TY - JOUR

T1 - Plant density modifies root system architecture in spring barley (Hordeum vulgare L.) through a change in nodal root number

AU - Hecht, Vera L.

AU - Temperton, Victoria Martine

AU - Nagel, Kerstin A

AU - Rascher, Uwe

AU - Pude, Ralf

AU - Postma, Johannes A.

PY - 2019/6/15

Y1 - 2019/6/15

N2 - Aim: Previously, we showed that sowing density influences root length density (RLD), specific root length (SRL) especially in the topsoil, and shallowness of fine roots of field grown spring barley (Hordeum vulagre L.). Here, we ask which trait components may explain these observed changes. Method: We grew two spring barley cultivars at contrasting sowing densities in both field trials and rhizotrons, and excavated root crowns and imaged root growth. Results: In the field, tiller and nodal root numbers per plant decreased with increasing sowing density, however, nodal roots per tiller, seminal roots per plant, and lateral branching frequencies were not affected. Branching angle did not or only slightly declined with increasing sowing density. In rhizotrons, aboveground only tiller number was affected by sowing density. Root growth rates and counts were not (or only slightly) affected. Conclusion: Greater RLD at high sowing densities is largely explained by greater main root number per area. The altered seminal to nodal root ratio might explain observed increases in SRL. We conclude that sowing density is a modifier of root system architecture with probable functional consequences, and thereby an important factor to be considered in root studies or the development of root ideotypes for agriculture.

AB - Aim: Previously, we showed that sowing density influences root length density (RLD), specific root length (SRL) especially in the topsoil, and shallowness of fine roots of field grown spring barley (Hordeum vulagre L.). Here, we ask which trait components may explain these observed changes. Method: We grew two spring barley cultivars at contrasting sowing densities in both field trials and rhizotrons, and excavated root crowns and imaged root growth. Results: In the field, tiller and nodal root numbers per plant decreased with increasing sowing density, however, nodal roots per tiller, seminal roots per plant, and lateral branching frequencies were not affected. Branching angle did not or only slightly declined with increasing sowing density. In rhizotrons, aboveground only tiller number was affected by sowing density. Root growth rates and counts were not (or only slightly) affected. Conclusion: Greater RLD at high sowing densities is largely explained by greater main root number per area. The altered seminal to nodal root ratio might explain observed increases in SRL. We conclude that sowing density is a modifier of root system architecture with probable functional consequences, and thereby an important factor to be considered in root studies or the development of root ideotypes for agriculture.

KW - Ecosystems Research

KW - Nodal & seminal roots

KW - tiller counts

KW - lateral branching frequency

KW - branching angle

KW - lab to field

KW - plant competition

KW - Nodal & seminal roots

KW - Tiller counts

KW - Lateral branching frequency

KW - Branching angle

KW - Lab to field

KW - Plant competition

UR - http://www.scopus.com/inward/record.url?scp=85052616756&partnerID=8YFLogxK

U2 - 10.1007/s11104-018-3764-9

DO - 10.1007/s11104-018-3764-9

M3 - Journal articles

VL - 439

SP - 179

EP - 200

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

IS - 1-2

ER -