June 9, 2006
Sorghum is one of the world’s most
important grain crops, and scientists have been seeking to
improve it. The introduction of cold tolerance in sorghum
cultivars would be very beneficial, as this trait would allow
sorghum to be planted in more places, and in the early spring,
when soil moisture is higher. To improve sorghum, scientists
need to identify a superior germplasm with cold tolerance.
With this aim, Cleve D. Franks
and colleagues of the United
States Department of Agriculture conducted “A Comparison
of U.S. and Chinese Sorghum Germplasm for Early Season Cold
Tolerance,” and report in a recent issue of Crop Science.
Their research focused on sorghum lines and hybrids from Chinese
landrace accessions of the working group Nervosum-Kaoliang;
publicly available inbred lines from the Texas Agricultural
Experiment Station sorghum breeding program; and U.S. grain
sorghum hybrids provided by seed companies.
Chinese accessions were
compared with 10 U.S. inbred parental lines and 10 U.S.
commercial hybrids for cold tolerance under laboratory, growth
chamber, and field settings. After tests and statistical
analysis, scientists found that: 1) Chinese lines were superior
to the other lines, in terms of laboratory germination rates and
field-based rates of emergence; 2) Chinese lines were not
significantly different from hybrid lines in growth chamber
assays, except for shoot length, for which the Chinese germplasm
was higher; and 3) although Chinese lines had higher germination
rates and lower germination temperature thresholds, they had no
advantage in terms of biomass production.
Researchers thus concluded that
the accessions could serve as a source of genes for cold
tolerance during the germination and emergence phase of growth
in the breeding of better sorghum lines.
Subscribers to Crop Science can
read the complete article at