Aims: Root angles are widely recognized to play an important role in determining rooting depth and drought tolerance in crop plants. But there has been no report revealing any association between root angle and yield performance under drought conditions in maize. There is also no simple method available to screen root angles. The objectives of this study were to evaluate genetic variation in seminal and nodal root angles in maize in greenhouse condition and their association with drought tolerance in field condition. Methods: Eighteen hybrids, of which nine were higher-yielding and nine were lower-yielding under water-stressed condition in field, were evaluated for root angle variation. Root angle was estimated as the distance between the horizontal soil surface line and slope of the root at 2 cm position from root base using a protractor. Results: Significant phenotypic variation was observed among hybrids for seminal and nodal root angles and primary root diameter. These root traits showed strong positive correlations with grain yield under drought condition. All the higher-yielding hybrids had steeper root growth angle than the lower-yielding hybrids. A strong correlation between seminal and nodal root angles was observed. A strong correlation was also observed between 5th and 4th node nodal root angles. Conclusion: Either seminal or nodal root angle could be used for selection for the improvement drought tolerance. The current screening system for root angle is simple and inexpensive, and could be used for screening a large number of genotypes.
|Original language||English (US)|
|Number of pages||13|
|Journal||Plant and Soil|
|State||Published - Dec 1 2015|
Bibliographical noteFunding Information:
The research was supported by the UNL Life Sciences Competition and Nebraska Corn Board. Sincerest thanks are extended to Jeff Golus, Rachelle Hanson, Jennifer Sherman (technologists) and Jefferson Cox (undergraduate student) for their help in planting, harvesting and various field activities; to Nonoy Bondillo, D.C. Kadam, Amritpal Singh (graduate students); Ryan Luetkenhaus (undergraduate student) for help in root harvesting in greenhouse.
© 2015, Springer International Publishing Switzerland.
- Deep rooting
- Drought tolerance
- Nodal root angle
- Primary root diameter
- Seminal root angle