TABLE 1.
Application of different classical techniques in crop improvement.
| Crops | Traits improved | Target genes | Remarks | References |
|---|---|---|---|---|
| Domestication | ||||
| Rice | Plant architecture | Prostrate growth 1 (PROG1) | Upright plant growth | Jin et al. (2008) |
| Tan et al. (2008) | ||||
| Number of grains per panicle | Frizzy panicle (FZP gene | Boosted number of secondary branches | Huang et al. (2018) | |
| Seed shattering | SHA1 (a single dominant gene Shattering 1)/SH4 (Shattering 4) and QTL present in chromosome 1(qSH1) controls seed shattering | Reduced shattering of seeds | Li et al. (2006) | |
| Konishi et al. (2006) | ||||
| Lin et al. (2007) | ||||
| Sweeney and McCouch (2007) | ||||
| Vaughan et al. (2008) | ||||
| Seed dormancy | Seed dormancy 4 on chromosome 7 and OsG on chromosome 4 | Genes governing seed dormancy | Sugimoto et al. (2010) | |
| Wang et al. (2018a) | ||||
| Maize | Apical dominance | tb1gene (Teosinte branched1) | Regulating the inflorescence architecture | Doebley et al. (1997) |
| Cubas et al. (1999) | ||||
| Increase in ear | zfl2 (Zeafloricaula leafy2) | Increase in ear rank number | Bomblies and Doebley (2006) | |
| Sexual conversion | tru1 gene (tassels replace upper ears1) | Conversion of a tassel in teosinte to an ear | Doebley et al. (1995) | |
| Dong et al. (2017) | ||||
| Chen et al. (2019) | ||||
| Selection and hybridization | ||||
| Maize | Inflorescence | Remosa 1 (ra1) gene | Ear and tassel are suppressed | Vollbrecht et al. (2005) |
| Sigmon and Vollbrecht (2010) | ||||
| Xu et al. (2017) | ||||
| Chen et al. (2019) | ||||
| Hybrid crop breeding/cross breeding | ||||
| Rice | Yield increases | Cross Breeding | Witcombe et al. (2013) | |
| Increased spikelet number per panicle | Panigrahi et al. (2019) | |||
| Wheat | Grain yield | Basnet et al. (2019) | ||
| Mutation breeding | ||||
| Wheat | Dwarf height of plant | Rht-B1b & Rht-D1b | Single base pair mutation | Peng et al. (1999) |
| Ellis et al. (2002) | ||||
| Rust resistance | Lr34 | SNPs | Dakouri et al. (2010) | |
| Krattinger et al. (2009) | ||||
| Chauhan et al. (2015) | ||||
| Rice | Increased 1000-grain weight | GW2 gene | Loss of function mutation | Song et al. (2007) |
| Higher nitrogen use efficiency | NRT | NRT1.1B (SNP) | Hu et al. (2015) | |
| Li et al. (2018a) | ||||
| Disease resistance (bacterial blight) | Os8N3 | Loss of function mutation | Kim et al. (2019) | |