TITLE:
Growth and Yield Responses of Switchgrass Ecotypes to Temperature
AUTHORS:
Tanka Prasad Kandel, Yanqi Wu, Vijaya Gopal Kakani
KEYWORDS:
Biomass Partitioning; Chemical Composition; Growth Response; Switchgrass; Temperature
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.6,
June
10,
2013
ABSTRACT: Varietal
differences of switchgrass in growth and development, biomass yield and
partitioning in response to temperature are not well documented. A study
was conducted to quantify the effect of temperature on growth, development, and
feedstock quality of switchgrass cultivars, and to determine differences
between upland and lowland switchgrass. Two lowland (“Alamo” and “Kanlow”) and two upland (“Caddo” and “Cave-in-Rock”) cultivars of switchgrass
were grown in pots filled with pure, fine sand in growth chambers. Four
different temperature treatments of 23℃/15℃, 28℃/20℃, 33℃/25℃, and 38℃/30℃ with 14/10
hours day/night were imposed at four leaf stage. High temperature significantly
decreased the biomass yield across all cultivars. Stem elongation rate (SER)
and leaf elongation rate (LER) decreased at the highest temperature treatment
but lowland cultivars had significantly higher SER and LER across the temperature
treatments. Upland cultivars produced more tillers across the temperature
treatment. Both shoot/root and leaf/stem ratios increased under the
highest temperature in all cultivars, but upland cultivars partitioned more to
the leaf and root at higher temperature. Concentration of cellulose decreased
at the highest temperature but temperature had no effect on lignin
concentration of leaf and stem biomass. In conclusion, although none of the
cultivars studied showed strong tolerance to high temperature,
differences were observed for many traits of switchgrass in response to
temperature.