Roots play an important role early in plant growth and development and are involved in stress response and nutrient and water absorption. Researchers have previously identified DNA sequences associated with root traits, but these sequences have not been used in breeding programs. 

Scientist Chuanli Ju from National Maize Improvement Center of China and colleagues identified 36 putative quantitative trait loci (QTLs) associated with maize root traits, including primary root length, total number of the primary, seminal, and crown roots, lateral root number, total root tip number, total root length, total root surface area, total root volume, and average root diameter. They analyze these root traits at three time points after germination using the recombinant inbred line population (RIL) Zong3 x Yu87-1. 

Notably, they found pleiotropic QTLs associated with more than one root trait. Some of these QTLs are also associated with important agronomic traits (grain yield, plant height, stress response) previously identified using the same RILs. These traits have strong to moderate correlation with the QTLs. These QTLs will be particularly useful in marker-assisted selection of maize plants simultaneously containing useful root and agronomic traits.

For more information, read the article in BMC Plant Biology.