AUTHOR=Wang Zhi , Xu Weizhou , Chen Zhifei , Jia Zhao , Huang Jin , Wen Zhongming , Chen Yinglong , Xu Bingcheng 

TITLE=Soil Moisture Availability at Early Growth Stages Strongly Affected Root Growth of Bothriochloa ischaemum When Mixed With Lespedeza davurica

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 9 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.01050

DOI=10.3389/fpls.2018.01050

ISSN=1664-462X

ABSTRACT=Rainfall is the main resource of soil moisture in the semi-arid areas, and the altered rainfall pattern would greatly affect plant growth and development. Root morphological traits are critical for plant adaptation to changeable soil moisture. This study aimed to clarify how root morphological traits of Bothriochloa ischaemum (a C4 herbaceous species) and Lespedeza davurica (a C3 leguminous species) in response to variable soil moisture in their mixtures. The two species were co-cultivated in pots at seven mixture ratios under three soil water regimes [80% (HW), 60% (MW), and 40% (LW) of soil moisture field capacity (FC)]. At jointing, flowering and filling stages of B. ischaemum, the LW and MW treatments were re-watered to MW or HW, respectively. At the end of growth season, root morphological traits of two species were evaluated. Results showed that root morphological response of B. ischaemum was more sensitive than that of L. davurica under re-watering. Total root length (TRL) and root surface area (RSA) of both species increased as their mixture proportion decreased, which suggested that mixed plantation of the two species would be beneficial for their own root growth. Among all treatments, the increase of root biomass (RB), TRL and RSA reached the highest levels when soil water content increased from 40% to 80% FC at jointing stage. Our results implied that species-specific response in root morphological traits to alternated rainfall pattern would greatly affect community structure, and large rainfall occurring at early growth stages would greatly increase their root growth in the semi-arid environments.