | 1 SNP/265 kb (3.8 × 10−6) | 10 genes (7.9 Mb total) | Till et al., 2007 |
| Maize (Z. mays; 2,400 Mb) | EMS | 1,086 | 1 SNP/774 kb (1.3 × 10−6) | Whole-exome resequencing (139 Mb/plant) | Lu et al., 2018 |
| Wheat (Triticum aestivum; 14,540 Mb) | EMS | 1,535 tetraploid 1,200 hexaploid | 23 SNPs/Mb (4n; 2.3 × 10−5) | Whole exome resequencing (119 Mb/plant [4 n]; 162 Mb/plant [6 n]) | Krasileva et al., 2017 |
| 33 SNPs/Mb (6n; 3.3 × 10−5) | |||||
| Barley (H. vulgare; 8,050 Mb) | NaN3 | 3,148 | 1 SNP/374 kb (2.7 × 10−6) | 4 genes (8.2 Mb total) | Talamè et al., 2008 |
| Cotton (Gossypium hirsutum; 2,100 Mb) | EMS | 8,000 M2 lines (2 varieties) | 1 SNP/153 kb (6.5 × 10−6); 1 SNP/326 kb (3.1 × 10−6) | 8 genes (58.1 Mb/variety) | Aslam et al., 2016 |
| Tomato (S. lycopersicum; 950 Mb) | EMS | 1,352 M3 lines | 1 SNP/322 kb (3.1 × 10−6) | 7 genes (10.9 Mb total) | Minoia et al., 2010 |
a
Assembled genome size is taken from the EnsemblPlants database (http://plants.ensembl.org).
b
Mutation density (mutations per kilobase or Megabase) is as reported and was determined by dividing the total genomic region evaluated (kilobase) by the number of nucleotide changes observed. Calculated mutation frequency is the arithmetic calculation of mutations per nucleotide site per experiment.
c
Numbers of genes or genomic regions analyzed in mutagenized plants are as reported. The total DNA length analyzed across all plants and genes (for TILLING) or per plant (for exome sequencing) is also included.