TITLE:
Does Selection for Seedling Tiller Number in Perennial Biomass Feedstocks Translate to Yield and Quality Improvements in Mature Swards?
AUTHORS:
Robert B. Mitchell, Kenneth P. Vogel, Susan J. Tunnell, James L. Stubbendieck
KEYWORDS:
Seedling Tiller Number, Perennial Biomass
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.11,
November
9,
2023
ABSTRACT: Breeding for seedling traits in herbaceous perennial biomass feedstocks
that translate into increased biomass yield or quality in established swards
could accelerate the development of perennial
grass cultivars for bioenergy or forage. In previously reported
research, breeding for single large tillers (ST) or multiple tillers (MT, ≥3) six weeks
after planting for two generations in big bluestem (Andropogon
gerardii Vitman) and
switchgrass (Panicum virgatum L.)
base populations produced ST and MT populations that differed significantly for
seedling and mature plant traits including biomass yield in spaced planted
nurseries. Our objective was to evaluate these ST and MT populations in sward trials to determine the effect of these
genetic changes on biomass yield and quality when the plants were grown in
competitive sward conditions. Big bluestem monocultures of the base, ST,
and MT populations were evaluated at three
locations in Nebraska in 2001 and 2002 as randomized complete block experiments with four replicates.
Switchgrass monocultures of the base, ST, and MT populations were
evaluated in 2003, 2004, and 2005 near Mead, NE as a randomized complete block
with six replicates. In both big bluestem and switchgrass, the ST and MT
populations did not consistently differ from the base population or each other
for biomass yield or forage quality. These
results demonstrate the importance of evaluating perennial grasses in sward
trials and not relying solely on greenhouse-grown plants or space-planted nurseries to develop selection criteria and make selection
decisions.