Table 2.
Structural and functional root traits identified as potentially relevant for drought-resistance breeding.
| Traits | Species | QTLs | Sources |
|---|---|---|---|
| Root length | Rice, Wheat, Maize | Yes | Price et al., 2002; Tuberosa et al., 2002a,b; MacMillan et al., 2006; Courtois et al., 2009 |
| Root biomass | Rice | Yes | Courtois et al., 2003 |
| Root thickness | Rice, Maize | Yes | Zheng et al., 2000; Tuberosa et al., 2002a,b |
| Total root biomass | Wheat, Maize | Yes | Tuberosa et al., 2002a,b; Sharma et al., 2011 |
| Root length density (RLD) | Chickpea | No | Kashiwagi et al., 2005 |
| Seminal root angle | Wheat | Yes | Christopher et al., 2013 |
| Number of seminal roots | Wheat | Yes | Christopher et al., 2013 |
| Crown root angle | Maize, Sorghum | Yes | Giuliani et al., 2005; Singh et al., 2010, 2012 |
| Rooting depth | Wheat, Chickpea | No | Sayar et al., 2007; Varshney et al., 2014 |
| Crown root diameter | Maize | Yes | Giuliani et al., 2005 |
| Xylem vessel size and number | Rice, Wheat | Yes | Richards and Passioura, 1989; Uga et al., 2008 |
| Root cortical aerenchyma | Maize | Yes | Mano and Omori, 2009 |