TITLE:
Genetic Diversity in the Environmental Conditioning of Two Sorghum (Sorghum bicolor L.) Hybrids
AUTHORS:
John J. Burke, Yves Emendack, Chad Hayes, Junping Chen
KEYWORDS:
Sorghum, Sorghum bicolor L., Thermal Sensitivity, Adaptation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.4,
March
28,
2018
ABSTRACT: Sorghum metabolism continually adapts to
environmental temperature as thermal patterns modulate diurnally and
seasonally. The degree of adaptation to any given temperature may be difficult
to determine from phenotypic responses of the plants. The present study was
designed to see if the efficiency of quantum yield of photosystem II could be
used as a measure of how well leaf tissue metabolism was able to withstand a
prolonged respiratory demand caused by elevated temperatures. The efficiency of
quantum yield values of Pioneer 84G62 and Northrup King KS585 commercial
sorghum hybrids showed that when the hybrids were grown in a
28°C/20°C day/night cycle in the greenhouse or the field,
Pioneer hybrid 84G62 withstood subsequent elevated thermal challenges better
than Northrup King KS585. The same hybrids grown in a 39°C/32°C
day/night cycle showed similar efficiency of quantum yield values when
thermally challenged. Water-deficit stress increased the heat resistance of the
tissue raising the efficiency of quantum yield of both lines to the same level.
Upon recovery from the water deficit stress the differential efficiency of
quantum yield values between the two lines re-appeared. The data provided in
this study suggest a metabolic advantage of Pioneer 84G62 to environmental
thermal challenges compared with the Northrup King KS585.