Data from: Root responses to domestication, precipitation and silicification: weeping meadow grass simplifies and alters toughness

Background and aims: Plant breeding usually focuses on conspicuous
above-ground plant traits, yet roots fundamentally underpin plant fitness.
Roots show phenotypic plasticity in response to soil conditions but it is
unclear whether domesticated plants respond like their ancestors. We aimed
to determine how root traits differed between ancestral and domesticated
types of a meadow grass (Microlaena stipoides) under altered regimes of
precipitation and soil silicon availability. Methods: We subjected the two
grass types to three simulated precipitation regimes (ambient, +50%/deluge
and − 50%/drought) in soil with (Si+) and without (Si−) silicon
supplementation and then characterised root biomass, architectural
complexity and toughness in addition to shoot traits. Results:
Domestication increased root tissue density, decreased specific root
length (SRL) and decreased root architectural complexity. Domestication
also increased root strength under Si − conditions but not
Si + conditions. Fine roots, SRL, architectural complexity and the force
required to tear the roots all decreased under deluge. The ancestral and
domesticated grasses responded similarly to precipitation, except that the
latter had weaker roots (decreased fracture strain) under drought.
Conclusions: Domestication and increased precipitation caused changes in
M. stipoides root traits that could be beneficial against some stresses
(e.g. soil compaction, herbivory) but not others (e.g. drought).